feat: integrate AI tooling into ng-dev

Integrates the AI tooling prototype into `ng-dev`.

Author: crisbeto

ng-dev/BUILD.bazel

@@ -22,6 +22,7 @@ ts_library(
         "//ng-dev:__subpackages__",
     ],
     deps = [
+        "//ng-dev/ai",
         "//ng-dev/auth",
         "//ng-dev/caretaker",
         "//ng-dev/commit-message",

ng-dev/ai/BUILD.bazel

@@ -0,0 +1,19 @@
+load("//tools:defaults.bzl", "ts_library")
+
+ts_library(
+    name = "ai",
+    srcs = glob([
+        "**/*.ts",
+    ]),
+    visibility = ["//ng-dev:__subpackages__"],
+    deps = [
+        "//ng-dev/utils",
+        "@npm//@google/genai",
+        "@npm//@types/cli-progress",
+        "@npm//@types/node",
+        "@npm//@types/yargs",
+        "@npm//cli-progress",
+        "@npm//fast-glob",
+        "@npm//yargs",
+    ],
+)

ng-dev/ai/cli.ts

@@ -0,0 +1,15 @@
+/**
+ * @license
+ * Copyright Google LLC
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+import {Argv} from 'yargs';
+import {MigrateModule} from './migrate.js';
+import {FixModule} from './fix.js';
+
+/** Build the parser for the AI commands. */
+export function buildAiParser(localYargs: Argv) {
+  return localYargs.command(MigrateModule).command(FixModule);
+}

ng-dev/ai/consts.ts

@@ -0,0 +1,30 @@
+/**
+ * @license
+ * Copyright Google LLC
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+/** Default model to use for AI-based scripts. */
+export const DEFAULT_MODEL = 'gemini-2.5-flash';
+
+/** Default temperature for AI-based scripts. */
+export const DEFAULT_TEMPERATURE = 0.1;
+
+/** Gets the API key and asserts that it is defined. */
+export function getApiKey(): string {
+  const key = process.env.GEMINI_API_KEY;
+
+  if (!key) {
+    console.error(
+      [
+        'No API key configured. A Gemini API key must be set as the `GEMINI_API_KEY` environment variable.',
+        'For internal users, see go/aistudio-apikey',
+      ].join('\n'),
+    );
+    process.exit(1);
+  }
+
+  return key;
+}

