Commit Graph

151 Commits

Author SHA1 Message Date
Nikolay Edigaryev f80df6d4f1 Sort operations to guarantee a stable order (#156)
Problem: currently when using a wildcard that covers multiple files in `operations:` YAML directive the generator emits functions in a non-stable ordering due to the use of map for storing file names:

https://github.com/Khan/genqlient/blob/e0accbded177db9143314911bacedf61b2cda656/generate/parse.go#L68-L84

Solution: sort the operations before emitting them.
2021-11-26 12:32:03 -08:00
Nathan Stitt 2fdbb629be Add "struct_references" configuration (#155)
Adds a "struct_references" configuration that will:

* Use a pointer type for struct fields that are a complex type
* The behaviour can be overridden by setting "pointer: false" in the
  proceeding comment blocks
* Sets the "omitempty: true" flag on fields matching the criteria.
  This can also be overriden by setting "omitempty: false"

Although we'd debated not setting the pointer for array elements, it did turn out to be simpler to set them everywhere and also made the documentation cleaner to have a single rule to explain.

Fixes #149.
2021-11-12 19:53:19 -08:00
Florian Suess e0accbded1 Allow compatibility when using introspection derived client schema's (#145)
During generation we parse the schema using [`gqlparser.LoadSchema`](https://github.com/vektah/gqlparser/blob/2a3d320c0f1d31f404cc36f6cce8f7f93b016682/gqlparser.go#L11) over [here](https://github.com/Khan/genqlient/blob/a4aa6d9bb0f45cb71b3b7816742172011d96fbc1/generate/parse.go#L34). As you can see `gqlparser.LoadSchema` uses it's sub directory declared [`validator.LoadSchema`](https://github.com/vektah/gqlparser/blob/2a3d320c0f1d31f404cc36f6cce8f7f93b016682/gqlparser.go#L12) - but prepends a schema with [typical implicit declared types](https://github.com/vektah/gqlparser/blob/2a3d320c0f1d31f404cc36f6cce8f7f93b016682/validator/prelude.go#L5). Full server schema introspection exposes the entire schema explicitly, hence causing a clash with this prelude schema rendering introspection derived schemas to fail.

Here I just introduce a two stage schema parsing step to accomodate both implicit and explicit sdl's.

--

I have also added to the FAQ as per https://github.com/Khan/genqlient/issues/4 how we can use introspection to fetch the schema when using `genqlient`.

Co-authored-by: Ben Kraft <ben@benkraft.org>
2021-10-27 15:27:37 -07:00
John Maguire 10dc388016 Walk parent directories to find config file (#141)
Code is mostly borrowed from [gqlgen](https://github.com/99designs/gqlgen).

The idea here is that I want to be able to store `genqlient.yaml` at the top-level, but my client code lives down in `graph/client/`. I put the `//go:generate` line in `graph/client/client.go`.
2021-10-21 21:43:34 -04:00
John Maguire 9ecc62e285 Fix error handling during config init (#142)
Previously initConfig always returned an error even if it succeeded.
This resulted in a confusing CLI error message that did not match the
executed behavior.

Now it returns an error only if it fails to init the config.
2021-10-21 11:46:01 -07:00
Ben Kraft 22019287da Align support for multiple operation-files and multiple schema-files (#137)
Multiple schema-files are now supported as of #134, but the support was
a bit different from how we did multiple operation-files.  Before anyone
starts to depend on the ways the syntaxes differ, let's just make them
the same.  Since it's easy, I also added support for having just a
single operations-file.

I also realized while writing this that the type-change is technically
breaking (if you call from Go), so documented it as such. I think
this is unlikely to affect many people.

Test plan: make check
2021-10-05 12:52:48 -07:00
Craig Silverstein a52e55632f Allow creating aliases for builtin types, using typename. (#133)
## Summary:
This lets you write code like:
```
query x {
   # @genqlient(typename: "MyString")
   someStringField
}
```
and genqlient will do
```
typename MyString string
type x struct {
   someStringField MyString
}
```

This was not difficult to implement, though it required introducing a
new identifier type.  The main difficulty I had was weird test
failures, that it turns out was due to the tests putting a bunch of
fields on the same line, so that the genqlient directive on the
previous line applied to all of them, accidentally.  This became a
problem when `typename` suddenly started being respected for builtin
types!  I fixed it by just spreading out the queries a bit.

Fixes #130

## Test plan:
make check

Author: csilvers

Reviewers: dnerdy, StevenACoffman, benjaminjkraft

Required Reviewers:

Approved By: StevenACoffman

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/133
2021-10-05 08:49:50 -07:00
Hasibul Hasan 59b6df6aab ️ Accept array of string as valid input schema path. (#134)
* Fixes #88. Accept array of string as valid input schema path.
2021-10-04 13:33:21 -07:00
Ben Kraft 3a5bf46da4 Add getter methods to all fields, not just where needed (#126)
## Summary:
If your type implements an interface, we add getter methods for the
shared fields, so that those may be accessed via the interface.  But it
turns out occasionally it's useful to have these getter methods when
they don't implement a GraphQL interface, so you can use two
genqlient-generated types in the same function if they have the same
fields.  (This comes up most often when you have a GraphQL union that
maybe should really be an interface, or if you don't yet support
interfaces implementing other interfaces (indeed our parser doesn't
either).  But one can imagine other use cases.)

We can't predict how you want to do that, so we can't generate the
interface, but we can generate the methods, so you can define the
interface and do a type assertion from there.  Since these methods are
pretty simple to generate, we just do it always.  (As with #120, if
binary size becomes an issue we could later add an option to only
generate methods that are truly needed but including them seems like the
better default.)

This also fixes a subtle and rare bug, which would have become much more
common (indeed existing tests caught it).  Specifically, if you have a
query like
```graphql
fragment FragmentOne on T { id }
fragment FragmentTwo on T { id }
query Q {
    f {   # interface type T
        ...FragmentOne
        ...FragmentTwo
    }
}
```
since both `FragmentOne` and `FragmentTwo` request some common field,
say `id`, we generate a method `GetId` on each one.  But since
`FragmentOne` and `FragmentTwo` are both on `T`, we also include their
interfaces in the interface we generate for the type of `f`, `QFT`.  So
`QFT` includes a method `GetId`.  But on the implementations, the two
methods conflict, and neither gets promoted; this causes various code to
fail to compile.  With this change, this would have happened much more
frequently -- even if only one of the two fragments is on `T`, as long
as both request the field.  Anyway, we now generate explicit methods on
each struct for all of its recursively emebedded fields -- using the
logic from #120 to compute them -- so that we don't need to rely on
method-promotion.

## Test plan:
make tesc


Author: benjaminjkraft

Reviewers: csilvers, dnerdy, aberkan, jvoll, mahtabsabet, MiguelCastillo, StevenACoffman

Required Reviewers: 

Approved By: csilvers, dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/126
2021-10-01 15:02:07 -07:00
Ben Kraft dd719deb4e Add a mechanism to specify options on input-type fields (#124)
## Summary:
This has been a bit of a thorn since we started using genqlient in
production: just as you might want to specify, say, `omitempty` on an
argument, you might equally want to specify it on an input-type field.
But there's no obvious syntax to do that, because the input-type field
does not appear in the query (only the schema) so there's nowhere to put
the `# @genqlient` directive.

