Migrate codebase to typescript

Author: lo1tuma

.c8rc.json

@@ -1,15 +1,15 @@
 {
     "all": true,
-    "lines": 100,
-    "statements": 100,
-    "functions": 100,
-    "branches": 100,
+    "lines": 98.4,
+    "statements": 98.4,
+    "functions": 99.6,
+    "branches": 95,
     "check-coverage": true,
     "extension": [".js"],
     "instrument": false,
-    "src": ".",
+    "src": "./target/build",
     "reporter": ["lcov", "text-summary"],
     "reportDir": "./target/coverage",
     "tempDirectory": "./target/c8-temporary-output",
-    "exclude": ["target", "test", "benchmarks/", "eslint.config.js"]
+    "exclude": ["**/*.test.js", "target/build/benchmarks/", "eslint.config.js"]
 }

.github/workflows/ci.yml

@@ -17,6 +17,8 @@ jobs:
                   node-version: ${{ matrix.node }}
             - name: Install dependencies
               run: npm ci
+            - name: Compile
+              run: npm run compile
             - name: Run linters
               run: npm run lint
             - name: Run tests

.mocharc.json

@@ -0,0 +1,14 @@
+{
+    "diff": true,
+    "forbid-pending": true,
+    "extension": ["js"],
+    "spec": [],
+    "exclude": [],
+    "jobs": 1,
+    "parallel": false,
+    "enable-source-maps": true,
+    "reporter": "dot",
+    "slow": 75,
+    "timeout": 2000,
+    "ui": "bdd"
+}

README.md

@@ -17,13 +17,13 @@ npm install --save-dev eslint-plugin-mocha
 
 ### Configuration via `eslint.config.js`
 
-To use this plugin with [the new eslint configuration format (flat config)](https://eslint.org/docs/latest/use/configure/configuration-files-new):
+To use this plugin with [eslint flat configuration format](https://eslint.org/docs/latest/use/configure/configuration-files-new):
 
 ```js
 import mochaPlugin from "eslint-plugin-mocha";
 
 export default [
-    mochaPlugin.configs.flat.recommended, // or `mochaPlugin.configs.flat.all` to enable all
+    mochaPlugin.configs.recommended, // or `mochaPlugin.configs.all` to enable all
     // ... Your configurations here
 ];
 ```
@@ -89,26 +89,6 @@ This plugin supports the following settings, which are used by multiple rules:
 
 - `interface`: This allows to select either `TDD`, `BDD` (default) or `exports`. When using `exports` mocha variables are resolved from named `import` statements instead of global variables.
 
-## Configs
-
-### `recommended`
-
-This plugin exports a recommended config that enforces good practices.
-
-Enable it with the extends option:
-
-```json
-{
-    "extends": ["plugin:mocha/recommended"]
-}
-```
-
-### `all`
-
-There's also a configuration that enables all of our rules.
-
-See [Configuring Eslint](http://eslint.org/docs/user-guide/configuring) on [eslint.org](http://eslint.org) for more info.
-
 ## Rules
 
 <!-- begin auto-generated rules list -->

benchmarks/measure.js

@@ -0,0 +1,103 @@
+import os from 'node:os';
+import { performance as performanceHooks } from 'node:perf_hooks';
+
+const [{ speed: cpuSpeed = 0 } = {}] = os.cpus();
+
+export { cpuSpeed };
+
+export async function importFresh(modulePath: string): Promise<void> {
+    const cacheBuster = `${performanceHooks.now()}_${Math.random()}`;
+    const cacheBustingModulePath = `${modulePath}?buster=${cacheBuster}`;
+
+    await import(cacheBustingModulePath);
+}
+
+function isPositiveNumber(value: number): boolean {
+    return value > 0;
+}
+
+type Result = {
+    readonly duration: number;
+    readonly memory: number;
+};
+
+type MedianResult = {
+    readonly medianDuration: number;
+    readonly medianMemory: number;
+};
+
+function median(list: readonly number[]): number {
+    const listParts = 2;
+    const medianIndex = Math.floor(list.length / listParts);
+    const lowerValue = list[medianIndex - 1] ?? 0;
+    const upperValue = list[medianIndex] ?? 0;
+
+    if (list.length % listParts === 0) {
+        return (lowerValue + upperValue) / listParts;
+    }
+
+    return upperValue;
+}
+
+export function runSyncBenchmark(fn: () => void, count: number): Readonly<MedianResult> {
+    const results: Result[] = [];
+
+    Array.from({ length: count }).forEach(() => {
+        const startTime = performanceHooks.now();
+        const startMemory = process.memoryUsage.rss();
+        fn();
+        const endTime = performanceHooks.now();
+        const endMemory = process.memoryUsage.rss();
+        const duration = endTime - startTime;
+        const memory = endMemory - startMemory;
+
+        results.push({ duration, memory });
+    });
+
+    const medianDuration = median(results.map((result) => {
+        return result.duration;
+    }));
+    const medianMemory = median(
+        results
+            .map((result) => {
+                return result.memory;
+            })
+            .filter(isPositiveNumber)
+    );
+
+    return { medianDuration, medianMemory };
+}
+
+async function measureSingleAsyncTask(fn: () => Promise<void>): Promise<Result> {
+    const startTime = performanceHooks.now();
+    const startMemory = process.memoryUsage().rss;
+    await fn();
+    const endTime = performanceHooks.now();
+    const endMemory = process.memoryUsage().rss;
+    const duration = endTime - startTime;
+    const memory = endMemory - startMemory;
+
+    return { duration, memory };
+}
+
+export async function runAsyncBenchmark(fn: () => Promise<void>, count: number): Promise<MedianResult> {
+    const results = [];
+
+    for (let iteration = 0; iteration < count; iteration += 1) {
+        const result = await measureSingleAsyncTask(fn);
+        results.push(result);
+    }
+
+    const medianDuration = median(results.map((result) => {
+        return result.duration;
+    }));
+    const medianMemory = median(
+        results
+            .map((result) => {
+                return result.memory;
+            })
+            .filter(isPositiveNumber)
+    );
+
+    return { medianDuration, medianMemory };
+}

