test: use assert.rejects and drop chai (#194)

package.json

@@ -55,15 +55,13 @@
     "@microsoft/api-extractor": "^7.8.10",
     "@octokit/types": "^6.12.2",
     "@types/async-retry": "^1.4.2",
-    "@types/chai": "^4.2.11",
     "@types/diff": "^5.0.0",
     "@types/mocha": "^8.0.0",
     "@types/node": "^14.0.20",
     "@types/pino": "^6.3.0",
     "@types/proxyquire": "^1.3.28",
     "@types/sinon": "^9.0.4",
     "c8": "^7.0.1",
-    "chai": "^4.2.0",
     "gts": "^3.0.0",
     "jsdoc": "^3.6.4",
     "jsdoc-fresh": "^1.0.1",

src/bin/code-suggester.ts

@@ -18,8 +18,6 @@ import * as yargs from 'yargs';
 import {CREATE_PR_COMMAND, REVIEW_PR_COMMAND, main} from './workflow';
 import {logger} from '../logger';
 
-// tslint:disable:no-unused-expression
-// yargs actually is a used expression. TS-lint does not detect it.
 yargs
   .scriptName('code-suggester')
   .usage('$0 <command> [args]')

system-test/main.test.ts

@@ -12,11 +12,11 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-import {assert} from 'chai';
+import * as assert from 'assert';
 import {describe, it} from 'mocha';
 
 describe('System test', () => {
   it('has a test case', () => {
-    assert.isOk(true);
+    assert.ok(true);
   });
 });

test/branch.ts

@@ -12,8 +12,10 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
+/* eslint-disable node/no-unsupported-features/node-builtins */
+
 import {describe, it, before, afterEach} from 'mocha';
-import {assert, expect} from 'chai';
+import * as assert from 'assert';
 import {octokit, setup} from './util';
 import * as sinon from 'sinon';
 import {GetResponseTypeFromEndpointMethod} from '@octokit/types';
@@ -65,7 +67,7 @@ describe('Branch', () => {
       .resolves(branchResponse);
     // // tests
     const headSHA = await getBranchHead(octokit, origin, 'master');
-    expect(headSHA).to.equal(branchResponse.data.commit.sha);
+    assert.strictEqual(headSHA, branchResponse.data.commit.sha);
     sandbox.assert.calledOnceWithExactly(getBranchStub, {
       owner: origin.owner,
       repo: origin.repo,
@@ -114,7 +116,7 @@ describe('Branch', () => {
       .resolves(createRefResponse);
     // tests
     const sha = await branch(octokit, origin, upstream, branchName, 'master');
-    expect(sha).to.equal(branchResponse.data.commit.sha);
+    assert.strictEqual(sha, branchResponse.data.commit.sha);
     sandbox.assert.calledOnceWithExactly(getBranchStub, {
       owner: upstream.owner,
       repo: upstream.repo,
@@ -166,7 +168,7 @@ describe('Branch', () => {
       'existing-branch',
       'master'
     );
-    expect(sha).to.equal(branchResponse.data.commit.sha);
+    assert.strictEqual(sha, branchResponse.data.commit.sha);
     sandbox.assert.calledOnceWithExactly(getBranchStub, {
       owner: upstream.owner,
       repo: upstream.repo,
@@ -181,13 +183,12 @@ describe('Branch', () => {
   });
 