This commit, at last, fixes that problem, via a new option, `for`, which
you use in an option applied to the entire operation (or fragment), and
says, "actually, apply this directive to the given field, not the entire
operation".  (It's mainly useful for input types, but I allowed it for
output types too; I could imagine it being convenient if you want to say
you always use a certain type or type-name for a certain field.)  It
works basically like you expect: the inline options take precedence over
`for` take precedence over query-global options.

The implementation was fairly straightforward once I did a little
refactoring, mostly in the directive-parsing and directive-merging
(which are now combined, since merging is now a bit more complicated).
With that in place, and extended to support `for`, we need only add the
same wiring to input-fields that we have for other places you can put
directives.  I did not attempt to solve the issue I've now documented
as #123, wherein conflicting options can lead to confusing behavior;
the new `for` is a new and perhaps more attractive avenue to cause it
but the issue remains the same and requires nontrivial refactoring
(described in the issue) to solve.  (The breakage isn't horrible for the
most part; the option will just apply, or not apply, where you don't
expect it to.)

But while applying that logic, I noticed a problem, which is that we
were inconsistently cascading operation-level options down to
input-object fields.  (I think this came out of the fact that initially
I thought to cascade them, then realized that this could cause problems
like #123 and intended to walk them back, but then accidentally only
"fixed" it for `omitempty`.  I guess until this change, operation-level
options were rare enough, and input-field options messy enough, that no
one noticed.)  So in this commit I bring things back into consistency,
by saying that they do cascade: with at least a sketch of a path forward
to solve #123 via better validation, I think that's by far the clearest
behavior.

Issue: https://github.com/Khan/genqlient/issues/14

## Test plan:
make check


Author: benjaminjkraft

Reviewers: csilvers, StevenACoffman, benjaminjkraft, aberkan, dnerdy, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: csilvers, StevenACoffman

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/124
2021-10-01 11:28:29 -07:00
Ben Kraft c6d087c29b Add support for "flattening" fragment-spreads (#121)
## Summary:
One common use of fragment spreads is as the entirety of a field's
selection, e.g.
```graphql
query MyQuery {
  myField {
    ...MyFragment
  }
}
```
In this case, by default, genqlient generates a wrapper type
`MyQueryMyFieldMyType`, which just embeds `MyFragment`.  This makes
sense if you later want to add more fields in addition to the fragment
spread.  But if you don't -- and you did the fragment because you want
to share types, it's an extra layer of indirection.  (Which becomes
especially onerous if `myField` has list type (`[MyType!]`), such that
it's not just an extra attribute-access to get to `MyFragment`.)

The new option `# @genqlient(flatten: true)` simplifies this situation:
if applied to `myField` is skips the wrapper type;
`MyQueryResponse.MyField` will simply have type `MyFragment` (or
`[]MyFragment`, or whatever).  This should hopefully make the `typename`
option, which has more limitations, less necessary.

Note that in #30 the initial idea was to support this for fields as
well.  This would require significant additional complexity in the
JSON-(un)marshaling code, and has proven less necessary, so I
implemented this option only for fragment-spreads for now.  With that
restriction, it was shockingly simple; we have to hook into a bunch of
different places, but they're all quite simple, since the structure of
the Go types still matches the structure in GraphQL.

Issue: https://github.com/Khan/genqlient/issues/30

## Test plan:
make check


Author: benjaminjkraft

Reviewers: csilvers, dnerdy, aberkan, jvoll, mahtabsabet, MiguelCastillo, StevenACoffman

Required Reviewers: 

Approved By: csilvers, dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/121
2021-09-29 17:52:06 -07:00
Ben Kraft f4c981031e Allow genqlient types to be marshaled safely (#120)
## Summary:
When genqlient generates output types, it generates whatever code is
necessary to unmarshal them.  Conversely, when it generates input types,
it generates whatever code is necessary to marshal.  This is all that's
needed for genqlient itself: it never needs to marshal output types or
unmarshal input types.

But maybe you do!  (For example, to put the responses in a cache, which
is the use case that @csilvers hit at Khan, although there are others
one can imagine.)  While we can't support every serialization format you
might want (at least not without adding plugins or some such), it's not
unreasonable to expect that since genqlient can read JSON, it can write
it too.  Sadly, in the past this was not true for types requiring custom
unmarshaling logic, for several reasons.

In this commit I implement logic to always write both marshalers and
unmarshalers whenever they're needed to be able to correctly round-trip
the types, even though genqlient doesn't do so.  I wasn't starting from
scratch, since of course we already write both marshalers and
unmarshalers in some cases.  But this ended up requiring surprisingly
large changes on the marshaling side, mostly to correctly support
embedding (which we use for named fragments).

Specifically, as the comments in `types.go` discuss, the most difficult
issue is spreads with duplicate fields, which translate to Go embedded
fields which end up hidden from the json-marshaler.  Ultimately, I had
to do things quite differently from unmarshaling, and essentially
flatten the type when we write marshaler.  But in the end it's not so
ugly -- indeed arguably it's cleaner!  Mainly it's just different.

One thing to note is that we do marshal `__typename` based on
what we know about the types; users need not fill it in (and if they
do we'll ignore it).  This seemed to me to be a better UX, and
didn't add much complexity.

In general, I begin to wonder whether using `encoding/json` at all is
really right for genqlient: we're doing a lot of work to appease it,
despite knowing what our types look like.  I think it would still be a
significant increase in lines of code to roll our own, but that code
would perhaps be simpler, and would surely be faster (although if we
just want the speed gains we could use another JSON-generator library,
see also #47).  Anyway, something to think about in the future.

## Test plan:
make tesc


Author: benjaminjkraft

Reviewers: csilvers, StevenACoffman, benjaminjkraft, dnerdy, aberkan, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: StevenACoffman, dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/120
2021-09-29 10:30:43 -07:00
Ben Kraft b84dda2612 Add clearer error text a few places (#117)
## Summary:
It's nice to be clear here because it may be your first interaction with
genqlient!

## Test plan:
make check


Author: benjaminjkraft

Reviewers: StevenACoffman, benjaminjkraft, dnerdy

Required Reviewers: 

