#1380 Include __typename in fragments and metadata fields

dotansimha · Mar 6, 2019 · 1cbb746 · 1cbb746
1 parent e884404
commit 1cbb746
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Showing 3 changed files with 178 additions and 4 deletions.
diff --git a/packages/plugins/typescript-documents/tests/ts-documents.spec.ts b/packages/plugins/typescript-documents/tests/ts-documents.spec.ts
@@ -711,5 +711,139 @@ describe('TypeScript Documents Plugin', async () => {
       `)
       );
     });
+
+    it('should use __typename in fragments when requested', async () => {
+      const testSchema = makeExecutableSchema({
+        typeDefs: parse(/* GraphQL */ `
+          type Post {
+            title: String
+          }
+          type Query {
+            post: Post!
+          }
+        `)
+      });
+      const query = parse(/* GraphQL */ `
+        query Post {
+          post {
+            ... on Post {
+              __typename
+            }
+          }
+        }
+      `);
+
+      const content = await plugin(
+        testSchema,
+        [{ filePath: '', content: query }],
+        {},
+        {
+          outputFile: 'graphql.ts'
+        }
+      );
+
+      expect(format(content)).toBeSimilarStringTo(
+        format(`
+          export type PostQuery = { __typename?: 'Query' } & { post: { __typename?: 'Post' } & ({ __typename: 'Post' }) };
+        `)
+      );
+    });
+
+    it('should handle introspection types (__schema)', async () => {
+      const testSchema = makeExecutableSchema({
+        typeDefs: parse(/* GraphQL */ `
+          type Post {
+            title: String
+          }
+          type Query {
+            post: Post!
+          }
+        `)
+      });
+      const query = parse(/* GraphQL */ `
+        query Info {
+          __schema {
+            queryType {
+              fields {
+                name
+              }
+            }
+          }
+        }
+      `);
+
+      const content = await plugin(
+        testSchema,
+        [{ filePath: '', content: query }],
+        {},
+        {
+          outputFile: 'graphql.ts'
+        }
+      );
+
+      expect(format(content)).toBeSimilarStringTo(
+        format(`
+          export type InfoQuery = { __typename?: 'Query' } & {
+            __schema: { __typename?: '__Schema' } & {
+              queryType: { __typename?: '__Type' } & { fields: Maybe<Array<{ __typename?: '__Field' } & Pick<__Field, 'name'>>> };
+            };
+          };
+        `)
+      );
+    });
+
+    it('should handle introspection types (__type)', async () => {
+      const testSchema = makeExecutableSchema({
+        typeDefs: parse(/* GraphQL */ `
+          type Post {
+            title: String
+          }
+          type Query {
+            post: Post!
+          }
+        `)
+      });
+      const query = parse(/* GraphQL */ `
+        query Info {
+          __type(name: "Post") {
+            name
+            fields {
+              name
+              type {
+                name
+                kind
+              }
+            }
+          }
+        }
+      `);
+
+      const content = await plugin(
+        testSchema,
+        [{ filePath: '', content: query }],
+        {},
+        {
+          outputFile: 'graphql.ts'
+        }
+      );
+
+      expect(format(content)).toBeSimilarStringTo(
+        format(`
+        export type InfoQuery = { __typename?: 'Query' } & {
+          __type: Maybe<
+            { __typename?: '__Type' } & Pick<__Type, 'name'> & {
+                fields: Maybe<
+                  Array<
+                    { __typename?: '__Field' } & Pick<__Field, 'name'> & {
+                        type: { __typename?: '__Type' } & Pick<__Type, 'name' | 'kind'>;
+                      }
+                  >
+                >;
+              }
+          >;
+        };
+      `)
+      );
+    });
   });
 });
diff --git a/packages/plugins/visitor-plugin-common/src/base-documents-visitor.ts b/packages/plugins/visitor-plugin-common/src/base-documents-visitor.ts
@@ -8,11 +8,23 @@ import {
   FragmentDefinitionNode,
   GraphQLObjectType,
   OperationDefinitionNode,
-  VariableDefinitionNode
+  VariableDefinitionNode,
+  OperationTypeNode
 } from 'graphql';
 import { SelectionSetToObject } from './selection-set-to-object';
 import { OperationVariablesToObject } from './variables-to-object';
 
+function getRootType(operation: OperationTypeNode, schema: GraphQLSchema) {
+  switch (operation) {
+    case 'query':
+      return schema.getQueryType();
+    case 'mutation':
+      return schema.getMutationType();
+    case 'subscription':
+      return schema.getSubscriptionType();
+  }
+}
+
 export interface ParsedDocumentsConfig {
   scalars: ScalarsMap;
   convert: (str: string) => string;
@@ -108,7 +120,7 @@ export class BaseDocumentsVisitor<
 
   OperationDefinition = (node: OperationDefinitionNode): string => {
     const name = this.handleAnonymouseOperation(node.name && node.name.value ? node.name.value : null);
-    const operationRootType = this._schema.getType(toPascalCase(node.operation)) as GraphQLObjectType;
+    const operationRootType = getRootType(node.operation, this._schema);
     const selectionSet = this._selectionSetToObject.createNext(operationRootType, node.selectionSet);
     const visitedOperationVariables = this._variablesTransfomer.transform<VariableDefinitionNode>(
       node.variableDefinitions

diff --git a/packages/plugins/visitor-plugin-common/src/selection-set-to-object.ts b/packages/plugins/visitor-plugin-common/src/selection-set-to-object.ts
@@ -9,7 +9,11 @@ import {
   isUnionType,
   isInterfaceType,
   isEnumType,
-  GraphQLSchema
+  GraphQLSchema,
+  isEqualType,
+  GraphQLField,
+  SchemaMetaFieldDef,
+  TypeMetaFieldDef
 } from 'graphql';
 import { getBaseType, quoteIfNeeded } from './utils';
 import { ScalarsMap, ConvertNameFn } from './types';
@@ -21,6 +25,23 @@ export type LinkField = { alias: string; name: string; type: string; selectionSe
 export type FragmentSpreadField = string;
 export type InlineFragmentField = { [onType: string]: string[] };
 
+function isMetadataFieldName(name: string) {
+  return ['__schema', '__type'].includes(name);
+}
+
+function isRootType(type: GraphQLNamedType, schema: GraphQLSchema): type is GraphQLObjectType {
+  return (
+    isEqualType(type, schema.getQueryType()) ||
+    isEqualType(type, schema.getMutationType()) ||
+    isEqualType(type, schema.getSubscriptionType())
+  );
+}
+
+const metadataFieldMap: Record<string, GraphQLField<any, any>> = {
+  __schema: SchemaMetaFieldDef,
+  __type: TypeMetaFieldDef
+};
+
 export class SelectionSetToObject {
   protected _primitiveFields: PrimitiveField[] = [];
   protected _primitiveAliasedFields: PrimitiveAliasedFields[] = [];
@@ -57,7 +78,14 @@ export class SelectionSetToObject {
     }
 
     if (isObjectType(this._parentSchemaType) || isInterfaceType(this._parentSchemaType)) {
-      const schemaField = this._parentSchemaType.getFields()[field.name.value];
+      let schemaField: GraphQLField<any, any>;
+
+      if (isRootType(this._parentSchemaType, this._schema) && isMetadataFieldName(field.name.value)) {
+        schemaField = metadataFieldMap[field.name.value];
+      } else {
+        schemaField = this._parentSchemaType.getFields()[field.name.value];
+      }
+
       const rawType = schemaField.type as any;
       const baseType = getBaseType(rawType);
       const typeName = baseType.name;