Add JSDoc based types

Author: wooorm

.gitignore

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

index.js

@@ -1,15 +1,41 @@
+/**
+ * @typedef {import('unist').Node} Node
+ * @typedef {Node & {position: undefined}} NodeWithUndefinedPosition
+ * @typedef {Omit<Node, 'position'>} NodeWithoutPosition
+ */
+
 import {visit} from 'unist-util-visit'
 
-export function removePosition(node, force) {
-  visit(node, remove)
+export const removePosition =
+  /**
+   * @type {(
+   *   ((tree: Node, force?: false) => NodeWithUndefinedPosition) &
+   *   ((tree: Node, force: true) => NodeWithoutPosition)
+   * )}
+   */
+  (
+    /**
+     * Utility to remove positions from a tree
+     *
+     * @param {Node} node the unist tree
+     * @param {boolean} [force=false] if `force` is given, uses `delete`, otherwise, sets positions to `undefined`.
+     * @returns {NodeWithUndefinedPosition}
+     */
+    function (node, force) {
+      visit(node, remove)
 
-  return node
+      // @ts-ignore hush TS, we know what we’re doing.
+      return node
 
-  function remove(node) {
-    if (force) {
-      delete node.position
-    } else {
-      node.position = undefined
+      /**
+       * @param {Node} node the unist tree
+       */
+      function remove(node) {
+        if (force) {
+          delete node.position
+        } else {
+          node.position = undefined
+        }
+      }
     }
-  }
-}
+  )

index.test-d.ts

@@ -0,0 +1,21 @@
+import {expectType} from 'tsd'
+import {Node} from 'unist'
+import remark from 'remark'
+import {
+  removePosition,
+  NodeWithUndefinedPosition,
+  NodeWithoutPosition
+} from './index.js'
+
+const tree: Node = remark().parse(
+  'Some _emphasis_, **importance**, and `code`.'
+)
+
+expectType<NodeWithUndefinedPosition>(removePosition(tree))
+expectType<NodeWithUndefinedPosition>(removePosition(tree, false))
+expectType<NodeWithoutPosition>(removePosition(tree, true))
+
+// Used as a plugin
+void remark()
+  .use(() => (tree: Node) => removePosition(tree))
+  .process('Some _emphasis_, **importance**, and `code`.')

package.json

@@ -28,29 +28,37 @@
   "sideEffects": false,
   "type": "module",
   "main": "index.js",
-  "types": "types/index.d.ts",
+  "types": "index.d.ts",
   "files": [
-    "types/index.d.ts",
+    "index.d.ts",
     "index.js"
   ],
   "dependencies": {
+    "@types/unist": "^2.0.0",
     "unist-util-visit": "^3.0.0"
   },
   "devDependencies": {
+    "@types/tape": "^4.0.0",
     "c8": "^7.0.0",
     "prettier": "^2.0.0",
     "remark": "^13.0.0",
     "remark-cli": "^9.0.0",
     "remark-preset-wooorm": "^8.0.0",
+    "rimraf": "^3.0.0",
     "tape": "^5.0.0",
+    "tsd": "^0.14.0",
+    "type-coverage": "^2.0.0",
+    "typescript": "^4.0.0",
     "unist-builder": "^3.0.0",
     "xo": "^0.38.0"
   },
   "scripts": {
+    "prepack": "npm run build && npm run format",
+    "build": "rimraf \"*.d.ts\" && tsc && tsd && 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": "npm run format && npm run test-coverage"
+    "test": "npm run build && npm run format && npm run test-coverage"
   },
   "prettier": {
     "tabWidth": 2,
@@ -65,14 +73,16 @@
     "rules": {
       "no-var": "off",
       "prefer-arrow-callback": "off"
-    },
-    "ignores": [
-      "types/"
-    ]
+    }
   },
   "remarkConfig": {
     "plugins": [
       "preset-wooorm"
     ]
+  },
+  "typeCoverage": {
+    "atLeast": 100,
+    "detail": true,
+    "strict": true
   }
 }

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
+  }
+}