Allow to have declarationKind of type: class, interface: interface

dotansimha · Mar 7, 2021 · e947f8e · e947f8e
1 parent 3cba883
commit e947f8e
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Showing 3 changed files with 41 additions and 2 deletions.
diff --git a/.changeset/gentle-hairs-trade.md b/.changeset/gentle-hairs-trade.md
@@ -0,0 +1,6 @@
+---
+'@graphql-codegen/visitor-plugin-common': patch
+'@graphql-codegen/typescript': patch
+---
+
+Allow to have declarationKind of type: class, interface: interface
diff --git a/packages/plugins/other/visitor-plugin-common/src/base-types-visitor.ts b/packages/plugins/other/visitor-plugin-common/src/base-types-visitor.ts
@@ -345,7 +345,7 @@ export class BaseTypesVisitor<
     originalNode: ObjectTypeDefinitionNode
   ): DeclarationBlock {
     const optionalTypename = this.config.nonOptionalTypename ? '__typename' : '__typename?';
-    const { type } = this._parsedConfig.declarationKind;
+    const { type, interface: interfacesType } = this._parsedConfig.declarationKind;
     const allFields = [
       ...(this.config.addTypename
         ? [
@@ -368,7 +368,9 @@ export class BaseTypesVisitor<
 
     if (type === 'interface' || type === 'class') {
       if (interfacesNames.length > 0) {
-        declarationBlock.withContent('extends ' + interfacesNames.join(', ') + (allFields.length > 0 ? ' ' : ' {}'));
+        const keyword = interfacesType === 'interface' && type === 'class' ? 'implements' : 'extends';
+
+        declarationBlock.withContent(`${keyword} ` + interfacesNames.join(', ') + (allFields.length > 0 ? ' ' : ' {}'));
       }
 
       declarationBlock.withBlock(this.mergeAllFields(allFields, false));

diff --git a/packages/plugins/typescript/typescript/tests/typescript.spec.ts b/packages/plugins/typescript/typescript/tests/typescript.spec.ts
@@ -495,6 +495,37 @@ describe('TypeScript', () => {
   });
 
   describe('Issues', () => {
+    it('#5643 - Incorrect combinations of declartionKinds leads to syntax error', async () => {
+      const testSchema = buildSchema(/* GraphQL */ `
+        interface Base {
+          id: ID!
+        }
+
+        type MyType implements Base {
+          id: ID!
+        }
+
+        type Query {
+          t: MyType!
+        }
+      `);
+
+      const result = (await plugin(
+        testSchema,
+        [],
+        {
+          declarationKind: {
+            type: 'class',
+            interface: 'interface',
+          },
+        },
+        { outputFile: '' }
+      )) as Types.ComplexPluginOutput;
+      const output = mergeOutputs([result]);
+      expect(output).not.toContain(`export class MyType extends Base {`);
+      expect(output).toContain(`export class MyType implements Base {`);
+    });
+
     it('#4564 - numeric enum values set on schema level', async () => {
       const testSchema = new GraphQLSchema({
         types: [