Approved By: StevenACoffman

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/117
2021-09-28 14:56:49 -07:00
Ben Kraft 65c3e20ee6 Fix bugs relating to optional fields with custom (un)marshalers (#116)
## Summary:
There were a few bugs here, one of which Craig came across when pulling
the custom-unmarshaler change into webapp:
1. If you have an optional field with a custom unmarshaler, and the
   server omits the field from the response entirely (i.e. does not
   write `"myField": null`), we would still call your unmarshaler with
   an input of `[]byte(nil)`.  This is just wrong; it's our job to do
   the nil-check.  (This is the one Craig found; in practice gqlgen
   servers do not do this and I think the spec says not to although it's
   a bit fuzzy on the matter of serialization.  But in practice we have
   mocks that do it -- for required fields even! -- and it seems better
   to handle it than pass you data on which you'll probably err or even
   panic.)
2. If you have an optional field with a custom unmarshaler, and the
   server returns an explicit null (i.e. `"myField": null`), we would
   call your unmarshaler with `[]byte("null")`.  In principle the intent
   was you're supposed to implement that, as [`json.Unmarshaler`
   advises][1].  But (a) I forgot to document that, and (b) in practice
   `json.Unmarshal` [does *not* call you in that case][2], i.e. its
   advice is unnecessary.  So I think it's better for us to just match
   it, and not call you.  (And in that case I see no reason to bother
   documenting the advice.)
3. If you have an optional, `pointer: true` field with a custom
   marshaler, the reverse of (2) applies: if the pointer is nil, we
   shouldn't really call you.  (Indeed if you were a real
   `json.Marshaler` with a value-method rather than a pointer-method,
   trying to call you might panic!)  Note we don't need to explicitly
   write "null"; we just leave the `json.RawMessage` as nil, and
   `json.Marshal` [handles that][3].
4. We handle interface types effectively the same as custom
   unmarshalers, just we generate the unmarshaler.  So if you have an
   optional field with interface type, (1) would also apply there; our
   generated unmarshaler returns an error in this case.
5. While (2) doesn't apply to such optional interface fields (because we
   do the customary `if string(b) == "null"` check -- this I at least
   thought to test), if you set `pointer: true` on the field, we would
   still call the unmarshaler on the value, and it would no-op, but only
   *after* we initialized the pointer.  Put more simply, we'd return a
   non-nil pointer to nil interface, rather than a nil pointer; this is
   wrong since the whole point of `pointer: true` is you only get a
   non-nil pointer if your value is nil!  Of course, in practice there's
   little reason to use `pointer: true` on interface fields, and indeed
   this stuff gets so confusing my test was even wrong.

In this commit I fix all the bugs, by adding appropriate nil-checks to
wrap the unmarshaler-calls.  The templates are, as always, a bit
confusing, but the generated code makes it clear what changed.

Note we'll want to land this before cutting a release with custom
marshaler/unmarshaler support, because the first three bugs are
potentially quite noticeable.  (The latter two are in `v0.1.0`, but
presumably quite rare.)

[1]: https://pkg.go.dev/encoding/json#Unmarshaler
[2]: https://play.golang.org/p/Pw6zNN8trGO
[3]: https://play.golang.org/p/crTfnT7ePte

Issue: https://phabricator.khanacademy.org/D74453#inline-558571

## Test plan:
make tesc


Author: benjaminjkraft

Reviewers: csilvers, StevenACoffman, benjaminjkraft, aberkan, dnerdy, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: csilvers, StevenACoffman

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/116
2021-09-27 20:35:39 -07:00
Ben Kraft 7dcfa55128 [🔥AUDIT🔥] Fix tests after merge (#112)
🖍 _This is an audit!_ 🖍

## Summary:
This is what I get for not waiting for them to pass at each step of
landing a stack!

## Test plan:
make check


Author: benjaminjkraft

Auditors: dnerdy

Required Reviewers: 

Approved By: 

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14)

Pull Request URL: https://github.com/Khan/genqlient/pull/112
2021-09-24 11:24:07 -07:00
Ben Kraft 6e2b1a5811 Fix broken behavior for several options on the same node (#105)
## Summary:
Previously, we actually allowed you to put several genqlient directives
on the same node, but the semantics were undocumented (and somewhat
confusing, when it comes to `typename`).  In order to support directives
on input options, we're actually going to be encouraging this usage (see
notes in #14), so it's time to fix it.  To avoid confusion, I just had
conflicting directives be an error, rather than defining which one
"wins".  The same applies to specifying the same option several
times in one directive.

I also fixed two small bugs:
- `typename` on an operation would incorrectly cascade down to
  all input types in a query (causing conflicts).
- directive parse errors had useless positions, now they're correct

## Test plan:
make check


Author: benjaminjkraft

Reviewers: StevenACoffman, dnerdy, aberkan, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: StevenACoffman, dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/105
2021-09-24 11:16:46 -07:00
Ben Kraft 8de55d352e Add support for binding with a custom marshal/unmarshal function (#104)
## Summary:
This is useful if you want to bind to a type you don't control (or use
for other things) but need different serialization than its default.
This is a feature gqlgen has and we've found it very useful.  For
example, in webapp we want to bind `DateTime` to `time.Time`, but its
default serialization is not compatible with Python, so currently we
have to bind to a wrapper type and cast all over the place, which is
exactly the sort of boilerplate genqlient is supposed to avoid.

For unmarshaling, the implementation basically just follows the existing
support for abstract types; instead of calling our own generated
helper, we now call your specified function.  This required some
refactoring to abstract the handling of custom unmarshalers generally
from abstract types specifically, and to wire in not only the
unmarshaler-name but also the `generator` (in order to compute the right
import alias).

For marshaling, I had to implement all that stuff over again; it's
mostly parallel to unmarshaling (and I made a few minor changes to
unmarshaling to make the two more parallel).  Luckily, after #103 I at
least only had to do it once, rather than implementing the same
functionality for arguments and for input-type fields.  It was still
quite a bit of code; I didn't try to be quite as completionist about the
tests as with unmarshal but still had to add a few.

Issue: https://github.com/Khan/genqlient/issues/38

## Test plan:
make check


Author: benjaminjkraft

Reviewers: StevenACoffman, dnerdy, benjaminjkraft, aberkan, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: StevenACoffman, dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/104
2021-09-24 11:16:01 -07:00
Ben Kraft 5995653583 Refactor argument-handling to use a struct (#103)
## Summary:
In this commit I refactor the argument-generation logic to move most of
the code out of the template and into the type-generator.  This logic
predates #51, and I didn't think to update it there, but I think it
benefits from similar treatment, for similar reasons.

Specifically, the main change is to treat variables as another struct
type we can generate, rather than handling them inline as a
`map[string]interface{}`.  Users still pass them the same way, but
instead of putting them into a `map[string]interface{}` and JSONifying
that, we generate a struct and put them there.

This turns out to simplify things quite a lot, because we already have a
lot of code to generate types.  Notably, the omitempty code goes from a
dozen lines to basically two, and fixes a bug (#43) in the process,
because now that we have a struct, `json.Marshal` will do our work for
us! (And, once we have syntax for it (#14), we'll be able to handle
field-level omitempty basically for free.)  More importantly, it will
simplify custom marshalers (#38, forthcoming) significantly, since we do
all that logic at the containing-struct level, but will need to apply it
to arguments.

It does require two breaking changes:

1. For folks implementing the `graphql.Client` API (rather than just
   calling `NewClient`): we now pass them variables as an `interface{}`
   rather than a `map[string]interface{}`.  For most callers, including
   Khan/webapp, this is basically a one-line change to the signature of
   their `MakeRequest`, and it should be a lot more future-proof.
2. genqlient's handling of the `omitempty` option has changed to match
   that of `encoding/json`, in particular it now never considers structs
   "empty".  The difference was never intentional (I just didn't realize
   that behavior of `encoding/json`); arguably our behavior was more
   useful but I think that's outweighed by the value of consistency with
   `encoding/json` as well as the simpler and more correct
   implementation (fixing #43 is actually quite nontrivial otherwise).
   Once we have custom unmarshaler support (#38), users will be able to
   map a zero value to JSON null if they wish, which is mostly if not
   entirely equivalent for GraphQL's purposes.

