feat(scripts): add depcheck script and API (/api/depcheck)

Author: daniel-reed

.depcheckrc.json

@@ -0,0 +1,13 @@
+{
+  "specials": ["babel", "bin", "eslint", "jest", "lint-staged", "tslint"],
+  "ignoreMatches": [
+    "@types/*",
+    "concurrently",
+    "doctoc",
+    "eslint-config-*",
+    "eslint-plugin-*",
+    "jest-github-actions-reporter",
+    "lint-staged",
+    "tslib"
+  ]
+}

README.md

@@ -39,6 +39,7 @@
     - [Prettier](#prettier)
     - [Jest](#jest)
     - [Semantic Release](#semantic-release)
+    - [Depcheck](#depcheck)
     - [Lint Staged](#lint-staged)
   - [Source Control Hooks](#source-control-hooks)
     - [Husky Example](#husky-example)
@@ -167,6 +168,31 @@ module.exports = {
 }
 ```
 
+#### Depcheck
+
+> ℹ️ The `hoverBabel` special requires NODE_PATH to be defined to resolve the
+> babel config file
+
+Or, for depcheck in `.depcheckrc.json'`:
+
+```json
+{
+  "specials": [
+    "babel",
+    "bin",
+    "jest",
+    [
+      "hoverBabel",
+      {
+        "config": "babel.config.js",
+        "env": "development"
+      }
+    ]
+  ],
+  "ignoreMatches": ["types/*"]
+}
+```
+
 #### Lint Staged
 
 Or, for lint-staged (used in `pre-commit` script) in `lint-staged.config.js`:

api/depcheck.d.ts

@@ -0,0 +1 @@
+export * from '../dist/api/depcheck'

api/depcheck.js

@@ -0,0 +1 @@
+module.exports = require('../dist/api/depcheck')

package.json

@@ -19,6 +19,7 @@
     "build:types": "tsc -p src/",
     "ci-after-success": "node src ci-after-success",
     "commit": "node src commit",
+    "depcheck": "node src depcheck",
     "format": "node src format",
     "lint": "node src lint",
     "prepublishOnly": "yarn build",
@@ -53,6 +54,11 @@
     "@commitlint/config-conventional": "^16.2.1",
     "@commitlint/prompt": "^16.1.0",
     "@types/jest": "^27.0.2",
+    "@types/lodash.has": "^4.5.6",
+    "@types/mkdirp": "^1.0.2",
+    "@types/node": ">=17.x",
+    "@types/rimraf": "^3.0.2",
+    "@types/which": "^2.0.1",
     "@typescript-eslint/eslint-plugin": "^5.13.0",
     "@typescript-eslint/parser": "^5.13.0",
     "arrify": "^2.0.1",
@@ -63,7 +69,6 @@
     "cross-spawn": "^7.0.1",
     "doctoc": "^2.1.0",
     "eslint": "^8.8.0",
-    "@types/node": ">=17.x",
     "eslint-config-airbnb": "19.0.0",
     "eslint-config-airbnb-typescript": "^16.1.0",
     "eslint-config-prettier": "^8.3.0",
@@ -126,6 +131,7 @@
     "@babel/preset-env": "^7.16.11",
     "@types/cross-spawn": "^6.0.2",
     "babel-jest": "^27.2.4",
+    "depcheck": "^1.4.3",
     "eslint-config-kentcdodds": "^20.0.1",
     "husky": "^7.0.4",
     "jest-in-case": "^1.0.2",

src/__tests__/__snapshots__/index.js.snap

@@ -24,6 +24,7 @@ Available Scripts:
   ci-after-success
   commit-msg
   commit
+  depcheck
   format
   lint
   pre-commit

src/api/depcheck/depcheck.js

@@ -0,0 +1,111 @@
+const fs = require('fs')
+const depcheck = require('depcheck')
+const hoverSpecials = require('./specials')
+const {hasFile, uniq} = require('../../utils')
+
+/**
+ * @typedef Config
+ * @property {boolean} [ignoreBinPackage]
+ * @property {boolean} [skipMissing]
+ * @property {string[]} [ignorePatterns]
+ * @property {string[]} [ignoreMatches]
+ * @property {string[]} [parsers]
+ * @property {string[]} [detectors]
+ * @property {string[]} [specials]
+ */
+
+/**
+ * @param {string} configPath
+ * @return {Config}
+ */
+const resolveConfig = configPath => {
+  let loadedOptions = {}
+  if (!!configPath && hasFile(configPath)) {
+    loadedOptions = JSON.parse(fs.readFileSync(configPath, {encoding: 'utf8'}))
+  }
+
+  return loadedOptions
+}
+
+/**
+ *
+ * @param {{[key: string]: string}} parsers
+ * @return {{[key: string]: depcheck.Parser}}
+ */
+const resolveParsers = parsers => {
+  /** @var {{[key: string]: depcheck.Parser}} resolvedParsers */
