wip: migrate to bun

test/isFunction.spec.ts

@@ -0,0 +1,81 @@
+import assert from 'node:assert';
+import lodashStable from 'lodash';
+
+import {
+    slice,
+    asyncFunc,
+    genFunc,
+    arrayViews,
+    objToString,
+    funcTag,
+    falsey,
+    stubFalse,
+    args,
+    symbol,
+    document,
+    realm,
+} from './utils';
+
+import isFunction from '../src/isFunction';
+
+describe('isFunction', () => {
+    it('should return `true` for functions', () => {
+        assert.strictEqual(isFunction(slice), true);
+    });
+
+    it('should return `true` for async functions', () => {
+        assert.strictEqual(isFunction(asyncFunc), typeof asyncFunc === 'function');
+    });
+
+    it('should return `true` for generator functions', () => {
+        assert.strictEqual(isFunction(genFunc), typeof genFunc === 'function');
+    });
+
+    it('should return `true` for the `Proxy` constructor', () => {
+        if (Proxy) {
+            assert.strictEqual(isFunction(Proxy), true);
+        }
+    });
+
+    it('should return `true` for array view constructors', () => {
+        const expected = lodashStable.map(
+            arrayViews,
+            (type) => objToString.call(root[type]) == funcTag,
+        );
+
+        const actual = lodashStable.map(arrayViews, (type) => isFunction(root[type]));
+
+        assert.deepStrictEqual(actual, expected);
+    });
+
+    it('should return `false` for non-functions', () => {
+        const expected = lodashStable.map(falsey, stubFalse);
+
+        const actual = lodashStable.map(falsey, (value, index) =>
+            index ? isFunction(value) : isFunction(),
+        );
+
+        assert.deepStrictEqual(actual, expected);
+
+        assert.strictEqual(isFunction(args), false);
+        assert.strictEqual(isFunction([1, 2, 3]), false);
+        assert.strictEqual(isFunction(true), false);
+        assert.strictEqual(isFunction(new Date()), false);
+        assert.strictEqual(isFunction(new Error()), false);
+        assert.strictEqual(isFunction({ a: 1 }), false);
+        assert.strictEqual(isFunction(1), false);
+        assert.strictEqual(isFunction(/x/), false);
+        assert.strictEqual(isFunction('a'), false);
+        assert.strictEqual(isFunction(symbol), false);
+
+        if (document) {
+            assert.strictEqual(isFunction(document.getElementsByTagName('body')), false);
+        }
+    });
+
+    it('should work with a function from another realm', () => {
+        if (realm.function) {
+            assert.strictEqual(isFunction(realm.function), true);
+        }
+    });
+});