test: add test cases for util functions.

Author: ghosind

test/dynamicBuffer.spec.ts

@@ -2,7 +2,7 @@ import assert from 'assert';
 import { constants } from 'buffer';
 import { describe, it } from 'mocha';
 
-import { DynamicBuffer, isDynamicBuffer } from '../src';
+import { DynamicBuffer } from '../src';
 
 describe('Initialization tests', () => {
   it('Test initializing with default size', () => {
@@ -130,10 +130,3 @@ describe('Subarray test', () => {
     assert.equal(buf.toString(), '');
   });
 });
-
-describe('Tools methods test', () => {
-  it('Test isDynamicBuffer util method', () => {
-    assert.equal(isDynamicBuffer(Buffer.from('')), false);
-    assert.equal(isDynamicBuffer(new DynamicBuffer()), true);
-  });
-});

test/util.spec.ts

@@ -0,0 +1,42 @@
+import assert from 'assert';
+import { describe, it } from 'mocha';
+
+import { DynamicBuffer } from '../src';
+import { isDynamicBuffer, rangeCheck, swap } from '../src/utils';
+
+describe('Method isDynamicBuffer test', () => {
+  it('Test isDynamicBuffer util method', () => {
+    assert.equal(isDynamicBuffer(Buffer.from('')), false);
+    assert.equal(isDynamicBuffer(new DynamicBuffer()), true);
+  });
+});
+
+describe('Method rangeCheck test', () => {
+  it('Test rangeCheck', () => {
+    assert.doesNotThrow(() => {
+      rangeCheck('noLimit', 0);
+    });
+
+    assert.doesNotThrow(() => {
+      rangeCheck('valid', 0, 0, 5);
+    });
+
+    assert.throws(() => {
+      rangeCheck('less', 0, 5);
+    });
+
+    assert.throws(() => {
+      rangeCheck('greater', 10, 0, 5);
+    });
+  });
+});
+
+describe('Method swap test', () => {
+  it('Test swap', () => {
+    const buf = Buffer.alloc(2);
+    buf.write('ab');
+    swap(buf, 0, 1);
+    assert.equal(buf[0], 98);
+    assert.equal(buf[1], 97);
+  });
+});