GoogleChrome · paulirish · Jul 26, 2018 · Jul 25, 2018 · Jul 25, 2018 · Jul 25, 2018
diff --git a/jest.config.js b/jest.config.js
@@ -14,6 +14,7 @@ module.exports = {
     '!**/test/',
     '!**/scripts/',
   ],
+  setupTestFrameworkScriptFile: './lighthouse-core/test/test-utils.js',
   testEnvironment: 'node',
   testMatch: [
     '**/lighthouse-core/**/*-test.js',

diff --git a/lighthouse-core/test/audits/byte-efficiency/byte-efficiency-audit-test.js b/lighthouse-core/test/audits/byte-efficiency/byte-efficiency-audit-test.js
@@ -176,7 +176,7 @@ describe('Byte efficiency base audit', () => {
       ],
     }, graph, simulator);
 
-    assert.ok(result.displayValue);
+    expect(result.displayValue).toBeDisplayString(/savings of 2/);
   });
 
   it('should work on real graphs', async () => {

diff --git a/lighthouse-core/test/audits/byte-efficiency/uses-long-cache-ttl-test.js b/lighthouse-core/test/audits/byte-efficiency/uses-long-cache-ttl-test.js
@@ -46,7 +46,7 @@ describe('Cache headers audit', () => {
       assert.equal(items.length, 1);
       assert.equal(items[0].cacheLifetimeMs, 0);
       assert.equal(items[0].wastedBytes, 10000);
-      assert.ok(result.displayValue);
+      expect(result.displayValue).toBeDisplayString('1 resource found');
     });
   });
 
@@ -68,7 +68,7 @@ describe('Cache headers audit', () => {
       assert.equal(Math.round(items[1].wastedBytes), 8000);
       assert.equal(items[2].cacheLifetimeMs, 86400 * 1000);
       assert.equal(Math.round(items[2].wastedBytes), 4000);
-      assert.ok(result.displayValue);
+      expect(result.displayValue).toBeDisplayString('3 resources found');
     });
   });
 

diff --git a/lighthouse-core/test/audits/critical-request-chains-test.js b/lighthouse-core/test/audits/critical-request-chains-test.js
@@ -86,7 +86,7 @@ const mockArtifacts = (mockChain) => {
 describe('Performance: critical-request-chains audit', () => {
   it('calculates the correct chain result for failing example', () => {
     return CriticalRequestChains.audit(mockArtifacts(FAILING_REQUEST_CHAIN)).then(output => {
-      assert.ok(output.displayValue);
+      expect(output.displayValue).toBeDisplayString('2 chains found');
       assert.equal(output.rawValue, false);
       assert.ok(output.details);
     });

diff --git a/lighthouse-core/test/audits/dobetterweb/appcache-manifest-test.js b/lighthouse-core/test/audits/dobetterweb/appcache-manifest-test.js
@@ -16,7 +16,7 @@ describe('Appcache manifest audit', () => {
       AppCacheManifest: 'manifest-name',
     });
     assert.equal(auditResult.rawValue, false);
-    assert.ok(/manifest-name/.test(auditResult.displayValue));
+    expect(auditResult.displayValue).toBeDisplayString(/manifest-name/);
   });
 
   it('passes when <html> does not contain a manifest attribute', () => {

diff --git a/lighthouse-core/test/audits/dobetterweb/dom-size-test.js b/lighthouse-core/test/audits/dobetterweb/dom-size-test.js
@@ -25,7 +25,7 @@ describe('Num DOM nodes audit', () => {
     const auditResult = DOMSize.audit(artifact, {options});
     assert.equal(auditResult.score, 0.43);
     assert.equal(auditResult.rawValue, numNodes);
-    assert.ok(auditResult.displayValue);
+    expect(auditResult.displayValue).toBeDisplayString('1,500 nodes');
     assert.equal(auditResult.details.items[0].totalNodes, numNodes.toLocaleString());
     assert.equal(auditResult.details.items[0].depth, '1');
     assert.equal(auditResult.details.items[0].width, '2');

