Added harness mode for Next.js.

genkit-tools/common/package.json

@@ -19,10 +19,12 @@
     "configstore": "^5.0.1",
     "express": "^4.18.2",
     "get-port": "5.1.1",
+    "glob": "^10.3.12",
     "inquirer": "^8.2.0",
     "js-yaml": "^4.1.0",
     "json-2-csv": "^5.5.1",
     "open": "^6.3.0",
+    "tsx": "^4.9.3",
     "uuid": "^9.0.1",
     "winston": "^3.11.0",
     "yaml": "^2.4.1",

genkit-tools/common/src/plugin/config.ts

@@ -71,6 +71,12 @@ const ToolsConfigSchema = z
       })
       .optional(),
     evaluators: z.array(EvaluatorConfig).optional(),
+    runner: z
+      .object({
+        mode: z.enum(['default', 'harness']).default('default'),
+        files: z.array(z.string()).optional(),
+      })
+      .optional(),
   })
   .strict();
 

genkit-tools/common/src/runner/harness.ts

@@ -0,0 +1,30 @@
+/**
+ * Copyright 2024 Google LLC
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+import { glob } from 'glob';
+import * as path from 'path';
+import { logger } from '../utils';
+
+async function main() {
+  logger.info(`Loading file paths: ${process.argv[2]}`);
+  const files = await glob(process.argv[2].split(','));
+  for (const file of files) {
+    logger.info(`Loading \`${file}\`...`);
+    await import(path.join(process.cwd(), file));
+  }
+}
+
+main();

genkit-tools/common/src/runner/runner.ts

@@ -157,12 +157,16 @@ export class Runner {
    * Starts the app code in a subprocess.
    */
   private async startApp(): Promise<boolean> {
+    const config = await findToolsConfig();
     const runtime = detectRuntime(process.cwd());
     let command = '';
     let args: string[] = [];
     switch (runtime) {
       case 'node':
-        command = 'node';
+        command =
+          config?.runner?.mode === 'harness'
+            ? path.join(__dirname, '../../../node_modules/.bin/tsx')
+            : 'node';
         break;
       case 'go':
         command = 'go';
@@ -172,7 +176,11 @@ export class Runner {
         throw Error(`Unexpected runtime while starting app code: ${runtime}`);
     }
 
-    const entryPoint = getEntryPoint(process.cwd());
+    const harnessEntryPoint = path.join(__dirname, '../runner/harness.js');
+    const entryPoint =
+      config?.runner?.mode === 'default'
+        ? getEntryPoint(process.cwd())
+        : harnessEntryPoint;
     if (!entryPoint) {
       logger.error(
         'Could not detect entry point for app. Make sure you are at the root of your project directory.'
@@ -184,7 +192,14 @@ export class Runner {
       return false;
     }
 
-    logger.info(`Starting app at \`${entryPoint}\`...`);
+    const files = config?.runner?.files;
+    if (config?.runner?.mode === 'harness') {
+      logger.info(
+        `Running harness with file paths:\n - ${files?.join('\n - ') || ' - None'}`
+      );
+    } else {
+      logger.info(`Starting app at \`${entryPoint}\`...`);
+    }
 
     // Try the desired port first then fall back to default range.
     let port = await getPort({ port: this.reflectionApiPort });
@@ -199,6 +214,9 @@ export class Runner {
     this.reflectionApiPort = port;
 
     args.push(entryPoint);
+    if (config?.runner?.mode === 'harness' && files) {
+      args.push(files.join(','));
+    }
     this.appProcess = spawn(command, args, {
       stdio: 'inherit',
       env: {