Schema Coordinates for Metafields, extracted from graphql#3044

The original schema coordinates PR on v17 (graphql#3044), since backported to 16.x.x, had non-specified support for schema coordinates for metafields.

Co-authored-by: Benjie Gillam <benjie@jemjie.com>
Co-authored-by: Mark Larah <mark@larah.me>
Co-authored-by: Yaacov Rydzinski <yaacovCR@gmail.com>

Author: 4 people

cspell.yml

@@ -40,6 +40,7 @@ words:
   - Coodinate
   - metafield
   - graphiql
+  - metafield
   - uncoerce
   - uncoerced
 

src/utilities/__tests__/resolveSchemaCoordinate-test.ts

@@ -1,8 +1,9 @@
-import { expect } from 'chai';
+import { assert, expect } from 'chai';
 import { describe, it } from 'mocha';
 
 import type {
   GraphQLEnumType,
+  GraphQLField,
   GraphQLInputObjectType,
   GraphQLObjectType,
 } from '../../type/definition.js';
@@ -181,3 +182,68 @@ describe('resolveSchemaCoordinate', () => {
     );
   });
 });
+
+/*
+ * NOTE: the following are not required for spec compliance; resolution
+ * of meta-fields is implementation-defined.
+ *
+ * These tests are here to ensure a change of behavior will only be made
+ * in a semver-major release of GraphQL.js.
+ */
+describe('resolveSchemaCoordinate (meta-fields and introspection types)', () => {
+  it('resolves a meta-field', () => {
+    const type = schema.getType('Business') as GraphQLObjectType;
+    const field = schema.getField(type, '__typename');
+    assert.ok(field);
+    expect(
+      resolveSchemaCoordinate(schema, 'Business.__typename'),
+    ).to.deep.equal({
+      kind: 'Field',
+      type,
+      field,
+    });
+  });
+
+  it('resolves a meta-field argument', () => {
+    const type = schema.getType('Query') as GraphQLObjectType;
+    const field = schema.getField(type, '__type') as GraphQLField;
+    const fieldArgument = field.args.find((arg) => arg.name === 'name');
+    expect(
+      resolveSchemaCoordinate(schema, 'Query.__type(name:)'),
+    ).to.deep.equal({
+      kind: 'FieldArgument',
+      type,
+      field,
+      fieldArgument,
+    });
+  });
+
+  it('resolves an Introspection Type', () => {
+    expect(resolveSchemaCoordinate(schema, '__Type')).to.deep.equal({
+      kind: 'NamedType',
+      type: schema.getType('__Type'),
+    });
+  });
+
+  it('resolves an Introspection Type Field', () => {
+    const type = schema.getType('__Directive') as GraphQLObjectType;
+    const field = type.getFields().name;
+    expect(resolveSchemaCoordinate(schema, '__Directive.name')).to.deep.equal({
+      kind: 'Field',
+      type,
+      field,
+    });
+  });
+
+  it('resolves an Introspection Type Enum Value', () => {
+    const type = schema.getType('__DirectiveLocation') as GraphQLEnumType;
+    const enumValue = type.getValue('INLINE_FRAGMENT');
+    expect(
+      resolveSchemaCoordinate(schema, '__DirectiveLocation.INLINE_FRAGMENT'),
+    ).to.deep.equal({
+      kind: 'EnumValue',
+      type,
+      enumValue,
+    });
+  });
+});

src/utilities/resolveSchemaCoordinate.ts

@@ -185,7 +185,7 @@ function resolveMemberCoordinate(
   // 6. Otherwise:
   // 1. Let {fieldName} be the value of the second {Name}.
   const fieldName = schemaCoordinate.memberName.value;
-  const field = type.getFields()[fieldName];
+  const field = schema.getField(type, fieldName);
 
   // 2. Return the field of {type} named {fieldName} if it exists.
   if (field == null) {
@@ -222,7 +222,7 @@ function resolveArgumentCoordinate(
   // 4. Let {fieldName} be the value of the second {Name}.
   // 5. Let {field} be the field of {type} named {fieldName}.
   const fieldName = schemaCoordinate.fieldName.value;
-  const field = type.getFields()[fieldName];
+  const field = schema.getField(type, fieldName);
 
   // 7. Assert: {field} must exist.
   if (field == null) {