From 4c4803745410d2d0eab4bbd59d22719d99f9cc7b Mon Sep 17 00:00:00 2001
From: Jonas Drieghe <jonasd@madewithlove.be>
Date: Tue, 13 Nov 2018 21:09:55 +0100
Subject: [PATCH 1/2] Add isMajorScale function

---
 src/isMajorScale/index.js | 27 +++++++++++++++++++++++++++
 src/isMajorScale/test.js  | 18 ++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 src/isMajorScale/index.js
 create mode 100644 src/isMajorScale/test.js

diff --git a/src/isMajorScale/index.js b/src/isMajorScale/index.js
new file mode 100644
index 0000000..cff2d50
--- /dev/null
+++ b/src/isMajorScale/index.js
@@ -0,0 +1,27 @@
+// @flow
+
+import isDiatonicScale from '../isDiatonicScale';
+import normalizeScale from '../normalizeScale';
+import getIntervals from '../getIntervals';
+import IONIAN from '../constants/Mode/IONIAN';
+
+type options = {
+  direction?: direction
+};
+
+const isMajorScale = (scale: Scale, { direction = 1 }: options = {}) => {
+  if (![-1, 1].includes(direction)) {
+    throw new Error('Direction should be 1 (up) or -1 (down)');
+  }
+
+  if (!isDiatonicScale(scale)) return false;
+
+  if (direction === -1) scale.reverse();
+
+  const normalizedScale = normalizeScale(scale);
+  const intervals = getIntervals(normalizedScale);
+
+  return IONIAN.join(',') === intervals.join(',');
+};
+
+export default isMajorScale;
diff --git a/src/isMajorScale/test.js b/src/isMajorScale/test.js
new file mode 100644
index 0000000..cdf6b0f
--- /dev/null
+++ b/src/isMajorScale/test.js
@@ -0,0 +1,18 @@
+// https://en.wikipedia.org/wiki/Major_scale
+
+import isMajorScale from './';
+
+describe('isMajorScale', () => {
+  it('should return true on major scale ', () => {
+    const scale = ['C', 'D', 'E', 'F', 'G', 'A', 'B'];
+    expect(isMajorScale(scale)).toBe(true);
+  });
+  it('should return true on major scale', () => {
+    const scale = ['C1', 'D1', 'E1', 'F1', 'G1', 'A1', 'B1'];
+    expect(isMajorScale(scale)).toBe(true);
+  });
+  it('should return false on minor scale ', () => {
+    const scale = ['A', 'B', 'C', 'D', 'E', 'F', 'G'];
+    expect(isMajorScale(scale)).toBe(false);
+  });
+});

From 21d5f262909dc76bd75ca5fac5ea4f72f964ab4c Mon Sep 17 00:00:00 2001
From: Jonas Drieghe <jonasd@madewithlove.be>
Date: Tue, 13 Nov 2018 21:17:49 +0100
Subject: [PATCH 2/2] Add isMinorScale

---
 src/isMinorScale/index.js | 27 +++++++++++++++++++++++++++
 src/isMinorScale/test.js  | 18 ++++++++++++++++++
 2 files changed, 45 insertions(+)
 create mode 100644 src/isMinorScale/index.js
 create mode 100644 src/isMinorScale/test.js

diff --git a/src/isMinorScale/index.js b/src/isMinorScale/index.js
new file mode 100644
index 0000000..2e8c45a
--- /dev/null
+++ b/src/isMinorScale/index.js
@@ -0,0 +1,27 @@
+// @flow
+
+import isDiatonicScale from '../isDiatonicScale';
+import normalizeScale from '../normalizeScale';
+import getIntervals from '../getIntervals';
+import AEOLIAN from '../constants/Mode/AEOLIAN';
+
+type options = {
+  direction?: direction
+};
+
+const isMinorScale = (scale: Scale, { direction = 1 }: options = {}) => {
+  if (![-1, 1].includes(direction)) {
+    throw new Error('Direction should be 1 (up) or -1 (down)');
+  }
+
+  if (!isDiatonicScale(scale)) return false;
+
+  if (direction === -1) scale.reverse();
+
+  const normalizedScale = normalizeScale(scale);
+  const intervals = getIntervals(normalizedScale);
+
+  return AEOLIAN.join(',') === intervals.join(',');
+};
+
+export default isMinorScale;
diff --git a/src/isMinorScale/test.js b/src/isMinorScale/test.js
new file mode 100644
index 0000000..1d87aa8
--- /dev/null
+++ b/src/isMinorScale/test.js
@@ -0,0 +1,18 @@
+// https://en.wikipedia.org/wiki/Minor_scale
+
+import isMinorScale from './';
+
+describe('isMinorScale', () => {
+  it('should return true on minor scale ', () => {
+    const scale = ['A', 'B', 'C', 'D', 'E', 'F', 'G'];
+    expect(isMinorScale(scale)).toBe(true);
+  });
+  it('should return true on minor scale', () => {
+    const scale = ['A1', 'B1', 'C2', 'D2', 'E2', 'F2', 'G2'];
+    expect(isMinorScale(scale)).toBe(true);
+  });
+  it('should return false on major scale ', () => {
+    const scale = ['C', 'D', 'E', 'F', 'G', 'A', 'B'];
+    expect(isMinorScale(scale)).toBe(false);
+  });
+});