add test for validating signature

src/client/validateSignature.js

@@ -19,8 +19,6 @@ export default class ValidateSignature {
         if (!expected || expected !== computed) {
             throw new Error('Invalid signature');
         }
-        else {
-            log.debug('Valid signature!');
-        }
+        log.debug('Valid signature!');
     }
 }

test/client/validateSignature.test.js

@@ -0,0 +1,54 @@
+import test from 'tape';
+import sinon from 'sinon';
+import crypto from 'crypto';
+import ValidateSignature from '../../src/client/validateSignature';
+
+test('ValidateSignature.constructor', (expect) => {
+    const validateSignature = new ValidateSignature('APP_SECRET');
+    expect.same(validateSignature, {
+        appSecret: 'APP_SECRET',
+    }, 'should contain the same structure');
+    expect.end();
+});
+
+test('ValidateSignature.validate - invalid signature', (expect) => {
+    sinon.stub(crypto, 'createHmac')
+        .returns({
+            update: (buffer, encoding) => ({
+                buffer: buffer,
+                encoding: encoding,
+            }),
+            digest: () => 'INVALID_SECRET',
+        });
+    const validateSignature = new ValidateSignature('APP_SECRET');
+    try {
+        validateSignature.validate({ get: () => 'INVALID_SECRET' }, {}, 'buffer');
+        expect.fail('should not throw error');
+    }
+    catch (err) {
+        expect.same(err.message, 'Invalid signature', 'should throw error');
+    }
+    expect.end();
+    crypto.createHmac.restore();
+});
+
+test('ValidateSignature.validate - valid signature', (expect) => {
+    sinon.stub(crypto, 'createHmac')
+        .returns({
+            update: (buffer, encoding) => ({
+                buffer: buffer,
+                encoding: encoding,
+            }),
+            digest: () => 'APP_SECRET',
+        });
+    const validateSignature = new ValidateSignature('APP_SECRET');
+    try {
+        validateSignature.validate({ get: () => 'APP_SECRET' }, {}, 'buffer');
+        expect.pass('should not throw error');
+    }
+    catch (err) {
+        expect.pass('should not throw error');
+    }
+    expect.end();
+    crypto.createHmac.restore();
+});