Issue: https://github.com/Khan/genqlient/issues/38
Issue: https://github.com/Khan/genqlient/issues/43

## Test plan:
make check

Author: benjaminjkraft

Reviewers: StevenACoffman, dnerdy, aberkan, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: StevenACoffman, dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14)

Pull Request URL: https://github.com/Khan/genqlient/pull/103
2021-09-22 17:16:36 -07:00
Ben Kraft ab1aaed845 Fix a bug in type-name collapsing introduced by #71 (#110)
## Summary:
We typically name our types `OperationFieldTypeFieldType`, but if a
type's name matches the preceding field-name, we omit the type-name.
In #71 I changed the behavior such that we no longer do that in the case
where the type's name matches some suffix of the name-so-far that's
longer than just the leaf field-name.

This was semi-intentional; I assumed it didn't matter and would be more
predictable this way.  But it turns out that was a feature, both in the
sense that almost any change to the type-name-generator is breaking, and
in the sense that it made the names uglier.  Plus, now that we have
better conflict-detection (#94), the possibility that some tricksy
type-names could cause problems is no longer as much of an issue, so we
can be a little less careful here.  (Although I think this is no less
safe than before; the field-names are the important part.)  So in this
commit I revert the change.

Specifically, this comes up a lot at Khan where we do
```
mutation ForcePhantom {
    forcePhantom {     # type: ForcePhantom
        error { ... }  # type: ForcePhantomError
    }
}
```
Before #71, and again after this change, we'll generate
`ForcePhantomForcePhantomError` for `error`; before we'd generate
`ForcePhantomForcePhantomErrorForcePhantomError`.

Issue: https://github.com/Khan/genqlient/issues/109

## Test plan:
make tesc


Author: benjaminjkraft

Reviewers: csilvers, aberkan, dnerdy, jvoll, mahtabsabet, MiguelCastillo, StevenACoffman

Required Reviewers: 

Approved By: csilvers

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/110
2021-09-22 17:00:27 -07:00
Ben Kraft f72933fa0e Refactor import-loading to simplify the type-generation code (#101)
## Summary:
genqlient has some code (`imports.go`) dedicated to tracking which
imports we need and avoiding conflicts, as well as converting a
(restricted) Go expression like `map[string]github.com/me/mypkg.MyType`
to an import (`github.com/me/mypkg`) and a type-reference
(`map[string]mypkg.MyType`) to be used in the context of that import,
and at least making some attempt to track conflicts.  (Right now the
conflict-avoidance is not very smart, and not very well tested, but it
comes up rarely anyway.)  Sadly, that code was a bit cumbersome to use,
because you had to first register the imports (typically from
`convert.go`), then use them (often from the template).

In this commit I refactor the order we write things in order to allow a
significant simplification of how we import; in particular we no longer
have to guess in advance what imports which template will need; it can
just do `{{ref <expr>}}` as before, and it just works.  To do this, I:
- changed the importer to have only one API, which adds the import if
  needed, and returns the reference either way
- added a check that we don't add imports after they're written
- reorganized the toplevel templates a bit to make sure that check never
  fires; we now generate all the types and operations, then write the
  imports and glue it all together
This removes a bunch of silly code, and should simplify the process of
adding custom (un)marshalers (#38).

While I was at it, I put the documentation of what expressions we
support in a more visible place, and added a type-assertion that your
custom context type implements context.Context (if applicable).

## Test plan:
make check


Author: benjaminjkraft

Reviewers: StevenACoffman, dnerdy, aberkan, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: StevenACoffman, dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/101
2021-09-16 18:09:32 -07:00
Ben Kraft 50b2f56a4e [🔥AUDIT🔥] Typo fix (#100)
🖍 _This is an audit!_ 🖍

Auditors: StevenACoffman

Author: benjaminjkraft

Required Reviewers: 

Approved By: 

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/100
2021-09-16 09:11:00 -07:00
Ben Kraft fcae8dd1d7 Add support for specifying type-names, and conflict-detection (#94)
## Summary:
In this commit I add two related features to genqlient:
conflict-detection to avoid generating two distinct types with the same
name, and an option to specify the type-name genqlient should use for
some type.

The conflict-detection was pretty simple once I realized I had already
written all the code to do it in #70.  There was a bunch of wiring,
since we now need to keep track of the GraphQL type/selection-set that
each type corresponds to, but it was pretty straightforward.  This
allows us to:
- detect and reject if you have really sneaky type-names (there are some
  examples documented in `names.go`)
- more clearly crash if genqlient accidentally generates two conflicting
  types, and
- avoid stack-overflow when handing recursive (input) types (although
  sadly the poor support for options on input types (#14) makes them
  difficult to use in many cases; you really need to be able to set
  `pointer: true`)

And with that all set up, the type-naming was also easy!  (It doesn't
have to get into the core of the type-generator, just plug in where we
choose names.  The desire for conflict detection was the main reason I
hadn't set it up already.)  Note that the existing limitation of #70 that
the fields have to be in exactly the same order remains (and is now
documented as #93); it's not deeply hard to fix but it's surprisingly
much work.

Issue: https://github.com/Khan/genqlient/issues/60
Issue: https://github.com/Khan/genqlient/issues/12

## Test plan:
make check


Author: benjaminjkraft

Reviewers: StevenACoffman, jvoll, benjaminjkraft, aberkan, csilvers, dnerdy, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: StevenACoffman, jvoll

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/94
2021-09-15 18:06:43 -07:00
Ben Kraft 5211442843 Add a new option to treat an interface like an object (#97)
## Summary:
The basic idea here is if you only request interface fields (no
fragments) you may not care about the concrete type, and so we could
just generate a struct as if it were an object.  I don't think it's a
good idea to do that by default, because then if you later add a
fragment all your code totally changes, but it's quite reasonable as an
option!

Most of the code involved is just wiring and validation; the
core implementation is literally just: treat it like an object.

Issue: https://github.com/Khan/genqlient/issues/85

## Test plan:
make check


Author: benjaminjkraft

Reviewers: csilvers, StevenACoffman, benjaminjkraft, aberkan, dnerdy, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: StevenACoffman

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/97
2021-09-15 18:00:22 -07:00
Ben Kraft ce079a7e16 Clean up example a little (#89)
## Summary:
I realized:
- it's simpler to avoid the usual `cmd` and just put it all in the same
  directory
- we don't need schema.json since GitHub now posts a schema in SDL
  format

## Test plan:
make lint example


Author: benjaminjkraft

Reviewers: dnerdy, StevenACoffman, aberkan, jvoll, mahtabsabet, MiguelCastillo

Required Reviewers: 

Approved By: dnerdy, StevenACoffman

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/89
2021-09-15 10:48:50 -07:00
Steve Coffman 673840e495 Picking some nits that my IDE complained about (#91)
* Picking some nits that my IDE complained about

Signed-off-by: Steve Coffman <steve@khanacademy.org>

* Update graphql/util.go

Co-authored-by: Ben Kraft <benkraft@khanacademy.org>

* revert to original for comment

Signed-off-by: Steve Coffman <steve@khanacademy.org>

Co-authored-by: Ben Kraft <benkraft@khanacademy.org>
2021-09-14 13:42:47 -04:00
Ben Kraft 639b46df32 Avoid putting incorrect extensions on error snapshot files (#92)
## Summary:
They were accidentally ending up as `.go` or `.graphql`, but are
actually just text.

