jest-mock-random - npm Package Compare versions

Comparing version 1.0.0 to 1.0.1

__tests__/mockRandomWith.spec.js

@@ -25,2 +25,10 @@ const mockRandomWith = require('../index');
   });
+  describe('Corner case', () => {
+    mockRandomWith([]);
+    it('throw Error in case we pass an empty array', () => {
+      const actual = () => Math.random();
+
+      expect(actual).toThrow(TypeError);
+    });
+  });
   describe('Singular value', () => {
@@ -27,0 +35,0 @@ mockRandomWith(0.1);

index.js

@@ -6,5 +6,3 @@ // Warning in case the passed value is not a decimal
 const warnBrokenContract = (values) => {
-  if (!Array.isArray(values)) {
-    if (!isDecimal(values)) { showWarning(); }
-  } else if (!values.map(parseFloat).every(isDecimal)) {
+  if (!values.map(parseFloat).every(isDecimal)) {
     showWarning();
@@ -22,20 +20,20 @@ }
 const randomMock = (returnValues) => {
+  let arrayOfValues = returnValues;
   if (!Array.isArray(returnValues)) {
-    const number = parseFloat(returnValues);
-    return () => {
-      warnBrokenContract(number);
-      return number;
-    };
+    arrayOfValues = [returnValues];
   }
+
   let index = 0;
 
   return () => {
-    warnBrokenContract(returnValues);
-    if (index >= returnValues.length) {
+    if (arrayOfValues.length === 0) {
+      throw new TypeError('The value list must contain some value');
+    }
+    warnBrokenContract(arrayOfValues);
+    if (index >= arrayOfValues.length) {
       index = 0;
     }
-    return returnValues[index++];
+    return arrayOfValues[index++];
   };
 };
-
 // Through a copy of the global Math object we mock the random method
@@ -42,0 +40,0 @@ const createMathRandomMock = (values) => {

package.json

 {
   "name": "jest-mock-random",
-  "version": "1.0.0",
+  "version": "1.0.1",
   "description": "Math.random() as a deterministic jest mock function",
@@ -5,0 +5,0 @@ "main": "index.js",

README.md

 # jest-mock-random
-Math.random() as deterministic jest mock function
+
+`Math.random()` as deterministic [Jest mock function](https://facebook.github.io/jest/docs/mock-functions.html).
+
+## Install
+
+```bash
+~ npm install --save-dev jest-mock-random
+// or
+~ yarn add --dev jest-mock-random
+```
+
+## Usage
+
+jest-mock-random is used as an additional beforeEach for your sequence of test.
+
+```javascript
+import mockRandomWith from 'jest-mock-random';
+
+describe('Test with random usage', () => {
+  mockRandomWith([0.1, 0.2, 0.3, 0.6]);
+  it('assigns random the values that we want to mock in order', () => {
+    const actual = [Math.random(), Math.random(), Math.random(), Math.random()]; // [0.1, 0.2, 0.3, 0.6]
+
+    expect(actual).toEqual([0.1, 0.2, 0.3, 0.6]);
+  });
+});
+```
+mockRandomWith accept a single value that it will give back every time Math.random is called or an array of values that the mock will use as a circular array.
+
+The values could be or a decimal number or a string that represents a decimal.
+
+WARNING: if a no decimal value is passed it will print some warnings during the test.
+
+```javascript
+  mockRandomWith([0.1, 0.2]); // OK
+  mockRandomWith([0.1, '0.2']); // OK
+  mockRandomWith(['0.2', '0.2']); // OK
+  mockRandomWith(0.2); // OK
+  mockRandomWith('0.2'); // OK
+
+  mockRandomWith('a'); // WARNING
+  mockRandomWith(13); // WARNING
+  mockRandomWith({}); // WARNING
+  mockRandomWith([]); // WARNING
+  mockRandomWith(['a', 1]); // WARNING

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Improved metrics

Total package byte prevSize

135563

increased by1.18%

Lines of code

139

increased by3.73%

Number of lines in readme file

47

increased by1466.67%

No dependency changes