Add ESLint to project, fix lint issues, set up CI (#12)

* Add ESLint to project, fix lint issues

* Configure CI

.github/workflows/ci.yml

@@ -0,0 +1,27 @@
+name: thoughtbelt CI
+
+on:
+  push:
+    branches: [main]
+  pull_request:
+
+jobs:
+  build:
+    runs-on: ubuntu-latest
+
+    strategy:
+      matrix:
+        node-version: [14.x, 16.x, 18.x, 20.x]
+
+    steps:
+      - uses: actions/checkout@v3
+      - name: Use Node.js ${{ matrix.node-version }}
+        uses: actions/setup-node@v3
+        with:
+          node-version: ${{ matrix.node-version }}
+      - name: Install dependencies
+        run: yarn --frozen-lockfile
+      - name: Run linter
+        run: yarn lint
+      - name: Run tests
+        run: yarn test

bin/belt.js

@@ -4,9 +4,9 @@ import { spawn } from "node:child_process";
 import path from "node:path";
 import { URL, fileURLToPath } from "node:url";
 
-const __dirname = fileURLToPath(new URL(".", import.meta.url));
+const dirname = fileURLToPath(new URL(".", import.meta.url));
 const args = process.argv.slice(2);
 
-spawn("ts-node", [path.join(__dirname, "../src/cli.ts"), ...args], {
+spawn("ts-node", [path.join(dirname, "../src/cli.ts"), ...args], {
   stdio: "inherit",
 });

package.json

@@ -6,16 +6,19 @@
   "type": "module",
   "scripts": {
     "belt": "bin/belt.js",
-    "test": "echo \"Error: no test specified\" && exit 1"
+    "lint": "eslint --max-warnings=0 --ext js,jsx,ts,tsx .",
+    "test": "echo \"testing not yet configured\""
   },
   "bin": {
     "thoughtbelt": "./bin/belt.js"
   },
   "author": "thoughtbot, Inc.",
   "license": "MIT",
   "dependencies": {
+    "@thoughtbot/eslint-config": "thoughtbot/eslint-config#eslint-configs",
     "chalk": "^5.2.0",
     "commander": "^10.0.1",
+    "eslint": "^8.45.0",
     "eta": "^2.1.1",
     "fs-extra": "^11.1.1",
     "inquirer": "^9.2.0",
@@ -28,5 +31,15 @@
     "@types/node": "^18.16.3",
     "@types/react": "^18.2.6",
     "typescript": "^5.0.4"
+  },
+  "eslintConfig": {
+    "extends": [
+      "@thoughtbot/eslint-config/base",
+      "@thoughtbot/eslint-config/prettier",
+      "@thoughtbot/eslint-config/typescript"
+    ],
+    "rules": {
+      "no-console": "off"
+    }
   }
 }

src/commands/typescript.ts

@@ -2,8 +2,8 @@ import chalk from "chalk";
 import { log } from "console";
 import * as eta from "eta";
 import fs from "fs-extra";
-import { fileURLToPath, URL } from "url";
 import path from "path";
+import { fileURLToPath, URL } from "url";
 import addDependency from "../util/addDependency";
 import getProjectDir from "../util/getProjectDir";
 import getProjectType from "../util/getProjectType";
@@ -12,24 +12,25 @@ import writeFile from "../util/writeFile";
 // for manual testing, change this to another name so doesn't conflict
 // with project's tsconfig.json
 const tsConfig = "tsconfig.json";
-const __dirname = fileURLToPath(new URL(".", import.meta.url));
+const dirname = fileURLToPath(new URL(".", import.meta.url));
 
 export default async function addTypescript() {
   const projectDir = await getProjectDir();
 
   if (await fs.exists(path.join(projectDir, tsConfig))) {
     log(
-      chalk.yellow("tsconfig.json already exists, exiting.") +
-        "\nIf you would like to perform a fresh TypeScript install, delete this file and rerun the script.\n"
+      chalk.yellow(
+        "tsconfig.json already exists, exiting.\nIf you would like to perform a fresh TypeScript install, delete this file and rerun the script.\n"
+      )
     );
     return;
   }
 
