Added unit tests

Author: jherax

README.md

@@ -118,7 +118,7 @@ sortBy(arr);
  */
 ```
 
-### Sorting DESC
+### Sorting DESC: numbers
 
 ```javascript
 let arr = [5, 1, 8, 0, 3, 7, 10, 4, 3, 8];
@@ -130,7 +130,7 @@ sortBy(arr, n => -n);
  */
 ```
 
-### Sorting DESC date-strings as `Date`
+### Sorting DESC: date-strings as `Date`
 
 ```javascript
 let arr = ["1983/03/06", "1980/12/24", "1985/08/31", "1983/03/05"];
@@ -142,12 +142,12 @@ sortBy(arr, (s) => -new Date(s));
  */
 ```
 
-### Sorting DESC strings
+### Sorting DESC: strings
 
 Because we use the minus **(-)** symbol to specify a descending order,
-it will produce a `NaN` value if it is used with a `String` element.
-That's why the flag **`"desc:"`** (not case sensitive) is prefixed
-to the string element in the `parser` callback.
+it would produce a `NaN` value if used with a `String` value.
+So the flag **`"desc:"`** (not case sensitive) is prefixed
+to the string value in the `parser` callback.
 
 ```javascript
 var arr = ['único', 'cosas', 'Árbol', 'fútbol', 'algo'];
@@ -158,14 +158,15 @@ sortBy(arr, item => 'desc:' + item);
  * ["único", "fútbol", "cosas", "Árbol", "algo"]
  */
 
+// sorting ASC: accented words
 sortBy(arr);
 /**
  * expected:
  * ["algo", "Árbol", "cosas", "fútbol", "único"]
  */
 ```
 
-### Sorting accented words by @text
+### Sorting ASC: accented words by @text
 
 ```javascript
 var arr = [
@@ -186,25 +187,25 @@ sortBy(arr, item => item.text);
  */
 ```
 
-### Sorting DESC by @a, after ASC by @d (as Date)
+### Sorting DESC by @id, after ASC by @dob (as Date)
 
 ```javascript
 let arr = [
-  { a: 8, d: "1985/08/31" },
-  { a: 2, d: "1980/12/24" },
-  { a: 5, d: "1983/03/06" },
-  { a: 8, d: "1983/03/06" }
+  { id: 8, dob: '1985/08/31' },
+  { id: 2, dob: '1980/12/24' },
+  { id: 5, dob: '1983/03/06' },
+  { id: 8, dob: '1983/03/06' }
 ];
 
-sortBy(arr, (o) => [-o.a, new Date(o.d)]);
+sortBy(arr, (o) => [-o.id, new Date(o.dob)]);
 
 /**
  * expected:
  * [
- *   { a: 8, d: "1983/03/06" },
- *   { a: 8, d: "1985/08/31" },
- *   { a: 5, d: "1983/03/06" },
- *   { a: 2, d: "1980/12/24" }
+ *   { id: 8, dob: "1983/03/06" },
+ *   { id: 8, dob: "1985/08/31" },
+ *   { id: 5, dob: "1983/03/06" },
+ *   { id: 2, dob: "1980/12/24" }
  * ]
  */
 ```
@@ -213,13 +214,13 @@ sortBy(arr, (o) => [-o.a, new Date(o.d)]);
 
 ```javascript
 let arr = [
-  { id: 4, name: "Pedro" },
-  { id: 6, name: "Lucía" },
-  { id: 7, name: "paco" },
-  { id: 3, name: "luis" }
+  { id: 4, name: 'Pedro' },
+  { id: 6, name: 'Lucía' },
+  { id: 7, name: 'paco' },
+  { id: 3, name: 'luis' }
 ];
 
-sortBy(arr, item => "DESC:" + item.name);
+sortBy(arr, item => `DESC:${item.name}`);
 
 /**
  * expected:
@@ -232,25 +233,25 @@ sortBy(arr, item => "DESC:" + item.name);
  */
 ```
 
-### Sorting ASC by @name, after DESC by @age, after ASC by @a
+### Sorting ASC by @name, after DESC by @age, after ASC by @id
 
 ```javascript
 let arr = [
-  { a: 9, age: 26, name: "pedro" },
-  { a: 6, age: 21, name: "Pedro" },
-  { a: 7, age: 26, name: "Maria" },
-  { a: 2, age: 26, name: "maría" }
+  { id: 9, age: 26, name: 'pedro' },
+  { id: 6, age: 21, name: 'Pedro' },
+  { id: 7, age: 26, name: 'Maria' },
+  { id: 2, age: 26, name: 'maría' }
 ];
 
-sortBy(arr, item => [item.name, -item.age, item.a]);
+sortBy(arr, item => [item.name, -item.age, item.id]);
 