Issue: https://github.com/Khan/genqlient/issues/90

## Test plan:
make check


Author: benjaminjkraft

Reviewers: StevenACoffman, dnerdy

Required Reviewers: 

Approved By: StevenACoffman

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/92
2021-09-14 10:30:33 -07:00
Ben Kraft 2eba9a2c30 Reorganize documentation to make room to grow (#84)
## Summary:
In this commit I reorganize much of our documentation into a new `docs`
directory, where there will hopefully be more room to grow and to
organize things in a user-friendly way.  There's almost no net-new
documentation, although of course it's a great time to review it anyway.

In particular:
- I moved the documentation for the `genqlient.yaml` config file into an
  example file instead of GoDoc (which now just points to the example
  file); I think this will be a lot clearer for casual users.
- I moved the documentation for the `@genqlient` directive out of GoDoc
  and into a GraphQL schema file (since while it's a comment it's all
  real syntax), likewise, and made the `GenqlientDirective` type private
  (since there's now nothing useful to do with it).
- I moved `DESIGN.md` and the logo into `docs/` (just to keep the
  toplevel a bit cleaner), and separated the Contributing section of the
  README into `docs/CONTRIBUTING.md` (which github will automatically
  link on various issue and PR pages).

This leaves it so that:
- README.md is the only documentation at the toplevel (and will become
  just the high-level introduction as I add more user docs to `docs/`)
- GoDoc is only documentation for if you want to call genqlient
  programmatically (which is fairly limited as the API surface is quite
  small: it's now just Main, Generate, and Config, plus a constructor, a
  single method, and a bunch of fields on the latter)

In future commits, I'll add some more new documentation to the `docs`
directory.

Issue: https://github.com/Khan/genqlient/issues/26

## Test plan:
make check (and read the docs)


Author: benjaminjkraft

Reviewers: jvoll, benjaminjkraft, aberkan, dnerdy, MiguelCastillo, mahtabsabet

Required Reviewers: 

Approved By: jvoll

Checks:  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/84
2021-09-10 16:03:30 -07:00
Ben Kraft d41cf636af Clean up godoc (#82)
## Summary:
Before open-sourcing, we want to make sure that (a) GoDoc looks
reasonable, and (b) everything in the API is something we want to commit
to.  In this commit, I do some miscellaneous cleanup on both fronts;
this does involve a few breaking changes to the programmatic API (better
now than once it has users).  In future commits, I'll likely move the
documentation for `genqlient.yaml` and `@genqlient` to clearer places,
and make `GenqlientDirective` private, such that GoDoc is really only
for programmatic users.

Fixes #25.

Issue: https://github.com/Khan/genqlient/issues/25

## Test plan:
make check


Author: benjaminjkraft

Reviewers: dnerdy, benjaminjkraft, jvoll, aberkan, MiguelCastillo, mahtabsabet

Required Reviewers: 

Approved By: dnerdy, jvoll

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/82
2021-09-10 15:54:34 -07:00
Ben Kraft dc38360d9d Add a flag --init to write a default config (#81)
## Summary:
Steve pointed out (#73) that having genqlient with no arguments silently
use a default config file was a bit confusing, and changed it to use
`genqlient.yaml` by default (#74).  Mark pointed out (#76) that this
makes it a bit less convenient when you're starting from scratch; you
have to go create a config file.  In this commit I add a new init flag
that creates you a config file before using it.

Originally the suggestion was to use subcommands, e.g. we'd have
`genqlient init` and `genqlient generate` and so on.  But I couldn't
think of anything else we might want subcommands for in the future, and
it felt a little silly to make you type `generate` each time.  So
instead, I made it a flag, which has the nice property that you can do
`genqlient --init` and it will generate and then use a config file.  (I
mean, maybe it will immediately crash because you don't have a schema,
but hopefully that's still a useful clue as to what to do next!)  The
implmentation was fairly trivial.

Since we now have a nice way to generate a default config, I removed the
default values for most of the options; I've always felt they were
probably more confusing than helpful.  (And indeed, all the users I know
of (Khan/webapp, and the much smaller project Steve was working on, are
setting those options explicitly.)  This required a slight change to
the syntax to say "don't use context", which is probably also net clearer.

I decided this is also a good time to pull in a proper CLI parser (#31);
see ADR-504 for more on that choice.  This also adds some nice help
messages!

Fixes #76, #31.

Issue: https://github.com/Khan/genqlient/issues/76

## Test plan:
```
go run .
go run . --init
go run . --init example/genqlient.yaml     # refuses to clobber
go run . --init example/newgenqlient.yaml
```


Author: benjaminjkraft

Reviewers: dnerdy, aberkan, MiguelCastillo, StevenACoffman

Required Reviewers: 

Approved By: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/81
2021-09-10 15:49:54 -07:00
Ben Kraft e88305ecbd Add support for abstract-typed named fragments (#79)
## Summary:
In previous commits I added support to genqlient for interfaces,
inline fragments, and, most recently, named fragments of concrete
(object) type.  This leaves only named fragments of interface type!
Like other named fragments, these are useful for code-sharing,
especially if you want some code that can handle the same fields of
several different types.

As seems to be inevitable with genqlient, this was mostly pretty
straightforward, although there turned out to be surprisingly many
places we needed to add some handling; almost anywhere that touches
interfaces *or* named fragments needed some updates.  But it's all
hopefully fairly clear code.

As a part of this change I made three semi-related improvements:
1. I refactored the handling of descriptions (i.e. GoDoc), because it
   was getting more and more confusing and duplicative.  I'm still not
   sure how much of it it makes sense to inline vs. separate, but I
   think this is better than it was.  This resulted in some minor
   changes to descriptions, generally in the direction of making things
   more consistent.
2. I bumped the minimum Go version to 1.14 so we can guarantee support
   for duplicate interface methods.  These are useful for
   abstract-in-absstract spreads; we generate an interface for the
   fragment, and (if the fragment-type implements the scope-type) we
   embed it into the interface we generate for its spread-context, and
   if the two have a duplicated field we thus duplicate the method.  It
   wouldn't be impossible to support this on 1.13 (maybe just by
   omitting said embed) but it didn't seem worth it.  This also removes
   a few special-cases in tests.
3. I added a bunch of code to better format syntax errors in the
   generated code (which we see from `gofmt`).  This is mostly just an
   internal improvement; I wrote it because I got annoyed while hunting
   down a few such errors..

Fixes, at last, #8.

Issue: https://github.com/Khan/genqlient/issues/8

## Test plan:
make check


Author: benjaminjkraft

Reviewers: dnerdy, benjaminjkraft, aberkan, MiguelCastillo

Required Reviewers: 

Approved By: dnerdy

Checks:  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/79
2021-09-09 09:48:18 -07:00
Ben Kraft f99c10d6fd Add support for concrete-typed named fragments (#75)
## Summary:
In previous commits I added support to genqlient for interfaces and
inline fragments.  This means the only query structures that remain are
named fragments and their spreads, e.g.
```
fragment MyFragment on MyType { myField }
query MyQuery { getMyType { ...MyFragment } }
```
Other than mere completionism, these are potentially useful for code
sharing: you can spread the same fragment multiple places; and then
genqlient can notice that and generate the same type for each.  (They
can even be shared between different queries in the same package.)

