Added tests

src/algorithms/statistics/linear-congruential-generator/__test__/lcg.test.js

@@ -0,0 +1,44 @@
+import lcg from '../lcg';
+
+describe('Linear Congruential Generator', () => {
+  it('should throw an error when a is less than 0', () => {
+    expect(() => {
+      lcg(-1, 0, 251, 3);
+    }).toThrow('a must be between 0 and m-1');
+  });
+
+  it('should throw an error when a is greater than or equal to m', () => {
+    expect(() => {
+      lcg(251, 0, 251, 3);
+    }).toThrow('a must be between 0 and m-1');
+  });
+
+  it('should throw an error when c is less than 0', () => {
+    expect(() => {
+      lcg(33, -1, 251, 3);
+    }).toThrow('c must be between 0 and m-1');
+  });
+  it('should throw an error when c is greater than or equal to m', () => {
+    expect(() => {
+      lcg(33, 251, 251, 3);
+    }).toThrow('c must be between 0 and m-1');
+  });
+  it('should throw an error when m is less than 2', () => {
+    expect(() => {
+      lcg(33, 0, 1, 3);
+    }).toThrow('m must be greater than 1');
+  });
+
+  it('should generate a sequence of random numbers between 0 and 1', () => {
+    const seed = 1234;
+    const a = 246049789;
+    const c = 0;
+    const m = 268435399;
+    let generatedNumbers = lcg(a, c, m, seed, 10);
+    generatedNumbers.forEach((number) => {
+      expect(number).toBeGreaterThanOrEqual(0);
+      expect(number).toBeLessThanOrEqual(1);
+    });
+    expect(new Set(generatedNumbers).size).toBe(generatedNumbers.length);
+  });
+});