feat: Add backend-function runtime behavior to get the data config

.changeset/brave-cheetahs-repeat.md

@@ -0,0 +1,6 @@
+---
+'@aws-amplify/backend': patch
+'@aws-amplify/backend-function': patch
+---
+
+feat: Add backend-function runtime behavior to get the data config

packages/backend-function/package.json

@@ -10,6 +10,11 @@
       "types": "./lib/index.d.ts",
       "import": "./lib/index.js",
       "require": "./lib/index.js"
+    },
+    "./runtime": {
+      "types": "./lib/runtime/index.d.ts",
+      "import": "./lib/runtime/index.js",
+      "require": "./lib/runtime/index.js"
     }
   },
   "main": "lib/index.js",
@@ -22,11 +27,13 @@
     "@aws-amplify/backend-output-schemas": "^1.4.0",
     "@aws-amplify/backend-output-storage": "^1.1.3",
     "@aws-amplify/plugin-types": "^1.4.0",
+    "@aws-sdk/client-s3": "^3.624.0",
     "execa": "^8.0.1"
   },
   "devDependencies": {
     "@aws-amplify/backend-platform-test-stubs": "^0.3.6",
     "@aws-amplify/platform-core": "^1.1.0",
+    "@aws-sdk/client-s3": "^3.624.0",
     "@aws-sdk/client-ssm": "^3.624.0",
     "aws-sdk": "^2.1550.0",
     "uuid": "^9.0.1"

packages/backend-function/src/factory.ts

@@ -44,6 +44,7 @@ import { FunctionEnvironmentTranslator } from './function_env_translator.js';
 import { FunctionEnvironmentTypeGenerator } from './function_env_type_generator.js';
 import { FunctionLayerArnParser } from './layer_parser.js';
 import { convertFunctionSchedulesToRuleSchedules } from './schedule_parser.js';
+import { FunctionDataConfigGenerator } from './function_data_config_generator.js';
 
 const functionStackType = 'function-Lambda';
 
@@ -425,6 +426,10 @@ class AmplifyFunction
     // This will be overwritten with the typed file at the end of synthesis
     functionEnvironmentTypeGenerator.generateProcessEnvShim();
 
+    const functionClientConfigGenerator = new FunctionDataConfigGenerator(id);
+
+    functionClientConfigGenerator.generateDataConfigShim();
+
     let functionLambda: NodejsFunction;
     try {
       functionLambda = new NodejsFunction(scope, `${id}-lambda`, {

packages/backend-function/src/function_data_config_generator.test.ts

@@ -0,0 +1,53 @@
+import { describe, it, mock } from 'node:test';
+import fs from 'fs';
+import { FunctionDataConfigGenerator } from './function_data_config_generator.js';
+import assert from 'assert';
+import { pathToFileURL } from 'url';
+import { FunctionEnvironmentTypeGenerator } from './function_env_type_generator.js';
+
+void describe('FunctionDataConfigGenerator', () => {
+  void it('generates a type definition file', () => {
+    const fsOpenSyncMock = mock.method(fs, 'openSync');
+    const fsWriteFileSyncMock = mock.method(fs, 'writeFileSync', () => null);
+    fsOpenSyncMock.mock.mockImplementation(() => 0);
+    const functionDataConfigGenerator = new FunctionDataConfigGenerator(
+      'testFunction'
+    );
+    const configExport =
+      'export const { libraryOptions, resourceConfig } = await internalGetAmplifyClientConfiguration(env);';
+
+    functionDataConfigGenerator.generateDataConfigShim();
+
+    // assert type definition file path
+    assert.equal(
+      fsWriteFileSyncMock.mock.calls[0].arguments[0],
+      `${process.cwd()}/.amplify/generated/data-config/testFunction.ts`
+    );
+
+    // assert content
+    assert.ok(
+      fsWriteFileSyncMock.mock.calls[0].arguments[1]
+        ?.toString()
+        .includes(configExport)
+    );
+
+    mock.restoreAll();
+  });
+
+  void it('generated data configuration file has valid syntax', async () => {
+    const functionDataConfigGenerator = new FunctionDataConfigGenerator(
+      'testFunction'
+    );
+    const filePath = `${process.cwd()}/.amplify/generated/data-config/testFunction.ts`;
+
+    functionDataConfigGenerator.generateDataConfigShim();
+
+    // The data config shim depends upon the env shim, so we need to build it for the config to be importable
+    const functionEnvironmentTypeGenerator =
+      new FunctionEnvironmentTypeGenerator('testFunction');
+    functionEnvironmentTypeGenerator.generateTypedProcessEnvShim(['TEST_ENV']);
+
+    // import to validate syntax of data config file
+    await import(pathToFileURL(filePath).toString());
+  });
+});

packages/backend-function/src/function_data_config_generator.ts

@@ -0,0 +1,45 @@
+import fs from 'fs';
+import path from 'path';
+
+const lambdaDataConfigTemplate = (
+  functionName: string
+) => `// This file is auto-generated by Amplify. Edits will be overwritten.
+import { internalGetAmplifyClientConfiguration } from "@aws-amplify/backend-function/runtime";
+import { env } from "../env/${functionName}";
+export const { libraryOptions, resourceConfig } = await internalGetAmplifyClientConfiguration(env);
+`;
+
+/**
+ * Generates the data configuration imports
+ */
+export class FunctionDataConfigGenerator {
+  private typeDefFilePath: string;
+
+  private indentation: string = '  ';
+
+  /**
+   * Initialize data configuration file name and location
+   */
+  constructor(private readonly functionName: string) {
+    this.typeDefFilePath = `${process.cwd()}/.amplify/generated/data-config/${
+      this.functionName
+    }.ts`;
+  }
+
+  /**
+   * Generate data-config shim
+   */
+  generateDataConfigShim = () => {
+    this.writeShimFile(lambdaDataConfigTemplate(this.functionName));
+  };
+
+  private writeShimFile = (content: string) => {
+    const typeDefFileDirname = path.dirname(this.typeDefFilePath);
+
+    if (!fs.existsSync(typeDefFileDirname)) {
+      fs.mkdirSync(typeDefFileDirname, { recursive: true });
+    }
+
+    fs.writeFileSync(this.typeDefFilePath, content);
+  };
+}

packages/backend-function/src/function_env_type_generator.test.ts

@@ -1,6 +1,5 @@
 import { describe, it, mock } from 'node:test';
 import fs from 'fs';
-import fsp from 'fs/promises';
 import { FunctionEnvironmentTypeGenerator } from './function_env_type_generator.js';
 import assert from 'assert';
 import { pathToFileURL } from 'url';
@@ -57,7 +56,6 @@ void describe('FunctionEnvironmentTypeGenerator', () => {
   });
 
   void it('generated type definition file has valid syntax', async () => {
-    const targetDirectory = await fsp.mkdtemp('func_env_type_gen_test');
     const functionEnvironmentTypeGenerator =
       new FunctionEnvironmentTypeGenerator('testFunction');
     const filePath = `${process.cwd()}/.amplify/generated/env/testFunction.ts`;
@@ -66,8 +64,6 @@ void describe('FunctionEnvironmentTypeGenerator', () => {
 
     // import to validate syntax of type definition file
     await import(pathToFileURL(filePath).toString());
-
-    await fsp.rm(targetDirectory, { recursive: true, force: true });
   });
 
   void it('does not generate duplicate environment variables', () => {