test: Add test to check unexpected plugin return values

test/index.test.js

@@ -3,6 +3,7 @@ import proxyquire from 'proxyquire';
 import {stub} from 'sinon';
 import tempy from 'tempy';
 import SemanticReleaseError from '@semantic-release/error';
+import DEFINITIONS from '../lib/plugins/definitions';
 import {gitHead as getGitHead} from '../lib/git';
 import {gitRepo, gitCommits, gitTagVersion} from './helpers/git-utils';
 
@@ -261,4 +262,30 @@ test.serial('Throw SemanticReleaseError if repositoryUrl is not set and canot be
   // Verify error code and type
   t.is(error.code, 'ENOREPOURL');
   t.true(error instanceof SemanticReleaseError);
+
+test.serial('Throw an Error if returns an unexpected value', async t => {
+  // Create a git repository, set the current working directory at the root of the repo
+  await gitRepo();
+  // Add commits to the master branch
+  await gitCommits(['First']);
+  // Create the tag corresponding to version 1.0.0
+  await gitTagVersion('v1.0.0');
+  // Add new commits to the master branch
+  await gitCommits(['Second']);
+
+  const verifyConditions = stub().resolves();
+  const getLastRelease = stub().resolves('string');
+
+  const options = {
+    branch: 'master',
+    repositoryUrl: 'git@hostname.com:owner/module.git',
+    verifyConditions: [verifyConditions],
+    getLastRelease,
+  };
+
+  const error = await t.throws(t.context.semanticRelease(options), Error);
+
+  // Verify error message
+  t.regex(error.message, new RegExp(DEFINITIONS.getLastRelease.output.message));
+  t.regex(error.message, /Received: 'string'/);
 });