wip: code formatting nits continued

test/sortBy.spec.js

@@ -0,0 +1,99 @@
+import lodashStable from 'lodash';
+import sortBy from '../src/sortBy';
+
+describe('sortBy', () => {
+    const objects = [
+        { a: 'x', b: 3 },
+        { a: 'y', b: 4 },
+        { a: 'x', b: 1 },
+        { a: 'y', b: 2 },
+    ];
+
+    it('should sort in ascending order by `iteratee`', () => {
+        const actual = lodashStable.map(
+            sortBy(objects, (object) => object.b),
+            'b',
+        );
+
+        expect(actual, [1, 2, 3).toEqual(4]);
+    });
+
+    it('should use `_.identity` when `iteratee` is nullish', () => {
+        const array = [3, 2, 1];
+        const values = [, null, undefined];
+        const expected = lodashStable.map(values, lodashStable.constant([1, 2, 3]));
+
+        const actual = lodashStable.map(values, (value, index) =>
+            index ? sortBy(array, value) : sortBy(array),
+        );
+
+        expect(actual).toEqual(expected);
+    });
+
+    it('should work with `_.property` shorthands', () => {
+        const actual = lodashStable.map(sortBy(objects.concat(undefined), 'b'), 'b');
+        expect(actual, [1, 2, 3, 4).toEqual(undefined]);
+    });
+
+    it('should work with an object for `collection`', () => {
+        const actual = sortBy({ a: 1, b: 2, c: 3 }, Math.sin);
+        expect(actual, [3, 1).toEqual(2]);
+    });
+
+    it('should move `NaN`, nullish, and symbol values to the end', () => {
+        const symbol1 = Symbol ? Symbol('a') : null;
+        const symbol2 = Symbol ? Symbol('b') : null;
+        let array = [NaN, undefined, null, 4, symbol1, null, 1, symbol2, undefined, 3, NaN, 2];
+        let expected = [1, 2, 3, 4, symbol1, symbol2, null, null, undefined, undefined, NaN, NaN];
+
+        expect(sortBy(array)).toEqual(expected);
+
+        array = [NaN, undefined, symbol1, null, 'd', null, 'a', symbol2, undefined, 'c', NaN, 'b'];
+        expected = [
+            'a',
+            'b',
+            'c',
+            'd',
+            symbol1,
+            symbol2,
+            null,
+            null,
+            undefined,
+            undefined,
+            NaN,
+            NaN,
+        ];
+
+        expect(sortBy(array)).toEqual(expected);
+    });
+
+    it('should treat number values for `collection` as empty', () => {
+        expect(sortBy(1)).toEqual([]);
+    });
+
+    it('should coerce arrays returned from `iteratee`', () => {
+        const actual = sortBy(objects, (object) => {
+            const result = [object.a, object.b];
+            result.toString = function () {
+                return String(this[0]);
+            };
+            return result;
+        });
+
+        expect(actual, [objects[0], objects[2], objects[1]).toEqual(objects[3]]);
+    });
+
+    it('should work as an iteratee for methods like `_.map`', () => {
+        const actual = lodashStable.map(
+            [
+                [2, 1, 3],
+                [3, 2, 1],
+            ],
+            sortBy,
+        );
+        assert.deepStrictEqual(actual, [
+            [1, 2, 3],
+            [1, 2, 3],
+        ]);
+    });
+});