feat(logic): Implement nand

Author: dawehner

src/index.d.ts

@@ -980,9 +980,10 @@ declare namespace RamdaAdjunct {
         neither(firstPredicate: Function, secondPredicate: Function): Function;
 
         /**
-         * Returns `true` if both arguments are falsy, otherwise `false`.
+         * Returns true if both arguments are falsy; false otherwise.
          */
         nand(a: any, b: any): Boolean;
+        nand(a: any): (b: any) => Boolean;
 
         /**
          * Takes a list of predicates and returns a predicate that returns true for a given list of

src/nand.js

@@ -1,7 +1,7 @@
 import { and, complement } from 'ramda';
 
 /**
- * Returns `true` if both arguments are falsy, otherwise `false`.
+ * Returns true if both arguments are falsy; false otherwise.
  *
  * @func nand
  * @memberOf RA
@@ -10,19 +10,18 @@ import { and, complement } from 'ramda';
  * @sig a -> b -> Boolean
  * @param {Boolean} a
  * @param {Boolean} b
- * @return {Boolean} True if both arguments are false.
+ * @return {Boolean} true if both arguments are false
  * @example
  *
- * RA.nand(True, True); //=> False
- * RA.nand(False, True); //=> True
- * RA.nand(True, False); //=> True
- * RA.nand(False, False); //=> True
- * RA.nand(1.0, 1.0); //=> False
- * RA.nand(1.0, 0); //=> True
- * RA.nand(0, 1.0); //=> True
- * RA.nand(0, 0); //=> True
+ * RA.nand(true, true); //=> false
+ * RA.nand(false, true); //=> true
+ * RA.nand(true, false); //=> true
+ * RA.nand(false, false); //=> true
+ * RA.nand(1.0, 1.0); //=> false
+ * RA.nand(1.0, 0); //=> true
+ * RA.nand(0, 1.0); //=> true
+ * RA.nand(0, 0); //=> true
  */
-
-const nand = complement(and);
+const nand = complement(and); // eslint-disable-line ramda/complement-simplification
 
 export default nand;

test/nand.js

@@ -1,16 +1,38 @@
-import * as R from 'ramda';
 import eq from './shared/eq';
-import { nand } from '../src';
+import * as RA from '../src';
 
-describe('nand', () => {
-  it('compared two values with nand', () => {
-    eq(nand(true, true), false);
-    eq(nand(false, true), true);
-    eq(nand(true, false), true);
-    eq(nand(false, false), true);
-    eq(nand(1.0, 1.0), false);
-    eq(nand(0.0, 1.0), true);
-    eq(nand(1.0, 0.0), true);
-    eq(nand(0.0, 0.0), true);
+describe('RA.nand', function() {
+  it('should work on booleans', function() {
+    eq(RA.nand(true, true), false);
+    eq(RA.nand(false, true), true);
+    eq(RA.nand(true, false), true);
+    eq(RA.nand(false, false), true);
   });
-});
+
+  it('should work on numbers', function() {
+    eq(RA.nand(1.0, 1.0), false);
+    eq(RA.nand(0.0, 1.0), true);
+    eq(RA.nand(1.0, 0.0), true);
+    eq(RA.nand(0.0, 0.0), true);
+  });
+
+  it('should work on a combination of things', function() {
+    eq(RA.nand(true, 1.0), false);
+    eq(RA.nand(null, true), true);
+    eq(RA.nand(1.0, undefined), true);
+    eq(RA.nand(0.0, false), true);
+    eq(RA.nand(null, null), true);
+    eq(RA.nand(null, undefined), true);
+  });
+
+  it('should support currying', function() {
+    eq(RA.nand(true, true), false);
+    eq(RA.nand(true)(true), false);
+    eq(RA.nand(false, true), true);
+    eq(RA.nand(false)(true), true);
+    eq(RA.nand(true, false), true);
+    eq(RA.nand(true)(false), true);
+    eq(RA.nand(false, false), true);
+    eq(RA.nand(false)(false), true);
+  });
+});