wip: migrate to bun

test/head.spec.ts

@@ -0,0 +1,66 @@
+import assert from 'node:assert';
+import lodashStable from 'lodash';
+import { arrayProto, LARGE_ARRAY_SIZE } from './utils';
+import head from '../src/head';
+import first from '../src/first';
+
+describe('head', () => {
+    const array = [1, 2, 3, 4];
+
+    it('should return the first element', () => {
+        assert.strictEqual(head(array), 1);
+    });
+
+    it('should return `undefined` when querying empty arrays', () => {
+        arrayProto[0] = 1;
+        assert.strictEqual(head([]), undefined);
+        arrayProto.length = 0;
+    });
+
+    it('should work as an iteratee for methods like `_.map`', () => {
+        const array = [
+                [1, 2, 3],
+                [4, 5, 6],
+                [7, 8, 9],
+            ],
+            actual = lodashStable.map(array, head);
+
+        assert.deepStrictEqual(actual, [1, 4, 7]);
+    });
+
+    it('should be aliased', () => {
+        assert.strictEqual(first, head);
+    });
+
+    it('should return an unwrapped value when implicitly chaining', () => {
+        const wrapped = _(array);
+        assert.strictEqual(wrapped.head(), 1);
+        assert.strictEqual(wrapped.first(), 1);
+    });
+
+    it('should return a wrapped value when explicitly chaining', () => {
+        const wrapped = _(array).chain();
+        assert.ok(wrapped.head() instanceof _);
+        assert.ok(wrapped.first() instanceof _);
+    });
+
+    it('should not execute immediately when explicitly chaining', () => {
+        const wrapped = _(array).chain();
+        assert.strictEqual(wrapped.head().__wrapped__, array);
+        assert.strictEqual(wrapped.first().__wrapped__, array);
+    });
+
+    it('should work in a lazy sequence', () => {
+        const largeArray = lodashStable.range(LARGE_ARRAY_SIZE),
+            smallArray = array;
+
+        lodashStable.each(['head', 'first'], (methodName) => {
+            lodashStable.times(2, (index) => {
+                const array = index ? largeArray : smallArray,
+                    actual = _(array).filter(isEven)[methodName]();
+
+                assert.strictEqual(actual, _[methodName](_.filter(array, isEven)));
+            });
+        });
+    });
+});