Tests for drop, distance and differenceBy

test/differenceBy/differenceBy.test.js

@@ -5,9 +5,11 @@ test('Testing differenceBy', (t) => {
   //For more information on all the methods supported by tape
   //Please go to https://github.com/substack/tape
   t.true(typeof differenceBy === 'function', 'differenceBy is a Function');
+  t.deepEqual(differenceBy([2.1, 1.2], [2.3, 3.4], Math.floor), [1.2], 'Works using a native function and numbers');
+  t.deepEqual(differenceBy([{ x: 2 }, { x: 1 }], [{ x: 1 }], v => v.x), [ { x: 2 } ], 'Works with arrow function and objects');
   //t.deepEqual(differenceBy(args..), 'Expected');
   //t.equal(differenceBy(args..), 'Expected');
   //t.false(differenceBy(args..), 'Expected');
   //t.throws(differenceBy(args..), 'Expected');
   t.end();
-});
+});

test/distance/distance.test.js

@@ -5,9 +5,10 @@ test('Testing distance', (t) => {
   //For more information on all the methods supported by tape
   //Please go to https://github.com/substack/tape
   t.true(typeof distance === 'function', 'distance is a Function');
+  t.equals(distance(1, 1, 2, 3), 2.23606797749979, 'Calculates the distance between two points');
   //t.deepEqual(distance(args..), 'Expected');
   //t.equal(distance(args..), 'Expected');
   //t.false(distance(args..), 'Expected');
   //t.throws(distance(args..), 'Expected');
   t.end();
-});
+});

test/drop/drop.test.js

@@ -5,9 +5,12 @@ test('Testing drop', (t) => {
   //For more information on all the methods supported by tape
   //Please go to https://github.com/substack/tape
   t.true(typeof drop === 'function', 'drop is a Function');
+  t.deepEqual(drop([1, 2, 3]), [2,3], 'Works without the last argument');
+  t.deepEqual(drop([1, 2, 3], 2), [3], 'Removes appropriate element count as specified');
+  t.deepEqual(drop([1, 2, 3], 42), [], 'Empties array given a count greater than length');
   //t.deepEqual(drop(args..), 'Expected');
   //t.equal(drop(args..), 'Expected');
   //t.false(drop(args..), 'Expected');
   //t.throws(drop(args..), 'Expected');
   t.end();
-});
+});