Migrate to Jest 17, ESM, and config packages (#944)

Author: SleeplessByte

.eslintignore

@@ -11,9 +11,3 @@
 # Configuration
 /config
 
-# These have their own config files (not overrides)
-/common/*
-/exercises/*
-
-# typescript-eslint can't lint correctly files in a project without extension
-/scripts/*

.eslintrc

@@ -1,21 +1,12 @@
 {
   "root": true,
-  "parser": "@typescript-eslint/parser",
-  "parserOptions": {
-    "project": "./tsconfig.json",
-    "ecmaFeatures": {
-      "jsx": true
-    },
-    "ecmaVersion": 2020,
-    "sourceType": "module"
-  },
   "extends": "@exercism/eslint-config-typescript",
   "env": {
     "jest": true
   },
   "overrides": [
     {
-      "files": ["**/.meta/proof.ci.ts", "**/.meta/exemplar.ts", "**/*.test.ts"],
+      "files": [".meta/proof.ci.ts", ".meta/exemplar.ts", "*.test.ts"],
       "excludedFiles": ["custom.test.ts"],
       "extends": "@exercism/eslint-config-typescript/maintainers"
     }

.github/workflows/action-format.yml

@@ -62,8 +62,6 @@ jobs:
 
       - name: 'Format code'
         run: ./bin/format.sh
-        env:
-          EXERCISM_PRETTIER_VERSION: '2.3.2'
 
       - name: 'Commit formatted code'
         run: |

.github/workflows/verify-code-formatting.yml

@@ -14,5 +14,3 @@ jobs:
 
       - name: 'Verify formatting of all files'
         run: ./bin/check-formatting.sh
-        env:
-          EXERCISM_PRETTIER_VERSION: '2.3.2'

.prettierignore

@@ -2,3 +2,6 @@
 /.github/workflows/sync-labels.yml
 exercises/**/README.md
 !/README.md
+
+# These are formatted via configlet and will not match prettier
+exercises/**/.meta/config.json

babel.config.cjs

@@ -0,0 +1,4 @@
+module.exports = {
+  presets: ['@exercism/babel-preset-typescript'],
+  plugins: [],
+}

babel.config.js

@@ -1,3 +1,27 @@
 #!/bin/bash
 
+if [ -z "$EXERCISM_PRETTIER_VERSION" ]; then
+  echo "Pulling prettier version from package.json"
+  EXERCISM_PRETTIER_VERSION=$(yarn list --pattern prettier | grep -Po '.*\sprettier@\K.*')
+fi
+
+if [ -z "$EXERCISM_PRETTIER_VERSION" ]; then
+  echo "---------------------------------------------------"
+  echo "This script requires the EXERCISM_PRETTIER_VERSION variable to work."
+  echo "Please see https://exercism.org/docs/building/markdown/style-guide for guidance."
+  echo "---------------------------------------------------"
+  echo "This is what yarn list reports:"
+  echo "$(yarn list --pattern prettier)"
+  echo ""
+  echo "This is the version that can be extracted:"
+  echo "$(yarn list --pattern prettier | grep -Po '.*\sprettier@\K.*')"
+  echo ""
+  echo "These files are found in the repo root:"
+  echo "$(ls -p | grep -v /)"
+  echo "---------------------------------------------------"
+  exit 1
+else
+ echo "Running format with prettier@$EXERCISM_PRETTIER_VERSION"
+fi
+
 npx "prettier@$EXERCISM_PRETTIER_VERSION" --check "**/*.{js,jsx,ts,tsx,css,sass,scss,html,json,md,yml}"