 /**
  * expected:
  * [
- *   { a: 2, age: 26, name: "maría" },
- *   { a: 7, age: 26, name: "Maria" },
- *   { a: 9, age: 26, name: "pedro" },
- *   { a: 6, age: 21, name: "Pedro" }
+ *   { id: 2, age: 26, name: "maría" },
+ *   { id: 7, age: 26, name: "Maria" },
+ *   { id: 9, age: 26, name: "pedro" },
+ *   { id: 6, age: 21, name: "Pedro" }
  * ]
  */
 ```

test/sorting-asc-by-text.js

@@ -0,0 +1,19 @@
+import test from 'ava';
+import sortBy from '../dist/sort-by.min';
+
+test('Sorting ASC: accented words by @text', async (t) => {
+  const arr = [
+    {id: 10, text: 'Woche'},
+    {id: 20, text: 'wöchentlich'},
+    {id: 30, text: 'wäre'},
+  ];
+
+  const expected = [
+    {id: 30, text: 'wäre'},
+    {id: 10, text: 'Woche'},
+    {id: 20, text: 'wöchentlich'},
+  ];
+
+  sortBy(arr, item => item.text);
+  t.deepEqual(arr, expected);
+});

test/sorting-asc.js renamed to test/sorting-asc-numbers.js

@@ -0,0 +1,10 @@
+import test from 'ava';
+import sortBy from '../dist/sort-by.min';
+
+test('Sorting ASC: strings', async (t) => {
+  const arr = ['único', 'cosas', 'Árbol', 'fútbol', 'algo'];
+  const expected = ['algo', 'Árbol', 'cosas', 'fútbol', 'único'];
+
+  sortBy(arr);
+  t.deepEqual(arr, expected);
+});

test/sorting-asc-strings.js

@@ -0,0 +1,21 @@
+import test from 'ava';
+import sortBy from '../dist/sort-by.min';
+
+test('Sorting DESC by @id, after ASC by @dob (as Date)', async (t) => {
+  const arr = [
+    {id: 8, dob: '1985/08/31'},
+    {id: 2, dob: '1980/12/24'},
+    {id: 5, dob: '1983/03/06'},
+    {id: 8, dob: '1983/03/06'},
+  ];
+
+  const expected = [
+    {id: 8, dob: '1983/03/06'},
+    {id: 8, dob: '1985/08/31'},
+    {id: 5, dob: '1983/03/06'},
+    {id: 2, dob: '1980/12/24'},
+  ];
+
+  sortBy(arr, o => [-o.id, new Date(o.dob)]);
+  t.deepEqual(arr, expected);
+});

test/sorting-by-id-dob.js

@@ -0,0 +1,21 @@
+import test from 'ava';
+import sortBy from '../dist/sort-by.min';
+
+test('Sorting ASC by @name, after DESC by @age, after ASC by @id', async (t) => {
+  const arr = [
+    {id: 9, age: 26, name: 'pedro'},
+    {id: 6, age: 21, name: 'Pedro'},
+    {id: 7, age: 26, name: 'Maria'},
+    {id: 2, age: 26, name: 'maría'},
+  ];
+
+  const expected = [
+    {id: 2, age: 26, name: 'maría'},
+    {id: 7, age: 26, name: 'Maria'},
+    {id: 9, age: 26, name: 'pedro'},
+    {id: 6, age: 21, name: 'Pedro'},
+  ];
+
+  sortBy(arr, item => [item.name, -item.age, item.id]);
+  t.deepEqual(arr, expected);
+});

test/sorting-by-name-age-id.js

@@ -0,0 +1,21 @@
+import test from 'ava';
+import sortBy from '../dist/sort-by.min';
+
+test('Sorting DESC by @name', async (t) => {
+  const arr = [
+    {id: 4, name: 'Pedro'},
+    {id: 6, name: 'Lucía'},
+    {id: 7, name: 'paco'},
+    {id: 3, name: 'luis'},
+  ];
+
+  const expected = [
+    {id: 4, name: 'Pedro'},
+    {id: 7, name: 'paco'},
+    {id: 3, name: 'luis'},
+    {id: 6, name: 'Lucía'},
+  ];
+
+  sortBy(arr, item => `DESC:${item.name}`);
+  t.deepEqual(arr, expected);
+});

test/sorting-by-name.js

@@ -0,0 +1,10 @@
+import test from 'ava';
+import sortBy from '../dist/sort-by.min';
+
+test('Sorting DESC: date-strings as Date', async (t) => {
+  const arr = ['1983/03/06', '1980/12/24', '1985/08/31', '1983/03/05'];
+  const expected = ['1985/08/31', '1983/03/06', '1983/03/05', '1980/12/24'];
+
+  sortBy(arr, s => -new Date(s));
+  t.deepEqual(arr, expected);
+});

test/sorting-desc-date.js

@@ -1,7 +1,7 @@
 import test from 'ava';
 import sortBy from '../dist/sort-by.min';
 
-test('Sorting DESC', async (t) => {
+test('Sorting DESC: numbers', async (t) => {
   const arr = [5, 1, 8, 0, 3, 7, 10, 4, 3, 8];
   const expected = [10, 8, 8, 7, 5, 4, 3, 3, 1, 0];
 

test/sorting-desc.js renamed to test/sorting-desc-numbers.js

@@ -0,0 +1,16 @@
+import test from 'ava';
+import sortBy from '../dist/sort-by.min';
+
+/**
+ * Because we use the minus (-) symbol to specify a descending order,
+ * it would produce a `NaN` value if used with a `String` value.
+ * So the flag `"desc:"` (not case sensitive) is prefixed
+ * to the string value in the `parser` callback.
+ */
+test('Sorting DESC: strings', async (t) => {
+  const arr = ['único', 'cosas', 'Árbol', 'fútbol', 'algo'];
+  const expected = ['único', 'fútbol', 'cosas', 'Árbol', 'algo'];
+
+  sortBy(arr, item => `desc:${item}`);
+  t.deepEqual(arr, expected);
+});