diff --git a/lighthouse-core/test/audits/metrics/estimated-input-latency-test.js b/lighthouse-core/test/audits/metrics/estimated-input-latency-test.js
@@ -29,7 +29,7 @@ describe('Performance: estimated-input-latency audit', () => {
     return Audit.audit(artifacts, {options, settings}).then(output => {
       assert.equal(Math.round(output.rawValue * 10) / 10, 17.1);
       assert.equal(output.score, 1);
-      assert.ok(output.displayValue);
+      expect(output.displayValue).toBeDisplayString('20\xa0ms');
     });
   });
 });
diff --git a/lighthouse-core/test/audits/metrics/first-meaningful-paint-test.js b/lighthouse-core/test/audits/metrics/first-meaningful-paint-test.js
@@ -27,7 +27,7 @@ describe('Performance: first-meaningful-paint audit', () => {
 
     assert.equal(fmpResult.score, 1);
     assert.equal(fmpResult.rawValue, 783.328);
-    assert.ok(fmpResult.displayValue);
+    expect(fmpResult.displayValue).toBeDisplayString('780\xa0ms');
   });
 
   it('computes FMP correctly for simulated', async () => {

diff --git a/lighthouse-core/test/audits/metrics/interactive-test.js b/lighthouse-core/test/audits/metrics/interactive-test.js
@@ -34,7 +34,7 @@ describe('Performance: interactive audit', () => {
     return Interactive.audit(artifacts, {options, settings}).then(output => {
       assert.equal(output.score, 1);
       assert.equal(Math.round(output.rawValue), 1582);
-      assert.ok(output.displayValue);
+      expect(output.displayValue).toBeDisplayString('1,580\xa0ms');
     });
   });
 
@@ -52,7 +52,7 @@ describe('Performance: interactive audit', () => {
     return Interactive.audit(artifacts, {options, settings}).then(output => {
       assert.equal(output.score, 0.97);
       assert.equal(Math.round(output.rawValue), 2712);
-      assert.ok(output.displayValue);
+      expect(output.displayValue).toBeDisplayString('2,710\xa0ms');
     });
   });
 });
diff --git a/lighthouse-core/test/audits/seo/robots-txt-test.js b/lighthouse-core/test/audits/seo/robots-txt-test.js
@@ -159,7 +159,7 @@ wrong
 
       assert.equal(auditResult.rawValue, false);
       assert.equal(auditResult.details.items.length, expectedErrors);
-      assert.ok(auditResult.displayValue);
+      expect(auditResult.displayValue).toBeDisplayString(/\d errors? found/);
     });
   });
 

diff --git a/lighthouse-core/test/audits/user-timing-test.js b/lighthouse-core/test/audits/user-timing-test.js
@@ -30,7 +30,7 @@ describe('Performance: user-timings audit', () => {
       assert.equal(blackListedUTs.length, 0, 'Blacklisted usertimings included in results');
 
       assert.equal(auditResult.rawValue, false);
-      assert.ok(auditResult.displayValue);
+      expect(auditResult.displayValue).toBeDisplayString('2 user timings');
 
       assert.equal(auditResult.details.items[0].name, 'measure_test');
       assert.equal(auditResult.details.items[0].timingType, 'Measure');

diff --git a/lighthouse-core/test/test-utils.js b/lighthouse-core/test/test-utils.js
@@ -0,0 +1,32 @@
+/**
+ * @license Copyright 2018 Google Inc. All Rights Reserved.
+ * 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.
+ */
+'use strict';
+
+/* eslint-env jest */
+
+const i18n = require('../lib/i18n');
+
+expect.extend({
+  toBeDisplayString(received, expected) {
+    const obj = {value: received};
+    i18n.replaceIcuMessageInstanceIds(obj, 'en-US');
+    const actual = obj.value;
+    const pass = expected instanceof RegExp ?
+      expected.test(actual) :
+      actual === expected;
+
+    const message = () =>
+      [
+        `${this.utils.matcherHint('.toBeDisplayString')}\n`,
+        `Expected object to be a display string matching:`,
+        `  ${this.utils.printExpected(expected)}`,
+        `Received:`,
+        `  ${this.utils.printReceived(actual)}`,
+      ].join('\n');
+
+    return {actual, message, pass};
+  },
+});