bin/check-formatting.sh

@@ -1,9 +1,27 @@
 #!/usr/bin/env bash
 
 if [ -z "$EXERCISM_PRETTIER_VERSION" ]; then
-	echo "This script requires the EXERCISM_PRETTIER_VERSION variable to work."
-	echo "Please see https://github.com/exercism/v3/blob/master/docs/maintainers/style-guide.md for guidance."
-	exit 1
+  echo "Pulling prettier version from package.json"
+  EXERCISM_PRETTIER_VERSION=$(yarn list --pattern prettier | grep -Po '.*\sprettier@\K.*')
+fi
+
+if [ -z "$EXERCISM_PRETTIER_VERSION" ]; then
+  echo "---------------------------------------------------"
+  echo "This script requires the EXERCISM_PRETTIER_VERSION variable to work."
+  echo "Please see https://exercism.org/docs/building/markdown/style-guide for guidance."
+  echo "---------------------------------------------------"
+  echo "This is what yarn list reports:"
+  echo "$(yarn list --pattern prettier)"
+  echo ""
+  echo "This is the version that can be extracted:"
+  echo "$(yarn list --pattern prettier | grep -Po '.*\sprettier@\K.*')"
+  echo ""
+  echo "These files are found in the repo root:"
+  echo "$(ls -p | grep -v /)"
+  echo "---------------------------------------------------"
+  exit 1
+else
+ echo "Running format with prettier@$EXERCISM_PRETTIER_VERSION"
 fi
 
 npx "prettier@$EXERCISM_PRETTIER_VERSION" --write "**/*.{js,jsx,ts,tsx,css,sass,scss,html,json,md,yml}"

bin/format.sh

@@ -8,5 +8,6 @@
 node_modules/*
 
 # Configuration files
-babel.config.js
-jest.config.js
+.eslintrc.cjs
+babel.config.cjs
+jest.config.cjs

common/.eslintignore

@@ -0,0 +1,38 @@
+module.exports = {
+  root: true,
+  parserOptions: {
+    tsconfigRootDir: __dirname,
+    project: ['./tsconfig.json'],
+  },
+  overrides: [
+    // Student provided files
+    {
+      files: ['*.ts'],
+      excludedFiles: ['.meta/proof.ci.ts', '.meta/exemplar.ts', '*.test.ts'],
+      extends: '@exercism/eslint-config-typescript',
+    },
+    // Exercism given tests
+    {
+      files: ['*.test.ts'],
+      excludedFiles: ['custom.test.ts'],
+      env: {
+        jest: true,
+      },
+      extends: '@exercism/eslint-config-typescript/maintainers',
+    },
+    // Student provided tests
+    {
+      files: ['custom.test.ts'],
+      env: {
+        jest: true,
+      },
+      extends: '@exercism/eslint-config-typescript',
+    },
+    // Exercism provided files
+    {
+      files: ['.meta/proof.ci.ts', '.meta/exemplar.ts', '*.test.ts'],
+      excludedFiles: ['custom.test.ts'],
+      extends: '@exercism/eslint-config-typescript/maintainers',
+    },
+  ],
+}

common/.eslintrc

@@ -0,0 +1,4 @@
+module.exports = {
+  presets: ['@exercism/babel-preset-typescript'],
+  plugins: [],
+}

common/.eslintrc.cjs

@@ -11,21 +11,20 @@
     "type": "git",
     "url": "https://github.com/exercism/typescript"
   },
+  "type": "module",
+  "engines": {
+    "node": "^14.13.1 || >=16.0.0"
+  },
   "devDependencies": {
-    "@babel/core": "^7.16.5",
-    "@babel/plugin-proposal-class-properties": "^7.16.5",
-    "@babel/plugin-proposal-object-rest-spread": "^7.16.5",
-    "@babel/plugin-syntax-bigint": "^7.8.3",
-    "@babel/preset-env": "^7.16.11",
-    "@babel/preset-typescript": "^7.16.5",
-    "@types/jest": "^26.0.24",
-    "@types/node": "^16.11.20",
+    "@exercism/babel-preset-typescript": "^0.1.0",
     "@exercism/eslint-config-typescript": "^0.4.0",
-    "babel-jest": "^26.6.3",
-    "core-js": "^3.19.3",
-    "eslint": "^8.7.0",
-    "eslint-plugin-import": "^2.25.4",
-    "jest": "^26.6.3",
+    "@types/jest": "^27.4.0",
+    "@types/node": "^16.11.24",
+    "babel-jest": "^27.5.1",
+    "core-js": "^3.21.0",
+    "eslint": "^8.9.0",
+    "jest": "^27.5.1",
+    "prettier": "^2.5.1",
     "typescript": "^4.5.4"
   },
   "scripts": {

