Move test-runner.mjs to exercise root and add commentary (#1525)

* Move test-runner.mjs to exercise root and add commentary

* Fix for impersonate

* Make executable

common/package.json

@@ -31,7 +31,7 @@
     "typescript-eslint": "^7.18.0"
   },
   "scripts": {
-    "test": "corepack yarn node .meta/test-runner.mjs",
+    "test": "corepack yarn node test-runner.mjs",
     "test:types": "corepack yarn tstyche",
     "test:implementation": "corepack yarn jest --no-cache --passWithNoTests",
     "lint": "corepack yarn lint:types && corepack yarn lint:ci",

common/test-runner.mjs

@@ -0,0 +1,111 @@
+#!/usr/bin/env node
+
+/**
+ * 👋🏽 Hello there reader,
+ *
+ * It looks like you are working on this solution using the Exercism CLI and
+ * not the online editor. That's great! The file you are looking at executes
+ * the various steps the online test-runner also takes.
+ *
+ * @see https://github.com/exercism/typescript-test-runner
+ *
+ * TypeScript track exercises generally consist of at least two out of three
+ * types of tests to run.
+ *
+ * 1. tsc, the TypeScript compiler. This tests if the TypeScript code is valid
+ * 2. tstyche, static analysis tests to see if the types used are expected
+ * 3. jest, runtime implementation tests to see if the solution is correct
+ *
+ * If one of these three fails, this script terminates with -1, -2, or -3
+ * respectively. If it succeeds, it terminates with exit code 0.
+ *
+ * @note you need corepack (bundled with node LTS) enabled in order for this
+ *    test runner to work as expected. Follow the installation and test
+ *    instructions if you see errors about corepack or pnp.
+ */
+
+import { execSync } from 'node:child_process'
+import { readFileSync, existsSync } from 'node:fs'
+import { exit } from 'node:process'
+import { URL } from 'node:url'
+
+/**
+ * Before executing any tests, the test runner attempts to find the
+ * exercise config.json file which has metadata about which types of tests
+ * to run for this solution.
+ */
+const metaDirectory = new URL('./.meta/', import.meta.url)
+const exercismDirectory = new URL('./.exercism/', import.meta.url)
+const configDirectory = existsSync(metaDirectory)
+  ? metaDirectory
+  : execSync(exercismDirectory)
+    ? exercismDirectory
+    : null
+
+if (configDirectory === null) {
+  throw new Error(
+    'Expected .meta or .exercism directory to exist, but I cannot find it.'
+  )
+}
+
+const configFile = new URL('./config.json', configDirectory)
+if (!existsSync(configFile)) {
+  throw new Error('Expected config.json to exist at ' + configFile.toString())
+}
+
+// Experimental: import config from './config.json' with { type: 'json' }
+/** @type {import('./config.json') } */
+const config = JSON.parse(readFileSync(configFile))
+
+const jest = !config.custom || config.custom['flag.tests.jest']
+const tstyche = config.custom?.['flag.tests.tstyche']
+console.log(
+  `[tests] tsc: ✅, tstyche: ${tstyche ? '✅' : '❌'}, jest: ${jest ? '✅' : '❌'}, `
+)
+
+/**
+ * 1. tsc: the typescript compiler
+ */
+try {
+  console.log('[tests] tsc (compile)')
+  execSync('corepack yarn lint:types', {
+    stdio: 'inherit',
+    cwd: process.cwd(),
+  })
+} catch {
+  exit(-1)
+}
+
+/**
+ * 2. tstyche: type tests
+ */
+if (tstyche) {
+  try {
+    console.log('[tests] tstyche (type tests)')
+    execSync('corepack yarn test:types', {
+      stdio: 'inherit',
+      cwd: process.cwd(),
+    })
+  } catch {
+    exit(-2)
+  }
+}
+
+/**
+ * 3. jest: implementation tests
+ */
+if (jest) {
+  try {
+    console.log('[tests] tstyche (implementation tests)')
+    execSync('corepack yarn test:implementation', {
+      stdio: 'inherit',
+      cwd: process.cwd(),
+    })
+  } catch {
+    exit(-3)
+  }
+}
+
+/**
+ * Done! 🥳
+ */

