From ad3f39e3574a436f60b156d83149f94787ba45d2 Mon Sep 17 00:00:00 2001
From: Patrick Hulce <phulce@google.com>
Date: Wed, 28 Apr 2021 15:19:53 -0500
Subject: [PATCH] tests: add organic TTI savings case to byte efficieny audit
 (#12418)

---
 .../byte-efficiency-audit-test.js.snap        | 12 -----
 .../byte-efficiency-audit-test.js             | 51 +++++++++++++++----
 2 files changed, 40 insertions(+), 23 deletions(-)
 delete mode 100644 lighthouse-core/test/audits/byte-efficiency/__snapshots__/byte-efficiency-audit-test.js.snap

diff --git a/lighthouse-core/test/audits/byte-efficiency/__snapshots__/byte-efficiency-audit-test.js.snap b/lighthouse-core/test/audits/byte-efficiency/__snapshots__/byte-efficiency-audit-test.js.snap
deleted file mode 100644
index 53c04e346674..000000000000
--- a/lighthouse-core/test/audits/byte-efficiency/__snapshots__/byte-efficiency-audit-test.js.snap
+++ /dev/null
@@ -1,12 +0,0 @@
-// Jest Snapshot v1, https://goo.gl/fbAQLP
-
-exports[`Byte efficiency base audit should allow overriding of computeWasteWithTTIGraph 1`] = `
-Object {
-  "default": 560,
-  "justTTI": 504,
-}
-`;
-
-exports[`Byte efficiency base audit should create load simulator with the specified settings 1`] = `960`;
-
-exports[`Byte efficiency base audit should create load simulator with the specified settings 2`] = `21500`;
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
index 75e2b40904fa..fe6c9ed74447 100644
--- a/lighthouse-core/test/audits/byte-efficiency/byte-efficiency-audit-test.js
+++ b/lighthouse-core/test/audits/byte-efficiency/byte-efficiency-audit-test.js
@@ -15,6 +15,8 @@ const LoadSimulator = require('../../../computed/load-simulator.js');
 
 const trace = require('../../fixtures/traces/progressive-app-m60.json');
 const devtoolsLog = require('../../fixtures/traces/progressive-app-m60.devtools.log.json');
+const traceM78 = require('../../fixtures/traces/lcp-m78.json');
+const devtoolsLogM78 = require('../../fixtures/traces/lcp-m78.devtools.log.json');
 const assert = require('assert').strict;
 
 /* eslint-env jest */
@@ -230,16 +232,16 @@ describe('Byte efficiency base audit', () => {
     let result = await MockAudit.audit(artifacts, {settings, computedCache});
     // expect modest savings
     expect(result.numericValue).toBeLessThan(5000);
-    expect(result.numericValue).toMatchSnapshot();
+    expect(result.numericValue).toMatchInlineSnapshot(`960`);
 
     settings = {throttlingMethod: 'simulate', throttling: ultraSlowThrottling};
     result = await MockAudit.audit(artifacts, {settings, computedCache});
     // expect lots of savings
     expect(result.numericValue).not.toBeLessThan(5000);
-    expect(result.numericValue).toMatchSnapshot();
+    expect(result.numericValue).toMatchInlineSnapshot(`21500`);
   });
 
-  it('should allow overriding of computeWasteWithTTIGraph', async () => {
+  it('should compute TTI savings differently from load savings', async () => {
     class MockAudit extends ByteEfficiencyAudit {
       static audit_(artifacts, records) {
         return {
@@ -249,15 +251,44 @@ describe('Byte efficiency base audit', () => {
       }
     }
 
-    class MockJustTTIAudit extends MockAudit {
+    class MockTtiAudit extends MockAudit {
       static computeWasteWithTTIGraph(results, graph, simulator) {
-        // TODO: Pass in a graph that organically has a lower TTI result rather than forcing it
-        // to be scaled down.
-        return 0.9 * ByteEfficiencyAudit.computeWasteWithTTIGraph(results, graph, simulator,
+        return ByteEfficiencyAudit.computeWasteWithTTIGraph(results, graph, simulator,
           {includeLoad: false});
       }
     }
 
+    const artifacts = {
+      traces: {defaultPass: traceM78},
+      devtoolsLogs: {defaultPass: devtoolsLogM78},
+    };
+    const computedCache = new Map();
+
+    const modestThrottling = {rttMs: 150, throughputKbps: 1000, cpuSlowdownMultiplier: 2};
+    const settings = {throttlingMethod: 'simulate', throttling: modestThrottling};
+    const result = await MockAudit.audit(artifacts, {settings, computedCache});
+    const resultTti = await MockTtiAudit.audit(artifacts, {settings, computedCache});
+    expect(resultTti.numericValue).toBeLessThan(result.numericValue);
+    expect(result.numericValue).toMatchInlineSnapshot(`2120`);
+    expect(resultTti.numericValue).toMatchInlineSnapshot(`150`);
+  });
+
+  it('should allow overriding of computeWasteWithTTIGraph', async () => {
+    class MockAudit extends ByteEfficiencyAudit {
+      static audit_(artifacts, records) {
+        return {
+          items: records.map(record => ({url: record.url, wastedBytes: record.transferSize * 0.5})),
+          headings: [],
+        };
+      }
+    }
+
+    class MockOverrideAudit extends MockAudit {
+      static computeWasteWithTTIGraph(results, graph, simulator) {
+        return 0.5 * ByteEfficiencyAudit.computeWasteWithTTIGraph(results, graph, simulator);
+      }
+    }
+
     const artifacts = {
       traces: {defaultPass: trace},
       devtoolsLogs: {defaultPass: devtoolsLog},
@@ -267,9 +298,7 @@ describe('Byte efficiency base audit', () => {
     const modestThrottling = {rttMs: 150, throughputKbps: 1000, cpuSlowdownMultiplier: 2};
     const settings = {throttlingMethod: 'simulate', throttling: modestThrottling};
     const result = await MockAudit.audit(artifacts, {settings, computedCache});
-    const resultTti = await MockJustTTIAudit.audit(artifacts, {settings, computedCache});
-    // expect less savings with just TTI
-    expect(resultTti.numericValue).toBeLessThan(result.numericValue);
-    expect({default: result.numericValue, justTTI: resultTti.numericValue}).toMatchSnapshot();
+    const resultOverride = await MockOverrideAudit.audit(artifacts, {settings, computedCache});
+    expect(resultOverride.numericValue).toEqual(result.numericValue * 0.5);
   });
 });