From a25a49a2b8190ed683a9a496ab97984f3195edce Mon Sep 17 00:00:00 2001
From: Sergey Ufocoder <xufocoder@gmail.com>
Date: Fri, 18 Oct 2019 12:26:42 +0300
Subject: [PATCH 1/3] Extract `colors` util. Use `getRandomColor`

---
 src/reducers/subnetwork.js | 33 ++-------------------------------
 src/utils/colors.js        | 36 ++++++++++++++++++++++++++++++++++++
 src/utils/colors.test.js   | 16 ++++++++++++++++
 3 files changed, 54 insertions(+), 31 deletions(-)
 create mode 100644 src/utils/colors.js
 create mode 100644 src/utils/colors.test.js

diff --git a/src/reducers/subnetwork.js b/src/reducers/subnetwork.js
index abfd075..e0b51d6 100644
--- a/src/reducers/subnetwork.js
+++ b/src/reducers/subnetwork.js
@@ -5,36 +5,7 @@ import {
   REMOVE_SUPER_NODE,
 } from 'actions';
 
-const colorsBuilder = () => {
-  let list = [];
-  const allColors = ['#D84315', '#BF360C', '#FBC02D', '#F9A825', '#F57F17', '#FFA000', '#FF8F00', '#FF6F00', '#F57C00', '#EF6C00', '#E65100', '#388E3C', '#2E7D32', '#689F38', '#558B2F', '#AFB42B', '#0288D1', '#0097A7', '#00838F', '#1976D2', '#1565C0', '#C2185B'];
-  const shuffle = (array) => {
-    let currentIndex = array.length;
-    let temporaryValue;
-    let randomIndex;
-
-    while (currentIndex !== 0) {
-      randomIndex = Math.floor(Math.random() * currentIndex);
-      currentIndex -= 1;
-
-      temporaryValue = array[currentIndex];
-      array[currentIndex] = array[randomIndex];
-      array[randomIndex] = temporaryValue;
-    }
-
-    return array;
-  };
-
-  return () => {
-    if (list.length === 0) {
-      list = shuffle([...allColors]);
-    }
-
-    return list.shift();
-  };
-};
-
-const colorsNol = colorsBuilder();
+import { getRandomColor } from 'utils/colors';
 
 const formatNetwork = (state) => {
   const { network, positions, nodes } = state;
@@ -44,7 +15,7 @@ const formatNetwork = (state) => {
       ...network,
       nodes,
       positions,
-      color: colorsNol(),
+      color: getRandomColor(),
     };
   }
 
diff --git a/src/utils/colors.js b/src/utils/colors.js
new file mode 100644
index 0000000..c5680e3
--- /dev/null
+++ b/src/utils/colors.js
@@ -0,0 +1,36 @@
+export const COLORS = [
+  '#D84315',
+  '#BF360C',
+  '#FBC02D',
+  '#F9A825',
+  '#F57F17',
+  '#FFA000',
+  '#FF8F00',
+  '#FF6F00',
+  '#F57C00',
+  '#EF6C00',
+  '#E65100',
+  '#388E3C',
+  '#2E7D32',
+  '#689F38',
+  '#558B2F',
+  '#AFB42B',
+  '#0288D1',
+  '#0097A7',
+  '#00838F',
+  '#1976D2',
+  '#1565C0',
+  '#C2185B',
+];
+
+const shuffle = array => array.slice().sort(() => Math.random() - 0.5);
+
+export const getRandomColor = (() => {
+  let list = [];
+  return () => {
+    if (!list.length) {
+      list = shuffle(COLORS);
+    }
+    return list.shift();
+  };
+})();
diff --git a/src/utils/colors.test.js b/src/utils/colors.test.js
new file mode 100644
index 0000000..0787038
--- /dev/null
+++ b/src/utils/colors.test.js
@@ -0,0 +1,16 @@
+import { COLORS, getRandomColor } from './colors';
+
+describe('Colors Utils', () => {
+  describe('getRandomColor', () => {
+    it('returns truthy (keyCode)', () => {
+      const firstRandomColor = getRandomColor();
+      const secondRandomColor = getRandomColor();
+
+      if (COLORS.length === 1) {
+        expect(firstRandomColor).toBe(secondRandomColor);
+      } else {
+        expect(firstRandomColor).not.toBe(secondRandomColor);
+      }
+    });
+  });
+});

From 0c2639f0bc6f1ac1990569c8ae8dc4c8577e1cc2 Mon Sep 17 00:00:00 2001
From: Sergey Ufocoder <xufocoder@gmail.com>
Date: Sun, 20 Oct 2019 17:01:24 +0300
Subject: [PATCH 2/3] Refactor `src/utils/colors`

---
 src/utils/colors.js | 12 ++++++++----
 1 file changed, 8 insertions(+), 4 deletions(-)

diff --git a/src/utils/colors.js b/src/utils/colors.js
index c5680e3..eb6a35a 100644
--- a/src/utils/colors.js
+++ b/src/utils/colors.js
@@ -1,3 +1,5 @@
+import { sort, isEmpty } from 'ramda';
+
 export const COLORS = [
   '#D84315',
   '#BF360C',
@@ -23,14 +25,16 @@ export const COLORS = [
   '#C2185B',
 ];
 
-const shuffle = array => array.slice().sort(() => Math.random() - 0.5);
+const shuffle = sort(() => Math.random() - 0.5);
 
-export const getRandomColor = (() => {
+const createRandomColorBuilder = () => {
   let list = [];
   return () => {
-    if (!list.length) {
+    if (isEmpty(list)) {
       list = shuffle(COLORS);
     }
     return list.shift();
   };
-})();
+};
+
+export const getRandomColor = createRandomColorBuilder();

From f92f1d3e303248594b7f9709b6cd88aa8feeb32a Mon Sep 17 00:00:00 2001
From: Sergey Ufocoder <xufocoder@gmail.com>
Date: Sun, 20 Oct 2019 17:01:35 +0300
Subject: [PATCH 3/3] Improve test for `src/utils/colors` lib

---
 src/utils/colors.test.js | 27 +++++++++++++++++++--------
 1 file changed, 19 insertions(+), 8 deletions(-)

diff --git a/src/utils/colors.test.js b/src/utils/colors.test.js
index 0787038..3572d2c 100644
--- a/src/utils/colors.test.js
+++ b/src/utils/colors.test.js
@@ -1,16 +1,27 @@
+import { times } from 'ramda';
 import { COLORS, getRandomColor } from './colors';
 
 describe('Colors Utils', () => {
   describe('getRandomColor', () => {
-    it('returns truthy (keyCode)', () => {
-      const firstRandomColor = getRandomColor();
-      const secondRandomColor = getRandomColor();
+    beforeAll(() => {
+      jest.spyOn(Math, 'random').mockReturnValue(0.5);
+    });
+
+    afterAll(() => {
+      Math.random.mockRestore();
+    });
+
+    it('returns "#388E3C" on the first time', () => {
+      expect(getRandomColor()).toBe('#388E3C');
+    });
+
+    it('returns "#D84315" on the second time', () => {
+      expect(getRandomColor()).toBe('#D84315');
+    });
 
-      if (COLORS.length === 1) {
-        expect(firstRandomColor).toBe(secondRandomColor);
-      } else {
-        expect(firstRandomColor).not.toBe(secondRandomColor);
-      }
+    it('returns "#388E3C" on the twenty first time', () => {
+      times(getRandomColor, COLORS.length - 2);
+      expect(getRandomColor()).toBe('#388E3C');
     });
   });
 });