Add some more tests for config validation, and fix some gaps (#274)

I set these tests up in #270, but I realized there's a lot more we could
test unrelated to that PR. In this commit I add some more tests. They're
not really exhaustive yet, but they did catch a few bugs, which I fixed:
- we weren't validating the package-name if you do set it (only if we
guess it)
- If you omitted `generated`, you would try to write generated code to
the directory containing `genqlient.yaml`, which makes no sense; now we
default to `generated.go`. In the real world it's probably good to set
explicitly, but it's actually very convenient in tests that we don't
have to, and maybe in small projects too.

generate/testdata/invalid-config/InvalidCasing.yaml

@@ -1,3 +1,4 @@
+package: invalidConfig
 casing:
   enums:
     MyType: bogus

generate/testdata/invalid-config/InvalidOptional.yaml

@@ -0,0 +1,2 @@
+package: invalidConfig
+optional: bogus

generate/testdata/invalid-config/InvalidPackage.yaml

@@ -0,0 +1 @@
+package: bogus-package-name

generate/testdata/snapshots/TestGenerateWithConfig-PackageBindings-testdata-queries-generated.go

@@ -1,6 +1,6 @@
 // Code generated by github.com/Khan/genqlient, DO NOT EDIT.
 
-package testdata
+package queries
 
 import (
 	"context"

generate/testdata/snapshots/TestInvalidConfigs-CantGuessPackage.yaml

@@ -0,0 +1,3 @@
+invalid config file testdata/invalid-config/CantGuessPackage.yaml: unable to guess package-name: 'invalid-config' is not a valid identifier
+Set package name in genqlient.yaml
+Example: https://github.com/Khan/genqlient/blob/main/example/genqlient.yaml#L6

generate/testdata/snapshots/TestInvalidConfigs-InvalidOptional.yaml

@@ -0,0 +1 @@
+invalid config file testdata/invalid-config/InvalidOptional.yaml: optional must be one of: 'value' (default), 'pointer', or 'generic'

generate/testdata/snapshots/TestInvalidConfigs-InvalidPackage.yaml

@@ -0,0 +1 @@
+invalid config file testdata/invalid-config/InvalidPackage.yaml: invalid package in genqlient.yaml: 'bogus-package-name' is not a valid identifier

generate/testdata/snapshots/TestValidConfigs-Lists.yaml

@@ -0,0 +1,27 @@
+(*generate.Config)({
+  Schema: (generate.StringList) (len=2) {
+    (string) (len=42) "testdata/valid-config/first_schema.graphql",
+    (string) (len=43) "testdata/valid-config/second_schema.graphql"
+  },
+  Operations: (generate.StringList) (len=2) {
+    (string) (len=46) "testdata/valid-config/first_operations.graphql",
+    (string) (len=47) "testdata/valid-config/second_operations.graphql"
+  },
+  Generated: (string) (len=34) "testdata/valid-config/generated.go",
+  Package: (string) (len=11) "validConfig",
+  ExportOperations: (string) "",
+  ContextType: (string) (len=15) "context.Context",
+  ClientGetter: (string) "",
+  Bindings: (map[string]*generate.TypeBinding) <nil>,
+  PackageBindings: ([]*generate.PackageBinding) <nil>,
+  Casing: (generate.Casing) {
+    AllEnums: (generate.CasingAlgorithm) "",
+    Enums: (map[string]generate.CasingAlgorithm) <nil>
+  },
+  Optional: (string) "",
+  OptionalGenericType: (string) "",
+  StructReferences: (bool) false,
+  Extensions: (bool) false,
+  AllowBrokenFeatures: (bool) false,
+  baseDir: (string) (len=21) "testdata/valid-config"
+})

generate/testdata/snapshots/TestValidConfigs-Simple.yaml

@@ -0,0 +1,21 @@
+(*generate.Config)({
+  Schema: (generate.StringList) <nil>,
+  Operations: (generate.StringList) <nil>,
+  Generated: (string) (len=34) "testdata/valid-config/generated.go",
+  Package: (string) (len=11) "validConfig",
+  ExportOperations: (string) "",
+  ContextType: (string) (len=15) "context.Context",
+  ClientGetter: (string) "",
+  Bindings: (map[string]*generate.TypeBinding) <nil>,
+  PackageBindings: ([]*generate.PackageBinding) <nil>,
+  Casing: (generate.Casing) {
+    AllEnums: (generate.CasingAlgorithm) "",
+    Enums: (map[string]generate.CasingAlgorithm) <nil>
+  },
+  Optional: (string) "",
+  OptionalGenericType: (string) "",
+  StructReferences: (bool) false,
+  Extensions: (bool) false,
+  AllowBrokenFeatures: (bool) false,
+  baseDir: (string) (len=21) "testdata/valid-config"
+})

generate/testdata/snapshots/TestValidConfigs-Strings.yaml

@@ -0,0 +1,25 @@
+(*generate.Config)({
+  Schema: (generate.StringList) (len=1) {
+    (string) (len=36) "testdata/valid-config/schema.graphql"
+  },
+  Operations: (generate.StringList) (len=1) {
+    (string) (len=40) "testdata/valid-config/operations.graphql"
+  },
+  Generated: (string) (len=34) "testdata/valid-config/generated.go",
+  Package: (string) (len=11) "validConfig",
+  ExportOperations: (string) "",
+  ContextType: (string) (len=15) "context.Context",
+  ClientGetter: (string) "",
+  Bindings: (map[string]*generate.TypeBinding) <nil>,
+  PackageBindings: ([]*generate.PackageBinding) <nil>,
+  Casing: (generate.Casing) {
+    AllEnums: (generate.CasingAlgorithm) "",
+    Enums: (map[string]generate.CasingAlgorithm) <nil>
+  },
+  Optional: (string) "",
+  OptionalGenericType: (string) "",
+  StructReferences: (bool) false,
+  Extensions: (bool) false,
+  AllowBrokenFeatures: (bool) false,
+  baseDir: (string) (len=21) "testdata/valid-config"
+})

generate/testdata/valid-config/Lists.yaml

@@ -0,0 +1,9 @@
+schema:
+- first_schema.graphql
+- second_schema.graphql
+
+operations:
+- first_operations.graphql
+- second_operations.graphql
+
+package: validConfig

generate/testdata/valid-config/Simple.yaml

@@ -0,0 +1 @@
+package: validConfig

generate/testdata/valid-config/Strings.yaml

@@ -0,0 +1,3 @@
+schema: schema.graphql
+operations: operations.graphql
+package: validConfig