Add remaining code to complete MVP

All of the commits up to now have been adding code to support an MVP
version of this tool. This commit ties up the MVP by adding a first
rule, which merely verifies that a project has a `src/` directory, the
entrypoint function to the tool, and the executable which kicks off the
whole thing. This commit also adds a package script, `run-tool`, which
can be used in development to quickly smoke test new changes.

.eslintrc.js

@@ -27,6 +27,18 @@ module.exports = {
         '@metamask/eslint-config-nodejs',
       ],
     },
+
+    {
+      files: ['src/cli.ts'],
+      parserOptions: {
+        sourceType: 'script',
+      },
+      rules: {
+        // It's okay if this file has a shebang; it's meant to be executed
+        // directly.
+        'n/shebang': 'off',
+      },
+    },
   ],
 
   ignorePatterns: [

.gitignore

@@ -76,3 +76,6 @@ node_modules/
 !.yarn/releases
 !.yarn/sdks
 !.yarn/versions
+
+# Repositories that this tool clones, and other temporary data
+tmp

jest.config.js

@@ -22,7 +22,7 @@ module.exports = {
   collectCoverage: true,
 
   // An array of glob patterns indicating a set of files for which coverage information should be collected
-  collectCoverageFrom: ['./src/**/*.ts'],
+  collectCoverageFrom: ['./src/**/*.ts', '!./src/cli.ts'],
 
   // The directory where Jest should output its coverage files
   coverageDirectory: 'coverage',

package.json

@@ -22,6 +22,7 @@
   "main": "./dist/cjs/index.js",
   "module": "./dist/esm/index.js",
   "types": "./dist/types/index.d.ts",
+  "bin": "./dist/cli.js",
   "files": [
     "dist/cjs/**",
     "dist/esm/**",
@@ -44,14 +45,16 @@
     "lint:fix": "yarn lint:eslint --fix && yarn lint:constraints --fix && yarn lint:misc --write && yarn lint:dependencies && yarn lint:changelog",
     "lint:misc": "prettier '**/*.json' '**/*.md' '!CHANGELOG.md' '**/*.yml' '!.yarnrc.yml' --ignore-path .gitignore --no-error-on-unmatched-pattern",
     "prepack": "./scripts/prepack.sh",
+    "run-tool": "ts-node --swc src/cli.ts",
     "test": "jest && jest-it-up",
     "test:watch": "jest --watch"
   },
   "dependencies": {
     "@metamask/utils": "^8.2.0",
     "chalk": "^4.1.2",
     "dependency-graph": "^0.11.0",
-    "execa": "^5.1.1"
+    "execa": "^5.1.1",
+    "yargs": "^17.7.2"
   },
   "devDependencies": {
     "@lavamoat/allow-scripts": "^2.3.1",

src/cli.ts

@@ -0,0 +1,22 @@
+#!/usr/bin/env node
+
+import {
+  DEFAULT_PROJECT_NAMES,
+  DEFAULT_CACHED_REPOSITORIES_DIRECTORY_PATH,
+} from './constants';
+import { main } from './main';
+
+main({
+  argv: process.argv,
+  stdout: process.stdout,
+  stderr: process.stderr,
+  config: {
+    cachedRepositoriesDirectoryPath: DEFAULT_CACHED_REPOSITORIES_DIRECTORY_PATH,
+    defaultProjectNames: DEFAULT_PROJECT_NAMES,
+  },
+}).catch((error) => {
+  console.error(error);
+  process.exitCode = 1;
+});
+
+// vi: ft=typescript

