Fix Dependency Review API response error handling

__tests__/dependency-graph.int.test.ts

@@ -0,0 +1,29 @@
+import {RequestError} from '@octokit/request-error'
+import * as dependencyGraph from '../src/dependency-graph'
+import * as core from '@actions/core'
+
+// mock call to core.getInput('repo-token'.. to avoid environment setup - Input required and not supplied: repo-token
+jest.mock('@actions/core', () => ({
+  getInput: (input: string) => {
+    if (input === 'repo-token') {
+      return 'gh_testtoken'
+    }
+  }
+}))
+
+test('it properly catches RequestError type', async () => {
+  const token = core.getInput('repo-token', {required: true})
+  expect(token).toBe('gh_testtoken')
+
+  //Integration test to make an API request using current dependencies and ensure response can parse into RequestError
+  try {
+    await dependencyGraph.compare({
+      owner: 'actions',
+      repo: 'dependency-review-action',
+      baseRef: 'refs/heads/master',
+      headRef: 'refs/heads/master'
+    })
+  } catch (error) {
+    expect(error).toBeInstanceOf(RequestError)
+  }
+})