exercises/concept/lasagna/package.json

@@ -28,7 +28,7 @@
     "typescript-eslint": "^7.18.0"
   },
   "scripts": {
-    "test": "corepack yarn node .meta/test-runner.mjs",
+    "test": "corepack yarn node test-runner.mjs",
     "test:types": "corepack yarn tstyche",
     "test:implementation": "corepack yarn jest --no-cache --passWithNoTests",
     "lint": "corepack yarn lint:types && corepack yarn lint:ci",

exercises/concept/lasagna/test-runner.mjs

@@ -0,0 +1,111 @@
+#!/usr/bin/env node
+
+/**
+ * 👋🏽 Hello there reader,
+ *
+ * It looks like you are working on this solution using the Exercism CLI and
+ * not the online editor. That's great! The file you are looking at executes
+ * the various steps the online test-runner also takes.
+ *
+ * @see https://github.com/exercism/typescript-test-runner
+ *
+ * TypeScript track exercises generally consist of at least two out of three
+ * types of tests to run.
+ *
+ * 1. tsc, the TypeScript compiler. This tests if the TypeScript code is valid
+ * 2. tstyche, static analysis tests to see if the types used are expected
+ * 3. jest, runtime implementation tests to see if the solution is correct
+ *
+ * If one of these three fails, this script terminates with -1, -2, or -3
+ * respectively. If it succeeds, it terminates with exit code 0.
+ *
+ * @note you need corepack (bundled with node LTS) enabled in order for this
+ *    test runner to work as expected. Follow the installation and test
+ *    instructions if you see errors about corepack or pnp.
+ */
+
+import { execSync } from 'node:child_process'
+import { readFileSync, existsSync } from 'node:fs'
+import { exit } from 'node:process'
+import { URL } from 'node:url'
+
+/**
+ * Before executing any tests, the test runner attempts to find the
+ * exercise config.json file which has metadata about which types of tests
+ * to run for this solution.
+ */
+const metaDirectory = new URL('./.meta/', import.meta.url)
+const exercismDirectory = new URL('./.exercism/', import.meta.url)
+const configDirectory = existsSync(metaDirectory)
+  ? metaDirectory
+  : execSync(exercismDirectory)
+    ? exercismDirectory
+    : null
+
+if (configDirectory === null) {
+  throw new Error(
+    'Expected .meta or .exercism directory to exist, but I cannot find it.'
+  )
+}
+
+const configFile = new URL('./config.json', configDirectory)
+if (!existsSync(configFile)) {
+  throw new Error('Expected config.json to exist at ' + configFile.toString())
+}
+
+// Experimental: import config from './config.json' with { type: 'json' }
+/** @type {import('./config.json') } */
+const config = JSON.parse(readFileSync(configFile))
+
+const jest = !config.custom || config.custom['flag.tests.jest']
+const tstyche = config.custom?.['flag.tests.tstyche']
+console.log(
+  `[tests] tsc: ✅, tstyche: ${tstyche ? '✅' : '❌'}, jest: ${jest ? '✅' : '❌'}, `
+)
+
+/**
+ * 1. tsc: the typescript compiler
+ */
+try {
+  console.log('[tests] tsc (compile)')
+  execSync('corepack yarn lint:types', {
+    stdio: 'inherit',
+    cwd: process.cwd(),
+  })
+} catch {
+  exit(-1)
+}
+
+/**
+ * 2. tstyche: type tests
+ */
+if (tstyche) {
+  try {
+    console.log('[tests] tstyche (type tests)')
+    execSync('corepack yarn test:types', {
+      stdio: 'inherit',
+      cwd: process.cwd(),
+    })
+  } catch {
+    exit(-2)
+  }
+}
+
+/**
+ * 3. jest: implementation tests
+ */
+if (jest) {
+  try {
+    console.log('[tests] tstyche (implementation tests)')
+    execSync('corepack yarn test:implementation', {
+      stdio: 'inherit',
+      cwd: process.cwd(),
+    })
+  } catch {
+    exit(-3)
+  }
+}
+
+/**
+ * Done! 🥳
+ */