feat: implement none

src/all.js

@@ -39,6 +39,7 @@ module.exports = {
    * @param {function(?): boolean} pred Predicate
    * @param {Array|Object|string} xs List of values
    * @returns {boolean}
+   * @see none
    */
   all: curry((pred, xs) => {
     for (let [_, v] of iter(xs)) if (pred(v) !== true) return false;

src/none.js

@@ -0,0 +1,44 @@
+/**
+ * @license MIT
+ * @copyright (c) 2021 Julien Gonzalez <hello@spinjs.com>
+ */
+
+const iter = require('./_iterable');
+const {curry} = require('./curry');
+
+/**
+ * @namespace
+ * @alias ROOT
+ */
+module.exports = {
+  /**
+  * True if all elements of `xs` didn't satisfy predicate `pred`.
+  * Otherwise returns false as soon as one did.
+  *
+  * @example
+  * > Check that a list does not contain any 'x'
+  *
+  * ```javascript
+  * const no_x = none(x => x === 'x');
+  *
+  * no_x(['a','b','c']);            //=> true
+  * no_x(['a','x','c']);            //=> false
+  *
+  * no_x('abc');                    //=> true
+  * no_x('axc');                    //=> false
+  * 
+  * no_x({m: 'a', n: 'b', o: 'c'}); //=> true
+  * no_x({m: 'a', n: 'x', o: 'c'}); //=> false
+  * ```
+  *
+  * @public
+  * @param {function(?): boolean} pred Predicate
+  * @param {Array|Object|string} xs List of values
+  * @returns {boolean}
+  * @see all
+  */
+  none: curry((pred, xs) => {
+    for (let [_, v] of iter(xs)) if (pred(v) === true) return false;
+    return true;
+  })
+};

test/none.test.js

@@ -0,0 +1,66 @@
+const td = require('testdouble');
+const test = require('tape');
+const {none: sut} = require('..');
+
+test('none(pred)(xs) -> true when xs is empty', t => {
+  const f = td.func();
+  t.same(sut(f)([]), true);
+  t.same(sut(f)(""), true);
+  t.same(sut(f)({}), true);
+  td.verify(f(), {times: 0, ignoreExtraArgs: true});
+  t.end();
+});
+
+test('none(pred)(xs) -> true if pred(x) returned false for all x', t => {
+  const f = td.func();
+  const g = td.func();
+  const h = td.func();
+  td.when(f(1)).thenReturn(false);
+  td.when(f(2)).thenReturn(false);
+  td.when(g(4)).thenReturn(false);
+  td.when(g(5)).thenReturn(false);
+  td.when(h("🥑")).thenReturn(false);
+  td.when(h("🌯")).thenReturn(false);
+  t.same(sut(f)([1, 2]), true);
+  t.same(sut(g)({a: 4, b: 5}), true);
+  t.same(sut(h)("🥑🌯"), true);
+  td.verify(f(), {times: 2, ignoreExtraArgs: true});
+  td.verify(g(), {times: 2, ignoreExtraArgs: true});
+  td.verify(h(), {times: 2, ignoreExtraArgs: true});
+  t.end();
+});
+
+test('none(pred)(xs) -> false if pred(x) returned true (not truthy) for any x', t => {
+  const f = td.func();
+  const g = td.func();
+  const h = td.func();
+  td.when(f(1)).thenReturn(true);
+  td.when(g(4)).thenReturn(true);
+  td.when(h("🥑")).thenReturn(true);
+  t.same(sut(f)([1, 2]), false);
+  t.same(sut(g)({a: 4, b: 5}), false);
+  t.same(sut(h)("🥑🌯"), false);
+  td.verify(f(), {times: 1, ignoreExtraArgs: true});
+  td.verify(g(), {times: 1, ignoreExtraArgs: true});
+  td.verify(h(), {times: 1, ignoreExtraArgs: true});
+  t.end();
+});
+
+test('none(pred)(xs) -> true even if pred(x) returned truthy for all x', t => {
+  const f = td.func();
+  const g = td.func();
+  const h = td.func();
+  td.when(f(1)).thenReturn(1);
+  td.when(f(2)).thenReturn([]);
+  td.when(g(4)).thenReturn('true');
+  td.when(g(5)).thenReturn({});
+  td.when(h("🥑")).thenReturn(10);
+  td.when(h("🌯")).thenReturn(20);
+  t.same(sut(f)([1, 2]), true);
+  t.same(sut(g)({a: 4, b: 5}), true);
+  t.same(sut(h)("🥑🌯"), true);
+  td.verify(f(), {times: 2, ignoreExtraArgs: true});
+  td.verify(g(), {times: 2, ignoreExtraArgs: true});
+  td.verify(h(), {times: 2, ignoreExtraArgs: true});
+  t.end();
+});