Refactor types

Author: wooorm

index.js

@@ -23,23 +23,26 @@ module.exports = find
 /**
  * Unist node finder utility.
  *
- * @param tree
- *   Node to search.
- * @param condition
- *   Condition used to test each node.
- * @returns
- *   The first node that matches condition, or undefined if no node matches.
- * @type {<V extends Node>(tree: Node, condition: TestStr | TestObj | TestFn) => V | undefined}
+ * @template {Node} V
+ *   Node to search for.
+ * @param {Node} tree
+ *   Tree to search in.
+ * @param {TestStr | TestObj | TestFn} condition
+ *   Condition used to test each node, which matches `V`.
+ * @returns {V | undefined}
+ *   The first node that matches condition, or `undefined` if no node matches.
  */
 function find(tree, condition) {
   if (!tree) throw new Error('unist-util-find requires a tree to search')
   if (!condition) throw new Error('unist-util-find requires a condition')
 
   const predicate = iteratee(condition)
+  /** @type {V | undefined} */
   let result
 
   visit(tree, function (node) {
     if (predicate(node)) {
+      // @ts-expect-error: assume `predicate` checks for `V`.
       result = node
       return false
     }

package.json

@@ -11,11 +11,11 @@
   ],
   "sideEffects": false,
   "scripts": {
-    "prepack": "npm run build",
+    "prepack": "npm run build && npm run format",
+    "build": "tsc --build --clean && tsc --build && type-coverage",
     "format": "prettier . -w --loglevel warn && xo --fix",
     "test-api": "node --conditions development test.js",
-    "test": "npm run format && npm run test-api",
-    "build": "tsc"
+    "test": "npm run build && npm run format && npm run test-api"
   },
   "type": "commonjs",
   "keywords": [
@@ -33,11 +33,14 @@
   "license": "MIT",
   "devDependencies": {
     "@types/lodash.iteratee": "^4.7.7",
+    "@types/mdast": "^3.0.0",
+    "@types/tape": "^5.0.0",
     "@types/unist": "^2.0.6",
     "prettier": "^2.0.0",
     "remark": "^13.0.0",
     "tape": "^5.3.1",
-    "typescript": "^4.6.4",
+    "type-coverage": "^2.0.0",
+    "typescript": "^5.0.0",
     "xo": "^0.54.0"
   },
   "dependencies": {
@@ -52,6 +55,12 @@
     "trailingComma": "none",
     "useTabs": false
   },
+  "typeCoverage": {
+    "atLeast": 100,
+    "detail": true,
+    "ignoreCatch": true,
+    "strict": true
+  },
   "xo": {
     "rules": {
       "unicorn/prefer-module": "off"

test.js

@@ -1,30 +1,42 @@
+/**
+ * @typedef {import('mdast').Root} Root
+ */
+
+const assert = require('node:assert/strict')
 const test = require('tape')
 const remark = require('remark')
 const find = require('./index.js')
 
 test('unist-find', function (t) {
-  const tree = remark().parse('Some _emphasis_, **strongness**, and `code`.')
+  const tree = /** @type {Root} */ (
+    remark().parse('Some _emphasis_, **strongness**, and `code`.')
+  )
+  assert(tree.type === 'root')
+  const paragraph = tree.children[0]
+  assert(paragraph.type === 'paragraph')
 
   t.throws(function () {
+    // @ts-expect-error: check that an error is thrown at runtime.
     find()
   }, 'should fail without tree')
 
   t.throws(function () {
+    // @ts-expect-error: check that an error is thrown at runtime.
     find(tree)
   }, 'should fail without condition')
 
   t.test('should find with string condition', function (st) {
     const result = find(tree, 'value')
 
-    st.equal(result, tree.children[0].children[0])
+    st.equal(result, paragraph.children[0])
 
     st.end()
   })
 
   t.test('should find with object condition', function (st) {
     const result = find(tree, {type: 'emphasis'})
 
-    st.equal(result, tree.children[0].children[1])
+    st.equal(result, paragraph.children[1])
 
     st.end()
   })
@@ -34,7 +46,7 @@ test('unist-find', function (t) {
       return node.type === 'inlineCode'
     })
 
-    st.equal(result, tree.children[0].children[5])
+    st.equal(result, paragraph.children[5])
 
     st.end()
   })

tsconfig.json

@@ -1,15 +1,15 @@
 {
   "compilerOptions": {
-    "target": "ES2020",
-    "module": "ES2020",
-    "moduleResolution": "node",
-    "strict": true,
-    "allowJs": true,
     "checkJs": true,
-    "allowSyntheticDefaultImports": true,
+    "customConditions": ["development"],
     "declaration": true,
     "emitDeclarationOnly": true,
-    "skipLibCheck": true
+    "exactOptionalPropertyTypes": true,
+    "lib": ["es2020"],
+    "module": "node16",
+    "strict": true,
+    "target": "es2020"
   },
-  "include": ["index.js"]
+  "exclude": ["coverage/", "node_modules/"],
+  "include": ["**/*.js"]
 }