-  addDependency("typescript @types/react", { dev: true });
+  await addDependency("typescript @types/react", { dev: true });
 
   const projectType = await getProjectType();
   const template = await fs.readFile(
-    path.join(__dirname, "templates", "tsconfig.json.eta")
+    path.join(dirname, "templates", "tsconfig.json.eta")
   );
   const fileContents = eta.render(template.toString(), {
     expo: projectType === "expo-bare" || projectType === "expo-managed",
@@ -40,7 +41,8 @@ export default async function addTypescript() {
   });
 
   log(
-    chalk.green("\n🎉 TypeScript successfully configured") +
-      "\nConsider renaming your existing JS files as .ts or .tsx.\n"
+    chalk.green(
+      "\n🎉 TypeScript successfully configured\nConsider renaming your existing JS files as .ts or .tsx.\n"
+    )
   );
 }

src/types.ts

@@ -0,0 +1,9 @@
+export type PackageJson = {
+  [k: string]: unknown;
+  dependencies?: {
+    [k: string]: unknown;
+  };
+  devDependencies?: {
+    [k: string]: unknown;
+  };
+};

src/util/addDependency.ts

@@ -1,7 +1,7 @@
+import { exec } from "child_process";
 import * as fs from "fs-extra";
-import getProjectDir from "./getProjectDir";
 import * as path from "path";
-import { exec } from "child_process";
+import getProjectDir from "./getProjectDir";
 
 export default async function addDependency(deps: string, { dev = false }) {
   const isYarn = await fs.exists(path.join(await getProjectDir(), "yarn.lock"));

src/util/getProjectDir.ts

@@ -10,6 +10,7 @@ export default async function getProjectDir(
   do {
     try {
       // This will throw if there is no package.json in the directory
+      // eslint-disable-next-line no-await-in-loop
       await fs.readFile(path.join(dir, "package.json"));
 
       // if didn't throw, package.json exists, return dir

src/util/getProjectType.ts

@@ -4,8 +4,9 @@ type ProjectType = "expo-bare" | "expo-managed" | "react-native";
 
 export default async function getProjectType(): Promise<ProjectType> {
   const packageJson = await readPackageJson();
-  const hasExpo = packageJson.dependencies?.hasOwnProperty("expo");
-  const hasReactNativeUnimodules = packageJson.dependencies?.hasOwnProperty(
+  const hasExpo = hasProperty(packageJson.dependencies, "expo");
+  const hasReactNativeUnimodules = hasProperty(
+    packageJson.dependencies,
     "react-native-unimodules"
   );
   if (hasExpo) {
@@ -14,3 +15,10 @@ export default async function getProjectType(): Promise<ProjectType> {
 
   return "react-native";
 }
+
+function hasProperty(
+  object: Record<string, unknown> | undefined,
+  property: string
+) {
+  return Object.prototype.hasOwnProperty.call(object, property);
+}

src/util/readPackageJson.ts

@@ -1,9 +1,10 @@
+import fs from "fs-extra";
 import path from "path";
+import { PackageJson } from "../types";
 import getProjectDir from "./getProjectDir";
-import fs from "fs-extra";
 
 export default async function readPackageJson() {
   const rootDir = await getProjectDir();
   const pkg = await fs.readFile(path.join(rootDir, "package.json"));
-  return JSON.parse(pkg.toString());
+  return JSON.parse(pkg.toString()) as PackageJson;
 }

src/util/writeFile.ts

@@ -12,7 +12,7 @@ export default async function writeFile(
   { format = false }: Options = {}
 ) {
   console.log(chalk.bold(`🔨 Creating ${filePath}`));
-  fs.writeFile(filePath, contents);
+  await fs.writeFile(filePath, contents);
 
   if (format) {
     await formatFile(filePath);