Created test and fixed implementation of web based generator.

Author: Johannestegner

.npmignore

@@ -4,4 +4,4 @@
 .eslintrc.json
 webpack.config.js
 .github
-tests
+test

src/WebGenerator.js

@@ -10,8 +10,8 @@ export default class WebGenerator extends Generator {
     }
 
     // Fallback to random if no crypto on window.
-    for (let i = 0; i < len; i++) {
-      list[i] = Math.random();
+    for (let i = len; i-- > 0;) {
+      list[i] = Math.floor(Math.random() * 256.0);
     }
 
     return list;

test/WebGenerator.test.js

@@ -0,0 +1,48 @@
+import WebGenerator from '../src/WebGenerator';
+
+const generator = new WebGenerator();
+
+describe('Tests for web generator.', () => {
+  test('Return value is correct type.', () => {
+    const result = generator.getRandom(10);
+    expect(result).toBeInstanceOf(Uint8Array);
+
+  });
+
+  test('List contains values between -255 and +255', () => {
+    const result = generator.getRandom(128);
+    let min = 0;
+    let max = 0;
+
+    result.forEach((obj) => {
+      if (obj < min) {
+        min = obj;
+      }
+      if (obj > max) {
+        max = obj;
+      }
+    });
+
+    expect(max).toBeLessThan(256);
+    expect(min).toBeGreaterThan(-256);
+  });
+
+  test('Two calls generates different values.', () => {
+    const one = generator.getRandom(20);
+    const two = generator.getRandom(20);
+
+    expect(JSON.stringify(one)).not.toStrictEqual(JSON.stringify(two));
+  });
+
+  test('Uses crypt of it exists.', () => {
+    window.crypto = {
+      getRandomValues (array) {
+        array = array.fill(1).values();
+      }
+    };
+    const result = generator.getRandom(10);
+    expect(result).toEqual(Uint8Array.from([1, 1, 1, 1, 1, 1, 1, 1, 1, 1]));
+
+  });
+});
+