✨ Add isNaN function

docs/.vitepress/config.js

@@ -75,8 +75,9 @@ module.exports = {
               children: members[0]?.members
                 .filter((a) => a.kind === 'Variable')
                 .map(({ name }) => {
-                  const fName = name === 'length_2' ? 'length' : name
-                  console.log(fName)
+                  const fName = name
+                    .replace('length_2', 'length')
+                    .replace('isNaN_2', 'isNaN')
                   return {
                     text: fName,
                     link: `/api/${lowerCase(fName)}/`

docs/api/isnan/index.md

@@ -0,0 +1,30 @@
+<!-- Do not edit this file. It is automatically generated by API Documenter. -->
+
+
+
+## isNaN variable
+
+> This API is provided as a preview for developers and may change based on feedback that we receive. Do not use this API in a production environment.
+> 
+
+Whatever argument is `NaN` or not.
+
+<b>Signature:</b>
+
+```typescript
+isNaN: (val: unknown) => val is number
+```
+
+## Remarks
+
+`NaN` is primitive `number`<!-- -->.
+
+## Example
+
+
+```ts
+isNaN(NaN) // true
+isNaN(100) // false
+
+```
+

scripts/gen-api-docs.ts

@@ -8,7 +8,10 @@ const getFileInfo = (path: string): FileInfo => {
   return {
     path,
     content,
-    name: name.replace(/fonction\.?/, '').replace('length_2', 'length'),
+    name: name
+      .replace(/fonction\.?/, '')
+      .replace('length_2', 'length')
+      .replace('isnan_2', 'isnan'),
     ext
   }
 }
@@ -37,6 +40,9 @@ const run = () => {
       .replace(/\.\/fonction\.(.+)\.md/g, `./$1/`)
       .replace(/length\\_2/g, 'length')
       .replace(/length_2/g, 'length')
+      .replace(/isNaN\\_2/g, 'isNaN')
+      .replace(/isnan_2/g, 'isnan')
+
     // .replace(/\r?\n```/g, '```')
     const to = resolve('docs', 'api', name, 'index.md')
     outputFileSync(to, replaced)

src/isNaN.ts

@@ -0,0 +1,21 @@
+/**
+ * Whatever argument is `NaN` or not.
+ *
+ * @param val - input any value
+ * @returns The result of `Number.isNaN(val)`
+ *
+ * @remarks
+ * `NaN` is primitive `number`.
+ *
+ * @example
+ * ```ts
+ * isNaN(NaN) // true
+ * isNaN(100) // false
+ * ```
+ *
+ * @beta
+ *
+ */
+const isNaN = (val: unknown): val is typeof NaN => Number.isNaN(val)
+
+export { isNaN }

test/isNaN.spec.ts

@@ -0,0 +1,50 @@
+import {
+  BIG1,
+  DATE,
+  EMPTY_ARRAY,
+  EMPTY_OBJECT,
+  EMPTY_STRING,
+  MAP,
+  ONE,
+  SET,
+  SYMBOL,
+  VOID_FN,
+  VOID_PROMISE,
+  WEAK_MAP,
+  WEAK_SET,
+  ZERO
+} from '@test'
+
+import { isNaN } from '@/isNaN'
+describe('isNaN', () => {
+  const table: [unknown, boolean][] = [
+    [NaN, true],
+    [Infinity, false],
+    [-Infinity, false],
+    [null, false],
+    [undefined, false],
+    [ZERO, false],
+    [ONE, false],
+    [EMPTY_STRING, false],
+    ['test', false],
+    [false, false],
+    [true, false],
+    [BIG1, false],
+    [SYMBOL, false],
+    [EMPTY_OBJECT, false],
+    [{ nest: {} }, false],
+    [EMPTY_ARRAY, false],
+    [[[]], false],
+    [MAP, false],
+    [SET, false],
+    [WEAK_MAP, false],
+    [WEAK_SET, false],
+    [VOID_FN, false],
+    [VOID_PROMISE, false],
+    [DATE, false]
+  ]
+
+  it.each(table)('isNaN(%s) -> %s', (val, expected) => {
+    expect(isNaN(val)).toEqual(expected)
+  })
+})