ng-dev/ai/fix.ts

@@ -0,0 +1,267 @@
+/**
+ * @license
+ * Copyright Google LLC
+ *
+ * Use of this source code is governed by an MIT-style license that can be
+ * found in the LICENSE file at https://angular.io/license
+ */
+
+import {createPartFromUri, FileState, GoogleGenAI, Part} from '@google/genai';
+import {setTimeout} from 'node:timers/promises';
+import {readFile, writeFile} from 'node:fs/promises';
+import {basename} from 'node:path';
+import glob from 'fast-glob';
+import assert from 'node:assert';
+import {Bar} from 'cli-progress';
+import {Argv, Arguments, CommandModule} from 'yargs';
+import {randomUUID} from 'node:crypto';
+import {DEFAULT_MODEL, DEFAULT_TEMPERATURE, getApiKey} from './consts.js';
+import {Spinner} from '../utils/spinner.js';
+
+/** Command line options. */
+export interface Options {
+  /** Files that the fix should apply to. */
+  files: string[];
+
+  /** Error message(s) to be resolved. */
+  error: string;
+
+  /** Model that should be used to apply the prompt. */
+  model: string;
+
+  /** Temperature for the model. */
+  temperature: number;
+}
+
+interface FixedFileContent {
+  filePath: string;
+  content: string;
+}
+
+/** Yargs command builder for the command. */
+function builder(argv: Argv): Argv<Options> {
+  return argv
+    .positional('files', {
+      description: `One or more glob patterns to find target files (e.g., 'src/**/*.ts' 'test/**/*.ts').`,
+      type: 'string',
+      array: true,
+      demandOption: true,
+    })
+    .option('error', {
+      alias: 'e',
+      description: 'Full error description from the build process',
+      type: 'string',
+      demandOption: true,
+    })
+    .option('model', {
+      type: 'string',
+      alias: 'm',
+      description: 'Model to use for the migration',
+      default: DEFAULT_MODEL,
+    })
+    .option('temperature', {
+      type: 'number',
+      alias: 't',
+      default: DEFAULT_TEMPERATURE,
+      description: 'Temperature for the model. Lower temperature reduces randomness/creativity',
+    });
+}
+
+/** Yargs command handler for the command. */
+async function handler(options: Arguments<Options>) {
+  const fixedContents = await fixFilesWithAI(
+    options.files,
+    options.error,
+    options.model,
+    options.temperature,
+  );
+  console.log('\n--- AI Suggested Fixes Summary ---');
+  if (fixedContents.length === 0) {
+    console.log(
+      'No files were fixed or found matching the pattern. Check your glob pattern and check whether the files exist.',
+    );
+
+    return;
+  }
+
+  console.log('Updated files:');
+  const writeTasks = fixedContents.map(({filePath, content}) =>
+    writeFile(filePath, content).then(() => console.log(` - ${filePath}`)),
+  );
+  await Promise.all(writeTasks);
+}
+
+async function fixFilesWithAI(
+  globPatterns: string[],
+  errorDescription: string,
+  model: string,
+  temperature: number,
+): Promise<FixedFileContent[]> {
+  const filePaths = await glob(globPatterns, {
+    onlyFiles: true,
+    absolute: false,
+  });
+
+  if (filePaths.length === 0) {
+    console.error(`No files found matching the patterns: ${JSON.stringify(globPatterns)}.`);
+    return [];
+  }
+
+  const ai = new GoogleGenAI({vertexai: false, apiKey: getApiKey()});
+  let uploadedFileNames: string[] = [];
+
+  const progressBar = new Bar({
+    format: `{step} [{bar}] ETA: {eta}s | {value}/{total} files`,
+    clearOnComplete: true,
+  });
+
+  try {
+    const {
+      fileNameMap,
+      partsForGeneration,
+      uploadedFileNames: uploadedFiles,
+    } = await uploadFiles(ai, filePaths, progressBar);
+
+    uploadedFileNames = uploadedFiles;
+
+    const spinner = new Spinner('AI is analyzing the files and generating potential fixes...');
+    const response = await ai.models.generateContent({
+      model,
+      contents: [{text: generatePrompt(errorDescription, fileNameMap)}, ...partsForGeneration],
+      config: {
+        responseMimeType: 'application/json',
+        candidateCount: 1,
+        maxOutputTokens: Infinity,
+        temperature,
+      },
+    });
+
+    const responseText = response.text;
+    if (!responseText) {
+      spinner.failure(`AI returned an empty response.`);
+      return [];
+    }
+
+    const fixes = JSON.parse(responseText) as FixedFileContent[];
+
+    if (!Array.isArray(fixes)) {
+      throw new Error('AI response is not a JSON array.');
+    }
+
+    spinner.complete();
+    return fixes;
+  } finally {
+    if (uploadedFileNames.length) {
+      progressBar.start(uploadedFileNames.length, 0, {
+        step: 'Deleting temporary uploaded files',
+      });
+      const deleteTasks = uploadedFileNames.map((name) => {
+        return ai.files
+          .delete({name})
+          .catch((error) =>
+            console.warn(`WARNING: Failed to delete temporary file ${name}:`, error),
+          )
+          .finally(() => progressBar.increment());
+      });
+
+      await Promise.allSettled(deleteTasks).finally(() => progressBar.stop());
+    }
+  }
+}
+
+async function uploadFiles(
+  ai: GoogleGenAI,
+  filePaths: string[],
+  progressBar: Bar,
+): Promise<{
+  uploadedFileNames: string[];
+  partsForGeneration: Part[];
+  fileNameMap: Map<string, string>;
+}> {
+  const uploadedFileNames: string[] = [];
+  const partsForGeneration: Part[] = [];
+  const fileNameMap = new Map<string, string>();
+
+  progressBar.start(filePaths.length, 0, {step: 'Uploading files'});
+
+  const uploadPromises = filePaths.map(async (filePath) => {
+    try {
+      const uploadedFile = await ai.files.upload({
+        file: new Blob([await readFile(filePath, {encoding: 'utf8'})], {
+          type: 'text/plain',
+        }),
+        config: {
+          displayName: `fix_request_${basename(filePath)}_${randomUUID()}`,
+        },
+      });
+
+      assert(uploadedFile.name, 'File name cannot be undefined after upload.');
+
+      let getFile = await ai.files.get({name: uploadedFile.name});
+      while (getFile.state === FileState.PROCESSING) {
+        await setTimeout(500); // Wait for 500ms before re-checking
+        getFile = await ai.files.get({name: uploadedFile.name});
+      }
+
+      if (getFile.state === FileState.FAILED) {
+        throw new Error(`File processing failed on API for ${filePath}. Skipping this file.`);
+      }
+
+      if (getFile.uri && getFile.mimeType) {
+        const filePart = createPartFromUri(getFile.uri, getFile.mimeType);
+        partsForGeneration.push(filePart);
+        fileNameMap.set(filePath, uploadedFile.name);
+        progressBar.increment();
+        return uploadedFile.name; // Return the name on success
+      } else {
+        throw new Error(
+          `Uploaded file for ${filePath} is missing URI or MIME type after processing. Skipping.`,
+        );
+      }
+    } catch (error: any) {
+      console.error(`Error uploading or processing file ${filePath}: ${error.message}`);
+      return null; // Indicate failure for this specific file
+    }
+  });
+
+  const results = await Promise.allSettled(uploadPromises).finally(() => progressBar.stop());
+
+  for (const result of results) {
+    if (result.status === 'fulfilled' && result.value !== null) {
+      uploadedFileNames.push(result.value);
+    }
+  }
+
+  return {uploadedFileNames, fileNameMap, partsForGeneration};
+}
+
+function generatePrompt(errorDescription: string, fileNameMap: Map<string, string>): string {
+  return `
+    You are a highly skilled software engineer, specializing in Bazel, Starlark, Python, Angular, JavaScript,
+    TypeScript, and everything related.
+    The following files are part of a build process that failed with the error:
+    \`\`\`
+    ${errorDescription}
+    \`\`\`
+    Please analyze the content of EACH provided file and suggest modifications to resolve the issue.
+
+    Your response MUST be a JSON array of objects. Each object in the array MUST have two properties:
+    'filePath' (the full path from the mappings provided.) and 'content' (the complete corrected content of that file).
+    DO NOT include any additional text, non modified files, commentary, or markdown outside the JSON array.
+    For example:
+    [
+      {"filePath": "/full-path-from-mappings/file1.txt", "content": "Corrected content for file1."},
+      {"filePath": "/full-path-from-mappings/file2.js", "content": "console.log('Fixed JS');"}
+    ]
+
+    IMPORTANT: The input files are mapped as follows: ${Array.from(fileNameMap.entries())}
+`;
+}
+
+/** CLI command module. */
+export const FixModule: CommandModule<{}, Options> = {
+  builder,
+  handler,
+  command: 'fix <files..>',
+  describe: 'Fixes errors from the specified error output',
+};