Ben KraftandGitHub
8de55d352e
## 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
34 lines
1015 B
Cheetah
34 lines
1015 B
Cheetah
{{/* (the blank lines at the start are intentional, to separate
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the helper from the function it follows) */}}
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func __unmarshal{{.GoName}}(b []byte, v *{{.GoName}}) error {
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if string(b) == "null" {
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return nil
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}
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var tn struct {
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TypeName string `json:"__typename"`
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}
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err := {{ref "encoding/json.Unmarshal"}}(b, &tn)
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if err != nil {
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return err
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}
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switch tn.TypeName {
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{{range .Implementations -}}
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case "{{.GraphQLName}}":
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*v = new({{.GoName}})
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return {{ref "encoding/json.Unmarshal"}}(b, *v)
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{{end -}}
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case "":
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{{/* Likely if we're making a request to a mock server and the author
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of the mock didn't know to add __typename, so give a special
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error. */ -}}
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return {{ref "fmt.Errorf"}}(
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"Response was missing {{.GraphQLName}}.__typename")
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default:
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return {{ref "fmt.Errorf"}}(
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`Unexpected concrete type for {{.GoName}}: "%v"`, tn.TypeName)
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}
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}
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