In this commit I add support for named fragments of concrete
(object/struct, not interface) type, spread into either concrete or
abstract scope.  For genqlient's purposes, these are a new "root"
type-name, just like each operation, and are then embedded into the
appropriate struct.  (Using embeds allows their fields to be referenced
as fields of the containing type, if convenient.  Further design
considerations are discussed in DESIGN.md.)

This requires new code in two main places (plus miscellaneous glue),
both nontrivial but neither particularly complex:
- We need to actually traverse both structures and generate the types
  (in `convert.go`).
- We need to decide which fragments from this package to send to the
  server, both for good hyigene and because GraphQL requires we send
  only ones this query uses (in `generate.go`).
- We need a little new wiring for options -- because fragments can be
  shared between queries they get their own toplevel options, rather
  than inheriting the query's options.

Finally, this required slightly subtler changes to how we do
unmarshaling (in `types.go` and `unmarshal.go.tmpl`).  Basically,
because embedded fields' methods, including `UnmarshalJSON`, get
promoted to the parent type, and because the JSON library ignores their
fields when shadowed by those of the parent type, we need a little bit
of special logic in each such parent type to do its own unmarshal and
then delegate to each embed.  This is similar (and much simpler) to
what we did for interfaces, although it required some changes to the
"method-hiding" trick (used for both).  It's only really necessary in
certain specific cases (namely when an embedded type has an
`UnmarshalJSON` method or a field with the same name as the embedder),
but it's easier to just generate it always.  This is all described in
more detail inline.

This does not support fragments of abstract type, which have their own
complexities.  I'll address those, which are now the only remaining
piece of #8, in a future commit.

Issue: https://github.com/Khan/genqlient/issues/8

## Test plan:
make check


Author: benjaminjkraft

Reviewers: dnerdy, benjaminjkraft, aberkan, MiguelCastillo

Required Reviewers: 

Approved By: dnerdy

Checks:  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/75
2021-09-09 09:39:30 -07:00
Ben Kraft 6c86eed770 Clean up, test, and document ContextType and ClientGetter options (#77)
## Summary:
ContextType is in use at Khan as a part of our ka-context system; it
basically just lets you configure the type to pass as the `ctx` argument
to genqlient helpers (or say to omit such an argument).  ClientGetter I
wrote thinking we might use it; then we didn't (because we have a few
different clients we may use) but it's not much code and may be helpful
to others.  In this commit I clean up, document, and add tests for both
options.

The cleanup is mainly for ClientGetter, which was kind of broken before
because it was a Go snippet but couldn't specify imports.  I was
thinking maybe you want to be able to write `ctx.Something()`, but I
just don't see how to make it work, so I made it a function of context,
which is probably the better idea anyway.

Additionally, I improved the documentation for both, and added tests for
those and several other config options that weren't completely tested.

Fixes #5.

Issue: https://github.com/Khan/genqlient/issues/5

## Test plan:
make check


Author: benjaminjkraft

Reviewers: dnerdy, aberkan, MiguelCastillo

Required Reviewers: 

Approved By: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull Request URL: https://github.com/Khan/genqlient/pull/77
2021-09-07 09:58:49 -07:00
Steve Coffman f3e601353c Add IDEs to gitignore and default config file name (#74)
Signed-off-by: Steve Coffman <steve@khanacademy.org>
2021-09-02 21:00:29 -04:00
Ben Kraft 6fdb170b99 Fix type-naming in the presence of interfaces, and refactor it a lot (#71)
## Summary:
When adding support for interfaces, I did not do the type-names as I
intended: they came out to be `MyFieldMyType`, not
`MyInterfaceMyFieldMyType`, which is inconsistent, but not strictly
wrong.  But once supporting fragments, this is also now incorrect.
(Exactly why is described in the comments inline.)  In this commit, in
any case, I fix it.

To do that, I finally did the last of the refactors I've been hoping to
do but unable to successfully implement, which is to make the type-name
and type-name-prefix management clearer.  In the past it was kind of
spread out, and each caller would have to pass the right name into
`convertDefinition`, which go quite unwieldy.  Now, the case that really
wanted that -- the operation toplevel -- just does it own thing; and the
main name-generation code  is factored out into a separate file with
tests, and with a long comment that goes into all the details of the
algorithm that the design-doc didn't cover.  (I even had some fun using
a linked list to implement the prefix-stack!)

This allowed me to fix the above bug fairly easily -- actually the fix
was pretty much automatic once I understood how to organize things.
There is one change which is that if your query name is unexported, we
no longer do the same with the input-type names; it's unclear to me if
anyone will actually care about this behavior (Khan always makes the
queries exported) but if they did it was very inconsistent (only at the
query toplevel, and only for input-objects, not enums), so we can
reimplement it properly if that comes up.  As a bonus fix, we now better
handle the case where your type-names are lowercase, which is legal if
nonstandard GraphQL.

Issue: https://github.com/Khan/genqlient/issues/8

## Test plan:
make tesc


Author: benjaminjkraft

Reviewers: dnerdy, benjaminjkraft, aberkan, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/71
2021-08-30 10:50:11 -07:00
Ben Kraft 95609f77a1 If requested, validate binding-types get the right fields (#70)
## Summary:
One sharp edge of the new `bindings` setting (when used for composite
types) is this: the (presumably struct) type to which you're binding
may expect to have particular fields, but it's GraphQL so you could have
requested some other set of fields.  Now, if you ask us, we check.

Specifically, I've added a new setting under the `bindings` items, which
says: everywhere we query this must select these fields.  (Or use its
own inline `# @genqlient(bind: ...)`.)  It must select exactly those
fields, in order, no more, no less.  This was fairly easy to implement;
actually comparing the selections was surprisingly much code but it's
all pretty straightforward.

## Test plan:
make check


Author: benjaminjkraft

Reviewers: dnerdy, aberkan, csilvers, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/70
2021-08-30 10:18:52 -07:00
Ben Kraft fc4aa084ae [🔥AUDIT🔥] Fix snapshots from changes to __typename error (#72)
🖍 _This is an audit!_ 🖍

## Summary:
These got broken by the merge.

## Test plan:
make check


Author: benjaminjkraft

Auditors: aberkan, csilvers, dnerdy, MiguelCastillo

Required Reviewers: 

Approved by: 

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/72
2021-08-27 18:20:17 -07:00
Ben Kraft 46898ca52c Return clearer errors when __typename is missing (#68)
## Summary:
In practice, at Khan at least, this is easy to mess up when writing
mocks, because you write the mock by looking at the query, and the query
doesn't say it's asking for `__typename` (because genqlient
automatically adds that).  A sufficiently-smart mocking library might be
able to fix that, or detect it at least, but in any case, we can give a
clearer error.

I also removed an unrelated TODO that was done.

Issue: https://khanacademy.slack.com/archives/C01120CNCS0/p1630019788014000

## Test plan:
make check


Author: benjaminjkraft

Reviewers: dnerdy, aberkan, csilvers, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/68
2021-08-27 18:12:35 -07:00
Ben Kraft e6b1984d44 Add support for inline fragments (#65)
## Summary:
In this commit I add support for inline fragments
(`... on MyType { fields }`) to genqlient.  This will make interfaces a
lot more useful!  In future commits I'll add named fragments, for which
we'll generate slightly different types, as discussed in DESIGN.md.

