Partially defined enumValue support (#10419)

* Add failing test for #10418

* Fix enum resolver for partially mapped enumValues

* Add changeset

* Missing queries in test

* Prefer valueName over name node

---------

Co-authored-by: Eddy Nguyen <[email protected]>

Author: chdanielmueller

.changeset/mighty-hornets-laugh.md

@@ -0,0 +1,5 @@
+---
+'@graphql-codegen/typescript-resolvers': patch
+---
+
+Fix enum resolver for partially mapped enumValues

packages/plugins/typescript/resolvers/src/visitor.ts

@@ -134,9 +134,12 @@ export class TypeScriptResolversVisitor extends BaseResolversVisitor<
     return `{ ${(node.values || [])
       .map(v => {
         const valueName = v.name as any as string;
-        const mappedValue = valuesMapping[valueName];
+        const mappedValue = valuesMapping[valueName] ?? valueName;
+        const hasMapping = !!valuesMapping[valueName];
 
-        return `${valueName}: ${typeof mappedValue === 'number' ? mappedValue : `'${mappedValue}'`}`;
+        return `${valueName}${hasMapping || this.config.avoidOptionals.resolvers ? '' : '?'}: ${
+          typeof mappedValue === 'number' ? mappedValue : `'${mappedValue}'`
+        }`;
       })
       .join(', ')} }`;
   }

packages/plugins/typescript/resolvers/tests/ts-resolvers.spec.ts

@@ -336,6 +336,54 @@ __isTypeOf?: IsTypeOfResolverFn<ParentType, ContextType>;
       expect(mergedOutput).toContain(`export type MyEnumResolvers = { A: 'val_1', B: 'val_2', C: 'val_3' };`);
     });
 
+    it('#10418 - Should generate enum internal values resolvers when enum has enumValues set as object with partially explicit values', async () => {
+      const testSchema = buildSchema(/* GraphQL */ `
+        type Query {
+          v: MyEnum
+          w: MyEnum
+          x: MyEnum
+        }
+
+        enum MyEnum {
+          A
+          B
+          C
+        }
+      `);
+      const config = {
+        noSchemaStitching: true,
+        enumValues: {
+          MyEnum: {
+            A: 'val_1',
+          },
+        },
+      };
+      const result = await plugin(testSchema, [], config, { outputFile: '' });
+
+      const mergedOutput = await resolversTestingValidate(
+        result,
+        config,
+        testSchema,
+        `
+        export const resolvers: Resolvers = {
+          MyEnum: {
+            A: 'val_1',
+            B: 'B'
+          },
+          Query: {
+            v: () => 'val_1',
+            w: () => 'B',
+            z: () => 'C',
+          }
+        };
+      `
+      );
+
+      expect(mergedOutput).not.toContain(ENUM_RESOLVERS_SIGNATURE);
+      expect(mergedOutput).not.toContain('EnumResolverSignature');
+      expect(mergedOutput).toContain(`export type MyEnumResolvers = { A: 'val_1', B?: 'B', C?: 'C' };`);
+    });
+
     it('Should generate enum internal values resolvers when enum has enumValues set as external enum', async () => {
       const testSchema = buildSchema(/* GraphQL */ `
         type Query {