Change to only accept valid nodes, strings

Author: wooorm

Diff for: index.js

@@ -1,8 +1,16 @@
+/**
+ * @typedef {import('hast').Nodes} Nodes
+ */
+
+// HTML whitespace expression.
+// See <https://infra.spec.whatwg.org/#ascii-whitespace>.
+const re = /[ \t\n\f\r]/g
+
 /**
  * Check if the given value is *inter-element whitespace*.
  *
- * @param {unknown} thing
- *   Thing to check (typically `Node` or `string`).
+ * @param {Nodes | string} thing
+ *   Thing to check (`Node` or `string`).
  * @returns {boolean}
  *   Whether the `value` is inter-element whitespace (`boolean`): consisting of
  *   zero or more of space, tab (`\t`), line feed (`\n`), carriage return
@@ -11,15 +19,17 @@
  *   checked.
  */
 export function whitespace(thing) {
-  /** @type {string} */
-  const value =
-    // @ts-expect-error looks like a node.
-    thing && typeof thing === 'object' && thing.type === 'text'
-      ? // @ts-expect-error looks like a text.
-        thing.value || ''
-      : thing
+  return typeof thing === 'object'
+    ? thing.type === 'text'
+      ? empty(thing.value)
+      : false
+    : empty(thing)
+}
 
-  // HTML whitespace expression.
-  // See <https://infra.spec.whatwg.org/#ascii-whitespace>.
-  return typeof value === 'string' && value.replace(/[ \t\n\f\r]/g, '') === ''
+/**
+ * @param {string} value
+ * @returns {boolean}
+ */
+function empty(value) {
+  return value.replace(re, '') === ''
 }

Diff for: package.json

@@ -34,6 +34,9 @@
     "index.d.ts",
     "index.js"
   ],
+  "dependencies": {
+    "@types/hast": "^3.0.0"
+  },
   "devDependencies": {
     "@types/node": "^20.0.0",
     "c8": "^8.0.0",

Diff for: readme.md

@@ -66,6 +66,7 @@ import {whitespace} from 'hast-util-whitespace'
 whitespace({
   type: 'element',
   tagName: 'div',
+  properties: {},
   children: []
 }) // => false
 
@@ -91,8 +92,8 @@ Check if the given value is [*inter-element whitespace*][spec].
 
 ###### Parameters
 
-*   `thing` (`unknown`, optional)
-    — thing to check (typically [`Node`][node] or `string`)
+*   `thing` ([`Node`][node] or `string`, optional)
+    — thing to check
 
 ###### Returns
 

Diff for: test.js

@@ -10,11 +10,8 @@ test('whitespace', () => {
     'should expose the public api'
   )
 
-  // @ts-expect-error: runtime.
-  assert.equal(whitespace(), false, 'should return `false` without node')
-
   assert.equal(
-    whitespace({type: 'element', tagName: 'div'}),
+    whitespace({type: 'comment', value: 'asd'}),
     false,
     'should return `false` without text'
   )
@@ -31,12 +28,6 @@ test('whitespace', () => {
     'should return `true` for inter-element white-space'
   )
 
-  assert.equal(
-    whitespace({type: 'text'}),
-    true,
-    'should return `true` for `text` without value'
-  )
-
   assert.equal(
     whitespace(' \v'),
     false,