test defaultTo

test/API.test.js

@@ -37,7 +37,6 @@ const args = [null, undefined, false, true, '', 'a', '0xFF', 5, String, /x/, x =
 
 with(R) {
 
-// defaultTo
 // head
 // is
 // last

test/defaultTo.test.js

@@ -0,0 +1,23 @@
+const
+    { defaultTo } = require('portable-fp'),
+    { testCurrying, varietyList } = require('./util'),
+    { expect } = require('chai');
+
+describe('defaultTo :: a → b → a | b', function() {
+    const
+        def = 'alternative',
+        applyDef = v => defaultTo(def, v),
+        defaults = [null, undefined, NaN],
+        nonDefaults = varietyList
+            .filter(x => x !== null && x !== undefined && x === x);
+
+    it('replaces null, undefined, and NaN with provided default', function() {
+        expect(nonDefaults.map(applyDef)).eql(nonDefaults);
+        expect(defaults.map(applyDef)).eql(defaults.map(x => def));
+    });
+
+    it('has arity of 2', () => expect(defaultTo).lengthOf(2));
+
+    it('is curried', testCurrying(defaultTo, [1, NaN], 1));
+
+});

test/init.test.js

@@ -39,7 +39,7 @@ describe('init :: [a] → [a]', function() {
     //  - expect(init(String)).eql('');
 
     it('returns empty array on (some) invalid defined input', function() {
-        const args = [true, false, {}, init, x => x, /x/];
+        const args = [NaN, true, false, {}, init, x => x, /x/];
         args.map(arg => expect(init(arg)).an('array').eql([]));
     });