Add JSDoc based types

Author: wooorm

.gitignore

@@ -1,4 +1,5 @@
 .DS_Store
+*.d.ts
 *.log
 coverage/
 node_modules/

index.js

@@ -1,11 +1,44 @@
+/**
+ * @typedef {import('unist').Node} Node
+ * @typedef {import('unist').Parent} Parent
+ */
+
+/**
+ * Function called with a node to produce a new node.
+ *
+ * @callback MapFunction
+ * @param {Node} node Current node being processed
+ * @param {number} [index] Index of `node`, or `null`
+ * @param {Parent} [parent] Parent of `node`, or `null`
+ * @returns {Node} Node to be used in the new tree. Its children are not used: if the original node has children, those are mapped.
+ */
+
+/**
+ * Unist utility to create a new tree by mapping all nodes with the given function.
+ *
+ * @param {Node} tree Tree to map
+ * @param {MapFunction} iteratee Function that returns a new node
+ * @returns {Node} New mapped tree.
+ */
 export function map(tree, iteratee) {
   return preorder(tree, null, null)
 
+  /**
+   * @param {Node} node
+   * @param {number} [index]
+   * @param {Parent} [parent]
+   * @returns {Node}
+   */
   function preorder(node, index, parent) {
     var newNode = Object.assign({}, iteratee(node, index, parent))
 
     if (node.children) {
-      newNode.children = node.children.map(function (child, index) {
+      // @ts-ignore Looks like a parent.
+      newNode.children = node.children.map(function (
+        /** @type {Node} */ child,
+        /** @type {number} */ index
+      ) {
+        // @ts-ignore Looks like a parent.
         return preorder(child, index, node)
       })
     }

package.json

@@ -29,30 +29,35 @@
   "sideEffects": false,
   "type": "module",
   "main": "index.js",
-  "types": "types/index.d.ts",
+  "types": "index.d.ts",
   "files": [
-    "index.js",
-    "types/index.d.ts"
+    "index.d.ts",
+    "index.js"
   ],
-  "dependencies": {},
+  "dependencies": {
+    "@types/unist": "^2.0.0"
+  },
   "devDependencies": {
+    "@types/tape": "^4.0.0",
     "c8": "^7.0.0",
-    "dtslint": "^4.0.0",
     "prettier": "^2.0.0",
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
+    "rimraf": "^3.0.0",
     "tape": "^5.0.0",
+    "type-coverage": "^2.0.0",
     "typescript": "^4.0.0",
     "unist-builder": "^2.0.0",
     "unist-util-is": "^4.0.0",
     "xo": "^0.38.0"
   },
   "scripts": {
+    "prepack": "npm run build && npm run format",
+    "build": "rimraf \"*.d.ts\" && tsc && type-coverage",
     "format": "remark . -qfo && prettier . -w --loglevel warn && xo --fix",
     "test-api": "node test.js",
     "test-coverage": "c8 --check-coverage --branches 100 --functions 100 --lines 100 --statements 100 --reporter lcov node test.js",
-    "test-types": "dtslint types",
-    "test": "npm run format && npm run test-coverage && npm run test-types"
+    "test": "npm run build && npm run format && npm run test-coverage"
   },
   "prettier": {
     "tabWidth": 2,
@@ -73,5 +78,10 @@
     "plugins": [
       "preset-wooorm"
     ]
+  },
+  "typeCoverage": {
+    "atLeast": 100,
+    "detail": true,
+    "strict": true
   }
 }

test.js

@@ -1,3 +1,7 @@
+/**
+ * @typedef {import('unist').Node} Node
+ */
+
 import test from 'tape'
 import u from 'unist-builder'
 import {map} from './index.js'
@@ -16,19 +20,28 @@ test('unist-util-map', function (t) {
   )
 
   t.deepEqual(
+    // @ts-ignore runtime.
     map({}, addValue),
     {value: 'test'},
     'should work when passing an empty object'
   )
 
   t.end()
 
+  /**
+   * @param {Node} node
+   * @returns {Node}
+   */
   function changeLeaf(node) {
     return node.type === 'leaf'
       ? Object.assign({}, node, {value: 'CHANGED'})
       : node
   }
 
+  /**
+   * @param {Node} node
+   * @returns {Node?}
+   */
   function nullLeaf(node) {
     return node.type === 'leaf' ? null : node
   }

tsconfig.json

@@ -0,0 +1,15 @@
+{
+  "include": ["*.js"],
+  "compilerOptions": {
+    "target": "ES2020",
+    "lib": ["ES2020"],
+    "module": "ES2020",
+    "moduleResolution": "node",
+    "allowJs": true,
+    "checkJs": true,
+    "declaration": true,
+    "emitDeclarationOnly": true,
+    "allowSyntheticDefaultImports": true,
+    "skipLibCheck": true
+  }
+}