In general, implementing the flattening approach described in DESIGN.md
was... surprisingly easy.  All we have to do is recurse on applicable
fragments when generating our selection-set.  The refactor to
selection-set handling this encouraged was, I think, quite beneficial.
It did reveal two tricky pre-existing issues.

One issue is that GraphQL allows for duplicate selections, as long as
they match.  (In practice, this is only useful in the context of
fragments, although GraphQL allows it even without.) I decided to handle
the simple case (duplicate leaf fields; we just deduplicate) but leave
to the future the complex cases where we need to merge different
sub-selections (now #64).  For now we just forbid that; we can see how
much it comes up.

The other issue is that we are generating type-names incorrectly for
interface types; I had intended to do `MyInterfaceMyFieldMyType` for
shared fields and `MyImplMyFieldMyType` for non-shared ones, but instead
I did `MyFieldMyType`, which is inconsistent already and can result in
conflicts in the presence of fragments.  I'm going to fix this in a
separate commit, though, because it's going to require some refactoring
and is irrelevant to the main logic of this commit; I left some TODOs in
the tests related to this.

Issue: https://github.com/Khan/genqlient/issues/8

## Test plan:
make check


Author: benjaminjkraft

Reviewers: dnerdy, aberkan, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/65
2021-08-27 18:06:30 -07:00
Ben Kraft 222d6f191a Document and improve support for binding non-scalars to a specific type (#69)
## Summary:
We had this setting called "scalars", which said: bind this GraphQL type
to this Go type, rather than the one you would normally use.  It's
called that because it's most useful for custom scalars, where "the one
you would normally use" is "error: unknown scalar".  But nothing ever
stopped you from using it for a non-scalar type.  I was planning on
removing this functionality, because it's sort of a rough edge, but a
discussion with Craig found some good use cases, so instead, in this
commit, I document it better and add some slightly nicer ways to specify
it.

Specifically, here are a few potential non-scalar use cases:
- bind a GraphQL enum to a nonstandard type (or even `string`)
- bind an input type to some type that has exactly the fields you want;
  this acts as a sort of workaround for issues #14 and #44
- bind an object type to your own struct, so as to add methods to it
  (this is the use case Craig raised)
- bind an object type to your own struct, so as to share it between
  multiple queries (I believe named fragments will address this case
  better, but it doesn't hurt to have options)
- bind a GraphQL list type to a non-slice type in Go (presumably one
  with an UnmarshalJSON method), or any other different structure
The latter three cases still have the sharp edge I was originally
worried about, which is that nothing guarantees that the fields you
request in the query are the ones the type expects to get.  But I think
it's worth having the option, with appropriate disclaimers.

The main change to help support that better is that you can now specify
the type inline in the query, as an alternative to specifying it in the
config file; this means you might map a given object to a given struct,
but only in some cases, and when you do you have a chance to look at the
list of fields you're requesting.

Additionally, I renamed the config field from "scalars" to "bindings"
(but mentioned it in a few places where you might go looking for how to
map scalars, most importantly the error message you get for an unknown
(custom) scalar).  While I was making a breaking change, I also changed
it to be a `map[string]<struct>` instead of a `map[string]string`,
because I expect to add more fields soon, e.g. to handle issue #38.

Finally, since the feature is now intended/documented, I added some
tests, although it's honestly quite simple on the genqlient side.

## Test plan:
make tesc


Author: benjaminjkraft

Reviewers: csilvers, aberkan, dnerdy, MiguelCastillo

Required Reviewers: 

Approved by: csilvers

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/69
2021-08-27 15:57:10 -07:00
Ben Kraft bf266d874d [🔥AUDIT🔥] Mark interfaces as enabled! (#67)
🖍 _This is an audit!_ 🖍

## Summary:
We've completed support for interfaces!  Fragments are still pending,
but interfaces by themselves should be usable.  But I forgot to actually
remove the flag they were behind.  In this commit I do!

Issue: https://khanacademy.slack.com/archives/C01120CNCS0/p1630012808004100

## Test plan:
make check


Author: benjaminjkraft

Auditors: aberkan, csilvers, dnerdy, MiguelCastillo

Required Reviewers: 

Approved by: 

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/67
2021-08-26 14:35:54 -07:00
Ben Kraft 8f9d1cf792 Add support for interfaces, part 4: getter methods (#57)
## Summary:
Right now, if you make a query like `{ myInterface { field } }`, you
have to type-switch on all the possible implementations of `myInterface`
to get at `field`.  Now, we generate getter-methods (e.g. `GetField`),
to make that access easier.  Of course this only applies to shared
fields (which for now are the only ones, but once we support fragments
will no longer be).

This also includes a small change to the way we generate type-names for
interfaces: we no longer include the name of the concrete type in the
interface we propagate forward, so we generate
`MyInterfaceMyFieldMyType`, not `MyInterfaceMyImplMyFieldMyType`, in the
case where you have an interface `MyInterface` implemented by `MyImpl`
(and maybe other types) with field `myField: MyType`.  This is necessary
so the getter method returns a well-defined type, and also probably
convenient for calling code.  It will have to get a little bit more
complicated once we support fragments, where you could have two
implementing types with identically-named fields of different types, but
I think it'll be easiest to figure out how to deal with that when
implementing fragments.

While I was in the area, I added to the interface doc-comment a list of
the implementations.  (In GraphQL, we're guaranteed to know them all
assuming our schema is up to date.)

Issue: https://github.com/Khan/genqlient/issues/8

## Test plan:
make check


Author: benjaminjkraft

Reviewers: benjaminjkraft, dnerdy, aberkan, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/57
2021-08-25 12:02:18 -07:00
Ben Kraft 65f9e90f2b Add support for interfaces, part 3: automatically add __typename (#56)
## Summary:
In #52, I added support for interface types, but with the simplifying
restriction (among others) that the user must request the field
`__typename`.  In this commit, I remove this restriction.

The basic idea is simple: we preprocess the query to add `__typename`.
The implementation isn't much more complicated!  Although it required
some new wiring in a few places.

Issue: https://github.com/Khan/genqlient/issues/8

## Test plan:
make check


Author: benjaminjkraft

Reviewers: dnerdy, aberkan, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/56
2021-08-25 11:59:45 -07:00
Ben Kraft 1e87553788 Add support for interfaces, part 2: list-of-interface (#54)
## Summary:
In this commit I remove one of the limitations of our support for
interfaces, from #52, by adding support for list-of-interface fields.
This was surprisingly complex!  The issue is that, as before, it's the
containing type that has to do all the glue work -- and it's that glue
work that is complicated by list-of-interface fields.

All in all, it's not that much new code, and by far the hard part is
just 20 lines in the UnmarshalJSON template (which come with almost
twice as many lines of comments to explain them).  It may be easiest to
start by reading some of the generated code, and then read the template.

I also added support for such fields with `pointer: true` specified,
such that the type is `[][]...[]*MyInterface`, although I don't know why
you would want that.  This does *not* allow e.g. `*[]*[][]*MyInterface`;
that would require a way to specify it (see #16) but also add some extra
complexity (as we'd have to actually walk the type-unwrap chain
properly, instead of just counting the number of slices and whether
there's a pointer).