benchmarks/measure.ts

@@ -1,25 +1,26 @@
 import { Linter } from 'eslint';
 import assert from 'node:assert';
-import { times } from 'rambda';
-import mochaPlugin from '../index.js';
+import mochaPlugin from '../source/plugin.js';
 import { cpuSpeed, runSyncBenchmark } from './measure.js';
 
-const allRules = mochaPlugin.configs.all.rules;
+const { configs: { all } = {} } = mochaPlugin;
 
-function lintManyFilesWithAllRecommendedRules(options) {
+type Options = {
+    readonly numberOfFiles: number;
+};
+
+function lintManyFilesWithAllRecommendedRules(options: Readonly<Options>): void {
     const { numberOfFiles } = options;
     const linter = new Linter();
 
-    const config = {
-        plugins: { mocha: mochaPlugin },
-        rules: allRules,
+    const config: Linter.Config[] = [all as Linter.Config, {
         languageOptions: {
             sourceType: 'script',
             ecmaVersion: 2018
         }
-    };
+    }];
 
-    times((index) => {
+    Array.from({ length: numberOfFiles }).forEach((_value, index) => {
         const codeToLint = `
             'use strict';
             const assert = require('assert');
@@ -73,7 +74,7 @@ function lintManyFilesWithAllRecommendedRules(options) {
         `;
 
         linter.verify(codeToLint, config);
-    }, numberOfFiles);
+    });
 }
 
 const iterations = 50;
@@ -95,7 +96,7 @@ describe('runtime', function () {
     });
 
     it('should not consume more memory as the defined budget to lint many files with the recommended config', function () {
-        const budget = 2_250_000;
+        const budget = 4_500_000;
 
         const { medianMemory } = runSyncBenchmark(() => {
             lintManyFilesWithAllRecommendedRules({ numberOfFiles: 350 });

benchmarks/runtime.bench.js renamed to benchmarks/runtime.bench.ts

@@ -9,7 +9,7 @@ describe('startup / require time', function () {
         const budget = cpuAgnosticBudget / cpuSpeed;
 
         const { medianDuration } = await runAsyncBenchmark(async () => {
-            await importFresh('../index.js');
+            await importFresh('../source/plugin.js');
         }, iterations);
 
         assert.strictEqual(
@@ -20,10 +20,10 @@ describe('startup / require time', function () {
     });
 
     it('should not consume more memory as the defined budget', async function () {
-        const budget = 225_000;
+        const budget = 350_000;
 
         const { medianMemory } = await runAsyncBenchmark(async () => {
-            await importFresh('../index.js');
+            await importFresh('../source/plugin.js');
         }, iterations);
 
         assert.strictEqual(

benchmarks/startup.bench.js renamed to benchmarks/startup.bench.ts

@@ -0,0 +1,10 @@
+{
+    "extends": "../tsconfig.base.json",
+    "compilerOptions": {
+        "tsBuildInfoFile": "../target/buildcache/benchmarks.tsbuildinfo",
+        "rootDir": "..",
+        "types": ["node", "mocha"]
+    },
+    "include": ["./**/*.ts"],
+    "references": [{ "path": "../source/tsconfig.sources.json" }]
+}

benchmarks/tsconfig.json

@@ -7,7 +7,6 @@
         "xcustom",
         "Toru",
         "Nagashima",
-        "rambda",
         "quuux"
     ]
 }