Lay out foundation for this project

.eslintrc.js

@@ -6,7 +6,20 @@ module.exports = {
   overrides: [
     {
       files: ['*.ts'],
-      extends: ['@metamask/eslint-config-typescript'],
+      extends: [
+        '@metamask/eslint-config-typescript',
+        '@metamask/eslint-config-nodejs',
+      ],
+    },
+
+    {
+      files: ['src/cli.ts'],
+      parserOptions: {
+        sourceType: 'script',
+      },
+      rules: {
+        'n/shebang': 'off',
+      },
     },
 
     {
@@ -32,5 +45,6 @@ module.exports = {
     'dist/',
     'docs/',
     '.yarn/',
+    'tmp/',
   ],
 };

.gitignore

@@ -76,3 +76,6 @@ node_modules/
 !.yarn/releases
 !.yarn/sdks
 !.yarn/versions
+
+# This project
+tmp

README.md

@@ -29,6 +29,14 @@ npx @metamask/module-lint
 - Install [Yarn v3](https://yarnpkg.com/getting-started/install)
 - Run `yarn install` to install dependencies and run any required post-install scripts
 
+### Running Locally
+
+To run the tool locally, say:
+
+```
+yarn run-tool [OPTIONS] [ARGUMENTS...]
+```
+
 ### Testing and Linting
 
 Run `yarn test` to run the tests once. To run tests on file changes, run `yarn test:watch`.

jest.config.js

@@ -22,15 +22,17 @@ 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',
+    '!./src/logging-utils.ts',
+  ],
 
   // The directory where Jest should output its coverage files
   coverageDirectory: 'coverage',
 
   // An array of regexp pattern strings used to skip coverage collection
-  // coveragePathIgnorePatterns: [
-  //   "/node_modules/"
-  // ],
+  coveragePathIgnorePatterns: ['/node_modules/', '/tmp'],
 
   // Indicates which provider should be used to instrument code for coverage
   coverageProvider: 'babel',
@@ -159,9 +161,7 @@ module.exports = {
   // ],
 
   // An array of regexp pattern strings that are matched against all test paths, matched tests are skipped
-  // testPathIgnorePatterns: [
-  //   "/node_modules/"
-  // ],
+  testPathIgnorePatterns: ['/node_modules/', '/tmp'],
 
   // The regexp pattern or array of patterns that Jest uses to detect test files
   // testRegex: [],

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/**",
@@ -44,9 +45,21 @@
     "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"
   },
+  "resolutions": {
+    "@jridgewell/gen-mapping": "0.3.3"
+  },
+  "dependencies": {
+    "@metamask/utils": "^8.2.0",
+    "axios": "^1.5.1",
+    "chalk": "^4.1.2",
+    "dependency-graph": "^0.11.0",
+    "execa": "^5.1.1",
+    "yargs": "^17.7.2"
+  },
   "devDependencies": {
     "@lavamoat/allow-scripts": "^2.3.1",
     "@lavamoat/preinstall-always-fail": "^1.0.0",
@@ -58,6 +71,7 @@
     "@swc/cli": "^0.1.62",
     "@swc/core": "^1.3.66",
     "@types/jest": "^28.1.6",
+    "@types/jest-when": "^3.5.3",
     "@types/node": "^16",
     "@typescript-eslint/eslint-plugin": "^5.43.0",
     "@typescript-eslint/parser": "^5.43.0",
@@ -72,9 +86,13 @@
     "eslint-plugin-promise": "^6.1.1",
     "jest": "^28.1.3",
     "jest-it-up": "^2.0.2",
+    "jest-mock-extended": "^3.0.5",
+    "nock": "^13.3.4",
     "prettier": "^2.7.1",
     "prettier-plugin-packagejson": "^2.3.0",
-    "rimraf": "^3.0.2",
+    "rimraf": "^5.0.5",
+    "stdio-mock": "^1.2.0",
+    "strip-ansi": "^6.0.0",
     "ts-jest": "^28.0.7",
     "ts-node": "^10.7.0",
     "typedoc": "^0.23.15",

