From 83e2d3c4bd11dd0f70a4a6617ae473f43dd5519b Mon Sep 17 00:00:00 2001
From: Adam Raine <6752989+adamraine@users.noreply.github.com>
Date: Thu, 3 Feb 2022 10:30:30 -0500
Subject: [PATCH] tests(smoke): test array `_includes` and `lhr.timing`
 (#13619)

---
 lighthouse-cli/test/smokehouse/readme.md      |  4 +++
 .../test/smokehouse/report-assert.js          | 36 +++++++++++++++++++
 types/smokehouse.d.ts                         |  3 ++
 3 files changed, 43 insertions(+)

diff --git a/lighthouse-cli/test/smokehouse/readme.md b/lighthouse-cli/test/smokehouse/readme.md
index 72c7cdf2cf48..0a5875fe5c57 100644
--- a/lighthouse-cli/test/smokehouse/readme.md
+++ b/lighthouse-cli/test/smokehouse/readme.md
@@ -64,11 +64,15 @@ Individual elements of an array can be asserted by using numeric properties in a
 
 However, if an array literal is used as the expectation, an extra condition is enforced that the actual array _must_ have the same length as the provided expected array.
 
+Arrays can be checked against a subset of elements using the special `_includes` property. The value of `_includes` _must_ be an array. Each assertion in `_includes` will remove the matching item from consideration for the rest.
+
 **Examples**:
 | Actual | Expected | Result |
 | -- | -- | -- |
 | `[{url: 'http://badssl.com'}, {url: 'http://example.com'}]` | `{1: {url: 'http://example.com'}}` | ✅ PASS |
 | `[{timeInMs: 5}, {timeInMs: 15}]` | `{length: 2}` | ✅ PASS |
+| `[{timeInMs: 5}, {timeInMs: 15}]` | `{_includes: [{timeInMs: 5}]}` | ✅ PASS |
+| `[{timeInMs: 5}, {timeInMs: 15}]` | `{_includes: [{timeInMs: 5}, {timeInMs: 5}]}` | ❌ FAIL |
 | `[{timeInMs: 5}, {timeInMs: 15}]` | `[{timeInMs: 5}]` | ❌ FAIL |
 
 ### Special environment checks
diff --git a/lighthouse-cli/test/smokehouse/report-assert.js b/lighthouse-cli/test/smokehouse/report-assert.js
index d58b33563faa..88efaf129585 100644
--- a/lighthouse-cli/test/smokehouse/report-assert.js
+++ b/lighthouse-cli/test/smokehouse/report-assert.js
@@ -111,6 +111,35 @@ function findDifference(path, actual, expected) {
     const keyPath = path + keyAccessor;
     const expectedValue = expected[key];
 
+    if (key === '_includes') {
+      if (!Array.isArray(expectedValue)) throw new Error('Array subset must be array');
+      if (!Array.isArray(actual)) {
+        return {
+          path,
+          actual: 'Actual value is not an array',
+          expected,
+        };
+      }
+
+      const actualCopy = [...actual];
+      for (const expectedEntry of expectedValue) {
+        const matchingIndex =
+          actualCopy.findIndex(actualEntry => !findDifference(keyPath, actualEntry, expectedEntry));
+        if (matchingIndex !== -1) {
+          actualCopy.splice(matchingIndex, 1);
+          continue;
+        }
+
+        return {
+          path,
+          actual: 'Item not found in array',
+          expected: expectedEntry,
+        };
+      }
+
+      continue;
+    }
+
     const actualValue = actual[key];
     const subDifference = findDifference(keyPath, actualValue, expectedValue);
 
@@ -305,6 +334,12 @@ function collateResults(localConsole, actual, expected) {
     return makeComparison(auditName + ' audit', actualResult, expectedResult);
   });
 
+  const timingAssertions = [];
+  if (expected.lhr.timing) {
+    const comparison = makeComparison('timing', actual.lhr.timing, expected.lhr.timing);
+    timingAssertions.push(comparison);
+  }
+
   /** @type {Comparison[]} */
   const requestCountAssertion = [];
   if (expected.networkRequests) {
@@ -322,6 +357,7 @@ function collateResults(localConsole, actual, expected) {
     ...requestCountAssertion,
     ...artifactAssertions,
     ...auditAssertions,
+    ...timingAssertions,
   ];
 }
 
diff --git a/types/smokehouse.d.ts b/types/smokehouse.d.ts
index cd02ae67256f..b2bcc364a08f 100644
--- a/types/smokehouse.d.ts
+++ b/types/smokehouse.d.ts
@@ -20,6 +20,9 @@ declare global {
         code?: any;
         message?: any;
       };
+      timing?: {
+        entries?: any
+      }
     }
 
     export type ExpectedRunnerResult = {