   it('Branching fails when Octokit get branch fails', async () => {
-    sandbox.stub(octokit.repos, 'getBranch').rejects(Error(testErrorMessage));
-    try {
-      await branch(octokit, origin, upstream, branchName, 'master');
-      assert.fail();
-    } catch (err) {
-      expect(err.message).to.equal(testErrorMessage);
-    }
+    const error = new Error(testErrorMessage);
+    sandbox.stub(octokit.repos, 'getBranch').rejects(error);
+    await assert.rejects(
+      branch(octokit, origin, upstream, branchName, 'master'),
+      error
+    );
   });
   it('Branching fails when Octokit list branch fails', async () => {
     const branchResponseBody = await import(
@@ -199,14 +200,13 @@ describe('Branch', () => {
       url: 'http://fake-url.com',
       data: branchResponseBody,
     } as GetBranchResponse;
+    const error = new Error(testErrorMessage);
     sandbox.stub(octokit.repos, 'getBranch').resolves(branchResponse);
-    sandbox.stub(octokit.git, 'getRef').rejects(Error(testErrorMessage));
-    try {
-      await branch(octokit, origin, upstream, branchName, 'master');
-      assert.fail();
-    } catch (err) {
-      expect(err.message).to.equal(testErrorMessage);
-    }
+    sandbox.stub(octokit.git, 'getRef').rejects(error);
+    await assert.rejects(
+      branch(octokit, origin, upstream, branchName, 'master'),
+      error
+    );
   });
   it('Branching fails when Octokit create ref fails', async () => {
     const branchResponseBody = await import(
@@ -220,15 +220,14 @@ describe('Branch', () => {
     } as GetBranchResponse;
     sandbox.stub(octokit.repos, 'getBranch').resolves(branchResponse);
     const getRefError = Error('Not Found');
+    const createRefError = Error(testErrorMessage);
     Object.assign(getRefError, {status: 404});
     sandbox.stub(octokit.git, 'getRef').rejects(getRefError);
-    sandbox.stub(octokit.git, 'createRef').rejects(Error(testErrorMessage));
-    try {
-      await branch(octokit, origin, upstream, branchName, 'master');
-      assert.fail();
-    } catch (err) {
-      expect(err.message).to.equal(testErrorMessage);
-    }
+    sandbox.stub(octokit.git, 'createRef').rejects(createRefError);
+    await assert.rejects(
+      branch(octokit, origin, upstream, branchName, 'master'),
+      createRefError
+    );
   });
   it('Branching fails when primary branch specified did not match any of the branches returned', async () => {
     const branchResponseBody = await import(
@@ -241,16 +240,13 @@ describe('Branch', () => {
       data: branchResponseBody,
     } as GetBranchResponse;
     sandbox.stub(octokit.repos, 'getBranch').resolves(branchResponse);
-    try {
-      await branch(octokit, origin, upstream, branchName, 'non-master-branch');
-      assert.fail();
-    } catch (err) {
-      assert.isOk(true);
-    }
+    await assert.rejects(
+      branch(octokit, origin, upstream, branchName, 'non-master-branch')
+    );
   });
   it('the reference string parsing function correctly appends branch name to reference prefix', () => {
-    assert.equal(createRef('master'), 'refs/heads/master');
-    assert.equal(createRef('foo/bar/baz'), 'refs/heads/foo/bar/baz');
-    assert.equal(createRef('+++'), 'refs/heads/+++');
+    assert.strictEqual(createRef('master'), 'refs/heads/master');
+    assert.strictEqual(createRef('foo/bar/baz'), 'refs/heads/foo/bar/baz');
+    assert.strictEqual(createRef('+++'), 'refs/heads/+++');
   });
 });

test/cli.ts

@@ -1,5 +1,20 @@
+// Copyright 2020 Google LLC
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//      http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+/* eslint-disable node/no-unsupported-features/node-builtins */
 import {describe, it, afterEach} from 'mocha';
-import {assert, expect} from 'chai';
+import * as assert from 'assert';
 import {main, coerceUserCreatePullRequestOptions} from '../src/bin/workflow';
 import * as sinon from 'sinon';
 import * as proxyquire from 'proxyquire';
@@ -31,16 +46,12 @@ describe('main', () => {
       './handle-git-dir-change': stubHelperHandlers,
     });
     stubWorkFlow.main();
-    assert.isOk(true);
   });
   it('fails when there is no env variable', async () => {
-    try {
-      sandbox.stub(process.env, 'ACCESS_TOKEN').value(undefined);
-      await main();
-      assert.fail();
-    } catch (err) {
-      assert.isOk(true);
-    }
+    sandbox
+      .stub(process, 'env')
+      .value({...process.env, ACCESS_TOKEN: undefined});
+    await assert.rejects(main());
   });
 
   it('Fails when unrecognized command is given', async () => {
@@ -61,12 +72,7 @@ describe('main', () => {
     const stubWorkFlow = proxyquire.noCallThru()('../src/bin/workflow', {
       './handle-git-dir-change': stubHelperHandlers,
     });
-    try {
-      await stubWorkFlow.main();
-      assert.fail();
-    } catch (err) {
-      assert.isOk(true);
-    }
+    await assert.rejects(stubWorkFlow.main());
   });
 
   it('Passes up the error message when fetching change failed', async () => {
@@ -75,12 +81,7 @@ describe('main', () => {
       .stub(process, 'env')
       .value({...process.env, ACCESS_TOKEN: '123121312'});
     sandbox.stub(yargs, 'argv').value({...yargs.argv, _: ['unrecognized']});
-    try {
-      await main();
-      assert.fail();
-    } catch (err) {
-      assert.isOk(true);
-    }
+    await assert.rejects(main());
   });
 });
 
@@ -105,9 +106,7 @@ describe('Mapping pr yargs to create PR options', () => {
       fork: true,
       labels: ['automerge'],
     };
-
     sandbox.stub(yargs, 'argv').value({_: ['pr'], ...options});
-
-    expect(coerceUserCreatePullRequestOptions()).to.deep.equals(options);
+    assert.deepStrictEqual(coerceUserCreatePullRequestOptions(), options);
   });
 });