src/build-rule-tree.test.ts

@@ -0,0 +1,136 @@
+import * as dependencyGraphModule from 'dependency-graph';
+
+import { buildRuleTree } from './build-rule-tree';
+import type { Rule } from './execute-rules';
+
+jest.mock('dependency-graph', () => {
+  return {
+    // eslint-disable-next-line @typescript-eslint/naming-convention
+    __esModule: true,
+    ...jest.requireActual('dependency-graph'),
+  };
+});
+
+describe('buildRuleTree', () => {
+  it('builds a nested data structure that starts with the rules that have no dependencies and navigates through their dependents recursively', () => {
+    const rule1: Rule = {
+      name: 'rule-1',
+      description: 'Description for rule 1',
+      dependencies: ['rule-2'],
+      execute: async () => {
+        return {
+          passed: true,
+        };
+      },
+    };
+    const rule2: Rule = {
+      name: 'rule-2',
+      description: 'Description for rule 2',
+      dependencies: ['rule-3'],
+      execute: async () => {
+        return {
+          passed: true,
+        };
+      },
+    };
+    const rule3: Rule = {
+      name: 'rule-3',
+      description: 'Description for rule 3',
+      dependencies: [],
+      execute: async () => {
+        return {
+          passed: true,
+        };
+      },
+    };
+    const rules = [rule1, rule2, rule3];
+
+    const ruleTree = buildRuleTree(rules);
+
+    expect(ruleTree).toStrictEqual({
+      children: [
+        {
+          rule: rule3,
+          children: [
+            {
+              rule: rule2,
+              children: [
+                {
+                  rule: rule1,
+                  children: [],
+                },
+              ],
+            },
+          ],
+        },
+      ],
+    });
+  });
+
+  it('reinterprets a dependency cycle error from dep-graph if given a set of rules where a dependency cycle is present', () => {
+    const rule1: Rule = {
+      name: 'rule-1',
+      description: 'Description for rule 1',
+      dependencies: ['rule-2'],
+      execute: async () => {
+        return {
+          passed: false,
+          failures: [{ message: 'Oops' }],
+        };
+      },
+    };
+    const rule2: Rule = {
+      name: 'rule-2',
+      description: 'Description for rule 2',
+      dependencies: ['rule-3'],
+      execute: async () => {
+        return {
+          passed: true,
+        };
+      },
+    };
+    const rule3: Rule = {
+      name: 'rule-3',
+      description: 'Description for rule 3',
+      dependencies: ['rule-1'],
+      execute: async () => {
+        return {
+          passed: true,
+        };
+      },
+    };
+    const rules = [rule1, rule2, rule3];
+
+    expect(() => buildRuleTree(rules)).toThrow(
+      new Error(
+        `
+Could not build rule tree as some rules depend on each other circularly:
+
+- Rule "rule-1" depends on...
+  - Rule "rule-2", which depends on...
+    - Rule "rule-3", which depends on...
+      - Rule "rule-1" again (creating the cycle)
+`.trim(),
+      ),
+    );
+  });
+
+  it('re-throws any unknown if given a set of rules where a dependency cycle is present', () => {
+    const error = new Error('oops');
+    const depGraph = new dependencyGraphModule.DepGraph();
+    jest.spyOn(depGraph, 'overallOrder').mockImplementation(() => {
+      throw error;
+    });
+    jest.spyOn(dependencyGraphModule, 'DepGraph').mockReturnValue(depGraph);
+
+    expect(() => buildRuleTree([])).toThrow(error);
+  });
+
+  it('returns an empty root node if given no rules', () => {
+    const ruleTree = buildRuleTree([]);
+
+    expect(ruleTree).toStrictEqual({
+      children: [],
+    });
+  });
+});