allow users to overwrite resolvers and pipeline functions

packages/amplify-e2e-core/src/utils/api.ts

@@ -11,3 +11,8 @@ export function updateConfig(projectDir: string, projectName: string, config: an
   const configPath = path.join(projectDir, 'amplify', 'backend', 'api', projectName, TRANSFORM_CONFIG_FILE_NAME);
   fs.writeFileSync(configPath, JSON.stringify(config, null, 4));
 }
+
+export function addCustomResolver(projectDir: string, projectName: string, resolverName: string, resolver: string) {
+  const resolverPath = path.join(projectDir, 'amplify', 'backend', 'api', projectName, 'resolvers', resolverName);
+  fs.writeFileSync(resolverPath, resolver);
+}

packages/amplify-e2e-tests/src/__tests__/resolvers.test.ts

@@ -0,0 +1,43 @@
+import {
+  initJSProjectWithProfile,
+  deleteProject,
+  createNewProjectDir,
+  deleteProjectDir,
+  addFeatureFlag,
+  addApiWithSchema,
+  addCustomResolver,
+  apiGqlCompile,
+} from 'amplify-e2e-core';
+import { join } from 'path';
+import * as fs from 'fs-extra';
+
+describe('overriding generated resolvers', () => {
+  let projectDir: string;
+  let apiName = 'simpleapi';
+
+  beforeAll(async () => {
+    projectDir = await createNewProjectDir('overrideresolvers');
+    await initJSProjectWithProfile(projectDir, {});
+
+    addFeatureFlag(projectDir, 'graphqltransformer', 'useexperimentalpipelinedtransformer', true);
+  });
+
+  afterAll(async () => {
+    await deleteProject(projectDir);
+    deleteProjectDir(projectDir);
+  });
+
+  it('adds the overwritten resolver to the build', async () => {
+    const resolverName = 'Query.listTodos.req.vtl';
+    const resolver = '$util.unauthorized()';
+    const generatedResolverPath = join(projectDir, 'amplify', 'backend', 'api', apiName, 'build', 'pipelineFunctions', resolverName);
+
+    await addApiWithSchema(projectDir, 'simple_model.graphql');
+    await apiGqlCompile(projectDir, true);
+
+    addCustomResolver(projectDir, apiName, resolverName, resolver);
+    await apiGqlCompile(projectDir, true);
+
+    expect(fs.readFileSync(generatedResolverPath)).toEqual(resolver);
+  });
+});

packages/amplify-provider-awscloudformation/src/__tests__/graphql-transformer/utils.test.ts

@@ -0,0 +1,63 @@
+import { mergeUserConfigWithTransformOutput } from '../../graphql-transformer/utils';
+import { TransformerProjectConfig, DeploymentResources } from '@aws-amplify/graphql-transformer-core';
+
+describe('mergeUserConfigWithTransformOutput', () => {
+  let userConfig;
+  let transformerOutput;
+
+  beforeAll(() => {
+    transformerOutput = {
+      resolvers: {},
+      pipelineFunctions: {
+        'Query.listTodos.req.vtl': '## [Start] List Request. **\n' + '#set( $limit = $util.defaultIfNull($context.args.limit, 100) )\n',
+      },
+      functions: {},
+      schema: '',
+      stackMapping: {},
+      stacks: {},
+      rootStack: null,
+    } as DeploymentResources;
+  });
+
+  describe('has user-created resolvers', () => {
+    beforeAll(() => {
+      userConfig = {
+        schema: '',
+        functions: {},
+        pipelineFunctions: {},
+        resolvers: {
+          'Query.listTodos.req.vtl': '$util.unauthorized\n',
+        },
+        stacks: {},
+        config: { Version: 5, ElasticsearchWarning: true },
+      } as TransformerProjectConfig;
+    });
+
+    it('merges the custom resolver with transformer output', () => {
+      const output = mergeUserConfigWithTransformOutput(userConfig, transformerOutput);
+
+      expect(output.pipelineFunctions['Query.listTodos.req.vtl']).toEqual('$util.unauthorized\n');
+    });
+  });
+
+  describe('has user created pipeline function', () => {
+    beforeAll(() => {
+      userConfig = {
+        schema: '',
+        functions: {},
+        pipelineFunctions: {
+          'Query.listTodos.req.vtl': '$util.unauthorized\n',
+        },
+        resolvers: {},
+        stacks: {},
+        config: { Version: 5, ElasticsearchWarning: true },
+      } as TransformerProjectConfig;
+    });
+
+    it('merges custom pipeline function with transformer output', () => {
+      const output = mergeUserConfigWithTransformOutput(userConfig, transformerOutput);
+
+      expect(output.pipelineFunctions['Query.listTodos.req.vtl']).toEqual('$util.unauthorized\n');
+    });
+  });
+});

packages/amplify-provider-awscloudformation/src/graphql-transformer/transform-graphql-schema.ts

@@ -24,7 +24,7 @@ import {
 import { SearchableModelTransformer } from '@aws-amplify/graphql-searchable-transformer';
 import { ProviderName as providerName } from '../constants';
 import { hashDirectory } from '../upload-appsync-files';
-import { writeDeploymentToDisk } from './utils';
+import { mergeUserConfigWithTransformOutput, writeDeploymentToDisk } from './utils';
 import { loadProject as readTransformerConfiguration } from './transform-config';
 import { loadProject } from 'graphql-transformer-core';
 import { AppSyncAuthConfiguration } from '@aws-amplify/graphql-transformer-core';
@@ -432,5 +432,8 @@ async function _buildProject(opts: ProjectOptions<TransformerFactoryArgs>) {
     stacks: opts.projectConfig.stacks || {},
     featureFlags: new AmplifyCLIFeatureFlagAdapter(),
   });
-  return transform.transform(userProjectConfig.schema.toString());
+
+  const transformOutput = transform.transform(userProjectConfig.schema.toString());
+
+  return mergeUserConfigWithTransformOutput(userProjectConfig, transformOutput);
 }

packages/amplify-provider-awscloudformation/src/graphql-transformer/utils.ts

@@ -85,6 +85,20 @@ export function readFromPath(directory: string): any {
   return accum;
 }
 
+export function mergeUserConfigWithTransformOutput(userConfig: any, transformOutput: any) {
+  const userResolvers = userConfig.resolvers || {};
+  const userPipelineFunctions = userConfig.pipelineFunctions || {};
+  const pipelineFunctions = transformOutput.pipelineFunctions;
+
+  for (const userResolver of Object.keys(userResolvers)) pipelineFunctions[userResolver] = userResolvers[userResolver];
+  for (const userResolver of Object.keys(userPipelineFunctions)) pipelineFunctions[userResolver] = userPipelineFunctions[userResolver];
+
+  return {
+    ...transformOutput,
+    pipelineFunctions,
+  };
+}
+
 /**
  * Writes a deployment to disk at a path.
  */