+  const resolvedParsers = {}
+  Object.keys(parsers).forEach(key => {
+    // @ts-ignore
+    if (depcheck.parser[parsers[key]]) {
+      // @ts-ignore
+      resolvedParsers[key] = depcheck.parser[parsers[key]]
+    }
+  })
+
+  // @ts-ignore
+  return resolvedParsers
+}
+
+/**
+ *
+ * @param {string[]}detectors
+ * @return {depcheck.Detector[]}
+ */
+const resolveDetectors = detectors => {
+  return uniq(
+    detectors.map(detector => {
+      // @ts-ignore
+      if (depcheck.detector[detector]) {
+        //@ts-ignore
+        return depcheck.detector[detector]
+      }
+      throw new Error(`Undefined detector ${detector}`)
+    }),
+  )
+}
+
+/**
+ *
+ * @param {*[]} specials
+ * @return {depcheck.Parser[]}
+ */
+const resolveSpecials = specials => {
+  return uniq(
+    specials.map(special => {
+      if (typeof special === 'string') {
+        // @ts-ignore
+        if (depcheck.special[special]) {
+          // @ts-ignore
+          return depcheck.special[special]
+        }
+
+        // @ts-ignore
+        if (hoverSpecials[special] && hoverSpecials[special].special) {
+          // @ts-ignore
+          return hoverSpecials[special].special
+        }
+      }
+
+      if (Array.isArray(special)) {
+        const name = special[0] || ''
+        const config = special[1] || {}
+
+        // @ts-ignore
+        if (hoverSpecials[name] && hoverSpecials[name].configure) {
+          // @ts-ignore
+          return hoverSpecials[name].configure(config)
+        }
+      }
+
+      throw new Error(`Undefined special ${special}`)
+    }),
+  )
+}
+
+module.exports = {
+  resolveConfig,
+  resolveDetectors,
+  resolveParsers,
+  resolveSpecials,
+}

src/api/depcheck/index.js

@@ -0,0 +1,4 @@
+module.exports = {
+  depcheck: require('./depcheck'),
+  specials: require('./specials'),
+}

src/api/depcheck/specials/babel.js

@@ -0,0 +1,71 @@
+const path = require('path')
+
+/**
+ *
+ * @param {string | unknown[]} preset
+ * @return {string}
+ */
+const babelDependencyToName = preset => {
+  if (typeof preset === 'string') return preset
+  if (Array.isArray(preset) && typeof preset[0] === 'string') return preset[0]
+  return ''
+}
+
+/**
+ * Configures a special babel parser. Enables detection of babel plugins and presets when they are defined in js files
+ * (e.g. babel.config.js)
+ *
+ * @param {Object} options
+ * @param {string} options.config
+ * @param {string} options.env
+ * @return {function(string, *, string): string[]}
+ */
+const configure = options => {
+  const getBabelConfig = require(options.config)
+  const babelConfig = getBabelConfig({
+    env: (/** @type {string[]} */ envs) => envs.includes(options.env),
+  })
+
+  /**
+   * @param {string} filePath
+   * @param {*} _
+   * @param {string} dir
+   * @return {string[]}
+   */
+  const detectBabelPreset = (filePath, _, dir) => {
+    if (filePath !== path.join(dir, options.config)) {
+      return []
+    }
+
+    const presets = babelConfig.presets || []
+    return presets
+      .map(babelDependencyToName)
+      .filter((/** @type {string} */ name) => !!name)
+  }
+
+  /**
+   * @param {string} filePath
+   * @param {*} _
+   * @param {string} dir
+   * @return {string[]}
+   */
+  const detectBabelPlugin = (filePath, _, dir) => {
+    if (filePath !== path.join(dir, options.config)) {
+      return []
+    }
+
+    const plugins = babelConfig.plugins || []
+    return plugins
+      .map(babelDependencyToName)
+      .filter((/** @type {string} */ name) => !!name)
+  }
+
+  return (filePath, _, dir) => [
+    ...detectBabelPreset(filePath, _, dir),
+    ...detectBabelPlugin(filePath, _, dir),
+  ]
+}
+
+module.exports = {
+  configure,
+}

src/api/depcheck/specials/index.js

@@ -0,0 +1,3 @@
+module.exports = {
+  hoverBabel: require('./babel'),
+}