Issue: https://github.com/Khan/genqlient/issues/8

## Test plan:
make check


Author: benjaminjkraft

Reviewers: dnerdy, benjaminjkraft, aberkan, csilvers, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13)

Pull request URL: https://github.com/Khan/genqlient/pull/54
2021-08-25 11:57:24 -07:00
Ben Kraft 4c38cb7759 Add support for interfaces, part 1: the simplest cases (#52)
## Summary:
In this commit I begin the journey to add the long-awaited support for
interfaces (part of #8).  Well, it's not the beginning: I already had
some half-written broken code around.  But it's the first fully
functional support, and especially, the first *tested* support; it's
probably best to review the nontrivially-changed code as if it were new.

Conceptually, the code so far is pretty simple: we generate an interface
type, and the implementations.  (That code is in fact mostly unchanged.)
The complexity comes in because encoding/json doesn't know how to
unmarshal that.  So we have to add an UnmarshalJSON method, which
actually has to be on the types with interface-type fields, that knows
how.  I factored it into two methods, such that that UnmarshalJSON
method is just glue, and then there's a separate function, corresponding
to each interface-type, that actually does all the work.  (If only one
could just write it as an actual method!)  The method uses the same
trick suggested to me by a few others in another context to deserialize
all but one field, then handle that field specially, which is discussed
in the code.

This still has some limitations, which will be lifted in future commits:
- it doesn't allow for list-of-interface fields
- it requires that you manually ask for `__typename`
- it doesn't support fragments, i.e. you can only query for interface
  fields, not concrete-type-specific ones
But it works, even in integration tests, which is progress!

As a part of this, I added a proper config option for the "allow broken
features" flag, since I need to be able to set it from the integration
tests which are in a separate package (and actually shell out via `go
generate`).  I also renamed what was to be the first case
(InterfaceNoFragments), and replaced it with a further-simplified
version (avoiding list-of-interface fields.

[1] https://github.com/benjaminjkraft/notes/blob/master/go-json-interfaces.md

Issue: https://github.com/Khan/genqlient/issues/8

## Test plan:
make tesc

Author: benjaminjkraft

Reviewers: dnerdy, benjaminjkraft, aberkan, csilvers, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/52
2021-08-25 11:51:26 -07:00
Ben Kraft 8815d0991c Big refactor to separate operation-traversal from code-generation (#51)
## Summary:
I've felt for a while that types.go is way too confusing, and as I
started to implement some of the more complex cases of generating
interface-types, the cracks were really starting to show.  Luckily, I
also finally realized how to fix it: we need to separate the process of
traversing the GraphQL operation and schema to decide what types to
generate from the process of actually generating those types.  This
requires an extra set of intermediate data structures, but I think it
makes things quite a lot easier to understand -- and, importantly, it
means that the code-generation doesn't need to go in the order we
traverse the query/schema.

So in this commit, I did that huge refactor.  It's probably best to just
review types.go and traverse.go as if they were new; the old code was
quite hard to understand and the new code will hopefully make a lot more
sense.  (And to that end, review comments about what could be organized
better or needs more documentation are very much in order, even for code
that is mostly unchanged.)

This does introduce one bug, sort of, which is that rather than
generating broken code for list-of-interface fields, we generate no code
at all.  (A TODO in unmarshal.go describes why.)  I'll fix this when I
add support for those fields.  (It's all behind the AllowBrokenFeatures
flag, anyway.)  Otherwise, the only changes to generated code are that a
few methods are ordered differently, because we now generate the
implements-interface methods with the interface, rather than the
implementations, as it's much simpler that way.  (In GraphQL, unlike Go,
we know the list of all possible implementations of each interface, so
this is possible.)

## Test plan:
golangci-lint run ./... && go test ./...

Author: benjaminjkraft

Reviewers: dnerdy, benjaminjkraft, aberkan, csilvers, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/51
2021-08-25 11:49:30 -07:00
Ben Kraft 6689d5a009 Use yaml.UnmarshalStrict (#55)
## Summary:
As Mark pointed out in a review where I realized that the *example* had
a bogus config key (which I hadn't noticed earlier because it was just
using the default value), we should probably do a strict-unmarshal;
there's no reason you should have random extra keys in your config and
if you do it's probably a mistake.  (Or maybe you're running a too-old
version of genqlient for your codebase, which you probably also want to
know.)  Now we do.

## Test plan:
- `make check`
- in webapp, `go mod edit -replace github.com/Khan/genqlient=../genqlient`
  then `make genqlient` produces no diffs (except go.mod/go.sum).


Author: benjaminjkraft

Reviewers: dnerdy, aberkan, csilvers, MiguelCastillo

Required Reviewers: 

Approved by: dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/55
2021-08-23 15:52:08 -07:00
Ben Kraft 3746ecd063 Add integration tests against a gqlgen server (#50)
## Summary:
We have lots of tests covering codegen, but not a lot that actually run
the code.  For things where all we do is generate types, that's (mostly)
fine (especially now that we actually build the code), but as we
generate more nontrivial non-type code we need to actually run it.

So I wrote some integration tests that spin up a little gqlgen
server, and make calls to it; we can add more over time especially as
the JSON marshalling logic gets complex (to support fragments).
They're more work to write than the snapshot tests, but of course they
can test a lot more.

In addition to gqlgen, I pulled in testify assert/require, because I
really wanted to be able to use assert.Equal and such for these.  I
didn't bother converting existing tests, although I assume they will
become useful elsewhere in time.  Both gqlgen and testify are of course
only used in tests.

Fixes #21 and #24.
Issue: https://github.com/Khan/genqlient/issues/21
Issue: https://github.com/Khan/genqlient/issues/24

## Test plan:
make check

Author: benjaminjkraft

Reviewers: aberkan, dnerdy, benjaminjkraft, csilvers, MiguelCastillo

Required Reviewers: 

Approved by: aberkan, dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/50
2021-08-20 10:54:41 -07:00
Ben Kraft 700392315a Enable golangci-lint (#49)
## Summary:
It would be nice to have some linting beyond `go vet`!  Now we do.  I
started by copying the config from Khan/webapp.  I did remove a couple
of staticcheck checks that I didn't feel were useful.  (Note also that
exportloopref is the replacement for scopelint in newer golangci-lint.)

Included are all the needed lint fixes; most are stylistic but the
changes in the example are a (minor) bugfix.

Fixes #22.
Issue: https://github.com/Khan/genqlient/issues/22

## Test plan:
make check

Author: benjaminjkraft

Reviewers: aberkan, dnerdy, benjaminjkraft, csilvers, MiguelCastillo

Required Reviewers: 

Approved by: aberkan, dnerdy

Checks:  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint,  Test (1.17),  Test (1.16),  Test (1.15),  Test (1.14),  Test (1.13),  Lint

Pull request URL: https://github.com/Khan/genqlient/pull/49
2021-08-20 10:39:12 -07:00
Ben Kraft dfc9f02efc Actually build the generated code in tests
This revealed one bug already (a redux of #43)!  And will hopefully help
more as unmarshalers get more complicated (thanks to
interfaces/fragments).
2021-06-03 15:48:05 -07:00
Ben Kraft 1f442da041 Switch to cupaloy for snapshots
Slightly uglier filenames, but less code and free diffing!  Approved in
ADR-466 for Khan use.  Fixes #23.
2021-06-03 12:08:56 -07:00