feat(every): Add every module

Author: sargalias

src/recursion-practice/every/every.js

@@ -0,0 +1,19 @@
+const every = ([n1, ...rest], predicate) => {
+  const n1Result = predicate(n1);
+
+  if (rest.length === 0) {
+    return n1Result;
+  }
+  return n1Result && every([...rest], predicate);
+};
+
+const everyPTC = ([n1, ...rest], predicate, resultSoFar = true) => {
+  const newResultSoFar = resultSoFar && predicate(n1);
+  if (rest.length === 0) {
+    return newResultSoFar;
+  }
+
+  return everyPTC([...rest], predicate, newResultSoFar);
+};
+
+export { every, everyPTC };

src/recursion-practice/every/every.test.js

@@ -0,0 +1,19 @@
+import each from 'jest-each';
+import { every, everyPTC } from './every';
+
+[every, everyPTC].forEach(fn => {
+  describe(`${fn.name}`, () => {
+    each`
+      arr           | predicate             | expected
+      ${[1, 2, 3]}  | ${el => el < 7}       | ${true}
+      ${[1, 2, 7]}  | ${el => el < 7}       | ${false}
+      ${[1, 2, 3]}  | ${el => el % 2 === 0} | ${false}
+      ${[2, 4, 6]}  | ${el => el % 2 === 0} | ${true}
+    `.test(
+      'should return $expected when called with $arr and $predicate',
+      ({ arr, predicate, expected }) => {
+        expect(fn(arr, predicate)).toBe(expected);
+      },
+    );
+  });
+});