src/constants.ts

@@ -1,5 +1,129 @@
+import path from 'path';
+
 /**
  * The number of milliseconds in an hour, used to determine when to pull the
  * latest changes for previously cached repositories.
  */
 export const ONE_HOUR = 60 * 60 * 1000;
+
+/**
+ * The name of this project. Used to exclude this repo as a lintable project.
+ */
+export const THIS_PROJECT_NAME = 'module-lint';
+
+/**
+ * The root directory of this project.
+ */
+export const THIS_PROJECT_DIRECTORY_PATH = path.resolve(__dirname, '..');
+
+/**
+ * Wherever the tool was run.
+ */
+export const WORKING_DIRECTORY_PATH = process.cwd();
+
+/**
+ * The usage text printed when the user requests help or provides invalid input.
+ */
+export const USAGE_TEXT = `
+Analyzes one or more repos for divergence from a template repo.
+
+${THIS_PROJECT_NAME} OPTIONS [ARGUMENTS...]
+
+Pass the names of one or more MetaMask repositories to lint them, or pass
+nothing to lint all MetaMask repositories.
+`.trim();
+
+/**
+ * In order to lint a remote repository, that repository must be cloned first.
+ * This is the temporary directory where the clone lives.
+ */
+export const DEFAULT_CACHED_REPOSITORIES_DIRECTORY_PATH = path.join(
+  THIS_PROJECT_DIRECTORY_PATH,
+  'tmp/repositories',
+);
+
+/**
+ * The name of the template repository that project repositories will be
+ * compared to. The only such repository we have is the module template.
+ */
+export const DEFAULT_TEMPLATE_REPOSITORY_NAME = 'metamask-module-template';
+
+/**
+ * All of the remote MetaMask repositories that will be linted if a list is not
+ * explicitly provided.
+ *
+ * Derived from: <https://github.com/MetaMask/core/issues/1079>
+ */
+export const DEFAULT_PROJECT_NAMES = [
+  'KeyringController',
+  'abi-utils',
+  'action-create-release-pr',
+  'action-is-release',
+  'action-npm-publish',
+  'action-publish-gh-pages',
+  'action-publish-release',
+  'action-tech-challenge-setup',
+  'action-utils',
+  'actions-test-repo',
+  'api-playground',
+  'api-specs',
+  'auto-changelog',
+  'bify-module-groups',
+  'browser-passworder',
+  'contract-metadata',
+  'create-release-branch',
+  'design-tokens',
+  'detect-provider',
+  'docusaurus-openrpc',
+  'eth-block-tracker',
+  'eth-hd-keyring',
+  'eth-json-rpc-filters',
+  'eth-json-rpc-infura',
+  'eth-json-rpc-middleware',
+  'eth-json-rpc-provider',
+  'eth-ledger-bridge-keyring',
+  'eth-method-registry',
+  'eth-phishing-detect',
+  'eth-sig-util',
+  'eth-simple-keyring',
+  'eth-snap-keyring',
+  'eth-token-tracker',
+  'eth-trezor-keyring',
+  'ethereum-provider-openrpc-generator',
+  'etherscan-link',
+  'extension-port-stream',
+  'extension-provider',
+  'iframe-ee-openrpc-inspector-transport',
+  'json-rpc-engine',
+  'json-rpc-middleware-stream',
+  'key-tree',
+  'keyring-api',
+  'keyring-snaps-registry',
+  'logo',
+  'metamask-eth-abis',
+  'metamask-onboarding',
+  'mobile-provider',
+  'noble-secp256k1-compat-wrapper',
+  'nonce-tracker',
+  'object-multiplex',
+  'obs-store',
+  'open-rpc-docs-react',
+  'openrpc-inspector-transport',
+  'phishing-warning',
+  'post-message-stream',
+  'ppom-validator',
+  'providers',
+  'rpc-errors',
+  'safe-event-emitter',
+  'smart-transactions-controller',
+  'snap-simple-keyring',
+  'snaps-registry',
+  'state-log-explorer',
+  'swappable-obj-proxy',
+  'template-sync',
+  'test-dapp',
+  'types',
+  'utils',
+  'vault-decryptor',
+  'web3-stream-provider',
+];

src/establish-metamask-repository.ts

@@ -84,6 +84,9 @@ export async function establishMetaMaskRepository({
   if (existingRepository.isKnownMetaMaskRepository) {
     await requireDefaultBranchSelected(existingRepository);
 
+    log(
+      `(${existingRepository.shortname}) Ensuring default branch is up to date...`,
+    );
     const updatedLastFetchedDate = await ensureDefaultBranchIsUpToDate(
       existingRepository.directoryPath,
       existingRepository.lastFetchedDate,