length check in match mock

package.json

@@ -9,7 +9,8 @@
   "contributors": [
     "Jack Cross <[email protected]>",
     "Nathan Force <[email protected]>",
-    "Jason Schapiro"
+    "Jason Schapiro",
+    "Jacob Franklin <[email protected]>"
   ],
   "scripts": {
     "postinstall": "lerna bootstrap",

packages/parrot-core/__tests__/utils/matchMock.spec.js

@@ -48,4 +48,18 @@ describe('matchMock', () => {
     const req = { path: '/squawk', headers: 'ahoy', 'Keep-Alive': 'timeout=5' };
     expect(matchMock(req, {}, mocks)).toEqual(mocks[0]);
   });
+
+  it('throws when mocks is not an array', () => {
+    const mocks = {};
+    expect(() => matchMock({}, {}, mocks)).toThrow(
+      'mocks is not an array as expected. What was passed: [object Object]'
+    );
+  });
+
+  it('throws when mocks is an empty array', () => {
+    const mocks = [];
+    expect(() => matchMock({}, {}, mocks)).toThrow(
+      'mocks is empty, and likely none are defined for the current scenario.'
+    );
+  });
 });

packages/parrot-core/src/utils/matchMock.js

@@ -35,6 +35,15 @@ function match(normalizedRequest) {
 
 export default function matchMock(normalizedRequest, platformRequest, mocks) {
   let matchedMock;
+
+  if (!Array.isArray(mocks)) {
+    throw new TypeError(`mocks is not an array as expected. What was passed: ${mocks}`);
+  }
+
+  if (mocks.length === 0) {
+    throw new TypeError('mocks is empty, and likely none are defined for the current scenario.');
+  }
+
   for (let index = 0; index < mocks.length; index += 1) {
     const mock = mocks[index];
     if (typeof mock === 'function') {