common/babel.config.cjs

@@ -1,19 +1,28 @@
 {
-  "display": "Configuration for Node LTS",
+  "display": "Configuration for Exercism TypeScript Exercises",
   "compilerOptions": {
-    "lib": ["es2020", "dom"],
-    "module": "commonjs",
-    "target": "es2020",
+    // Allows you to use the newest syntax, and have access to console.log
+    // https://www.typescriptlang.org/tsconfig#lib
+    "lib": ["ESNEXT", "dom"],
+    // Make sure typescript is configured to output ESM
+    // https://gist.github.com/sindresorhus/a39789f98801d908bbc7ff3ecc99d99c#how-can-i-make-my-typescript-project-output-esm
+    "module": "ES2020",
+    // Since this project is using babel, TypeScript may target something very
+    // high, and babel will make sure it runs on your local Node version.
+    // https://babeljs.io/docs/en/
+    "target": "ESNext", // ESLint doesn't support this yet: "es2022",
 
     "strict": true,
     "esModuleInterop": true,
     "skipLibCheck": true,
     "forceConsistentCasingInFileNames": true,
 
-    // Because we'll be using babel
-    // Ensure that Babel can safely transpile files in the TypeScript project
+    // Because we'll be using babel: ensure that Babel can safely transpile
+    // files in the TypeScript project.
+    //
+    // https://babeljs.io/docs/en/babel-plugin-transform-typescript/#caveats
     "isolatedModules": true
   },
-  "include": ["*", ".meta/*"],
+  "include": ["*.ts", "*.tsx", ".meta/*.ts", ".meta/*.tsx"],
   "exclude": ["node_modules"]
 }

common/babel.config.js

@@ -8,5 +8,6 @@
 node_modules/*
 
 # Configuration files
-babel.config.js
-jest.config.js
+.eslintrc.cjs
+babel.config.cjs
+jest.config.cjs

common/jest.config.js common/jest.config.cjs

@@ -0,0 +1,38 @@
+module.exports = {
+  root: true,
+  parserOptions: {
+    tsconfigRootDir: __dirname,
+    project: ['./tsconfig.json'],
+  },
+  overrides: [
+    // Student provided files
+    {
+      files: ['*.ts'],
+      excludedFiles: ['.meta/proof.ci.ts', '.meta/exemplar.ts', '*.test.ts'],
+      extends: '@exercism/eslint-config-typescript',
+    },
+    // Exercism given tests
+    {
+      files: ['*.test.ts'],
+      excludedFiles: ['custom.test.ts'],
+      env: {
+        jest: true,
+      },
+      extends: '@exercism/eslint-config-typescript/maintainers',
+    },
+    // Student provided tests
+    {
+      files: ['custom.test.ts'],
+      env: {
+        jest: true,
+      },
+      extends: '@exercism/eslint-config-typescript',
+    },
+    // Exercism provided files
+    {
+      files: ['.meta/proof.ci.ts', '.meta/exemplar.ts', '*.test.ts'],
+      excludedFiles: ['custom.test.ts'],
+      extends: '@exercism/eslint-config-typescript/maintainers',
+    },
+  ],
+}

common/package.json

@@ -0,0 +1,4 @@
+module.exports = {
+  presets: ['@exercism/babel-preset-typescript'],
+  plugins: [],
+}