Add test for helpers (#594)

Author: iRohitSingh

test/tests.js

@@ -1,4 +1,5 @@
 import('./tests/p5.Master.js');
+import('./tests/p5.Helpers.js');
 import('./tests/p5.Distortion.js');
 import('./tests/p5.Effect.js');
 import('./tests/p5.Filter.js');
@@ -10,6 +11,6 @@ import('./tests/p5.AudioVoice.js');
 import('./tests/p5.MonoSynth.js');
 import('./tests/p5.PolySynth.js');
 import('./tests/p5.SoundRecorder.js');
-import('./tests/p5.SoundFile.js')
-import('./tests/p5.Amplitude.js')
-import('./tests/p5.Oscillator.js')
+import('./tests/p5.SoundFile.js');
+import('./tests/p5.Amplitude.js');
+import('./tests/p5.Oscillator.js');

test/tests/p5.Helpers.js

@@ -0,0 +1,35 @@
+const expect = chai.expect;
+
+describe('Testing helpers function', function () {
+  it('p5.prototype.freqToMidi helper function', function () {
+    const midi = p5.prototype.freqToMidi(880);
+    expect(midi).to.equal(81);
+  });
+
+  it('p5.prototype.midiToFreq helper function', function () {
+    const freq = p5.prototype.midiToFreq(100);
+    expect(freq).to.equal(2637.0204553029594);
+  });
+
+  it('p5.prototype.noteToFreq helper function', function () {
+    const freq = p5.prototype.noteToFreq('C4');
+    expect(freq).to.equal(261.6255653005986);
+  });
+
+  it('p5.prototype.soundFormats helper function', function () {
+    // setting file format so that if we don't provide extension
+    // our file will be loaded because _checkFileFormats add it for us.
+
+    p5.prototype.soundFormats('mp3');
+    const file = p5.prototype._checkFileFormats('a');
+    expect(file).to.be.equal('a.mp3');
+
+    // if we don't provide a valid sound format then soundFormats wil throw
+    //error
+    try {
+      p5.prototype.soundFormats('ext');
+    } catch (err) {
+      expect(err).to.be.equal('ext is not a valid sound format!');
+    }
+  });
+});