From d41c7c00ac0d139e8f6929c539b071d79b505ff7 Mon Sep 17 00:00:00 2001
From: Connor Clark <cjamcl@google.com>
Date: Mon, 10 Jun 2024 17:27:12 -0700
Subject: [PATCH] tests(lantern): remove Speedline from Lantern unit test for
 now (#16060)

---
 core/computed/metrics/lantern-speed-index.js      |  2 +-
 core/lib/lantern/metric.js                        |  2 +-
 core/lib/lantern/metrics/speed-index.js           |  4 ++--
 core/test/lib/lantern/metrics/speed-index-test.js | 11 ++++++-----
 4 files changed, 10 insertions(+), 9 deletions(-)

diff --git a/core/computed/metrics/lantern-speed-index.js b/core/computed/metrics/lantern-speed-index.js
index f2538e9b4298..afd2f1555413 100644
--- a/core/computed/metrics/lantern-speed-index.js
+++ b/core/computed/metrics/lantern-speed-index.js
@@ -34,7 +34,7 @@ class LanternSpeedIndex extends SpeedIndex {
     const speedline = await Speedline.request(data.trace, context);
     const fcpResult = await LanternFirstContentfulPaint.request(data, context);
     return this.computeMetricWithGraphs(data, context, {
-      speedline,
+      observedSpeedIndex: speedline.speedIndex,
       fcpResult,
     });
   }
diff --git a/core/lib/lantern/metric.js b/core/lib/lantern/metric.js
index f799c98e2d4b..9be8cd506f56 100644
--- a/core/lib/lantern/metric.js
+++ b/core/lib/lantern/metric.js
@@ -18,7 +18,7 @@ import {RESOURCE_TYPES} from '../../lib/network-request.js';
  * @property {LH.Artifacts.LanternMetric=} fcpResult
  * @property {LH.Artifacts.LanternMetric=} lcpResult
  * @property {LH.Artifacts.LanternMetric=} interactiveResult
- * @property {{speedIndex: number}=} speedline
+ * @property {number=} observedSpeedIndex
  */
 
 class Metric {
diff --git a/core/lib/lantern/metrics/speed-index.js b/core/lib/lantern/metrics/speed-index.js
index 6bf666a4e7d3..1154f32f9653 100644
--- a/core/lib/lantern/metrics/speed-index.js
+++ b/core/lib/lantern/metrics/speed-index.js
@@ -76,11 +76,11 @@ class SpeedIndex extends Metric {
    */
   static getEstimateFromSimulation(simulationResult, extras) {
     if (!extras.fcpResult) throw new Error('missing fcpResult');
-    if (!extras.speedline) throw new Error('missing speedline');
+    if (extras.observedSpeedIndex === undefined) throw new Error('missing observedSpeedIndex');
 
     const fcpTimeInMs = extras.fcpResult.pessimisticEstimate.timeInMs;
     const estimate = extras.optimistic
-      ? extras.speedline.speedIndex
+      ? extras.observedSpeedIndex
       : SpeedIndex.computeLayoutBasedSpeedIndex(simulationResult.nodeTimings, fcpTimeInMs);
     return {
       timeInMs: estimate,
diff --git a/core/test/lib/lantern/metrics/speed-index-test.js b/core/test/lib/lantern/metrics/speed-index-test.js
index ea2c98425e79..e48ac6b16f12 100644
--- a/core/test/lib/lantern/metrics/speed-index-test.js
+++ b/core/test/lib/lantern/metrics/speed-index-test.js
@@ -10,7 +10,6 @@ import {readJson} from '../../../test-utils.js';
 import {SpeedIndex} from '../../../../lib/lantern/metrics/speed-index.js';
 import {FirstContentfulPaint} from '../../../../lib/lantern/metrics/first-contentful-paint.js';
 import {getComputationDataFromFixture} from './metric-test-utils.js';
-import {Speedline} from '../../../../computed/speedline.js';
 
 const trace = readJson('../../../fixtures/artifacts/progressive-app/trace.json', import.meta);
 
@@ -18,11 +17,13 @@ const defaultThrottling = constants.throttling.mobileSlow4G;
 
 describe('Metrics: Lantern Speed Index', () => {
   it('should compute predicted value', async () => {
-    const context = {computedCache: new Map()};
     const data = await getComputationDataFromFixture({trace});
+    // TODO: observedSpeedIndex is from the Speedline library, and is used for optimistic
+    // mode. At the moment callers must pass the result into Lantern.
+    const observedSpeedIndex = 379.04474997520487;
     const result = await SpeedIndex.compute(data, {
       fcpResult: await FirstContentfulPaint.compute(data),
-      speedline: await Speedline.request(trace, context),
+      observedSpeedIndex,
     });
 
     expect({
@@ -40,11 +41,11 @@ Object {
 
   it('should compute predicted value for different settings', async () => {
     const settings = {throttlingMethod: 'simulate', throttling: {...defaultThrottling, rttMs: 300}};
-    const context = {computedCache: new Map()};
     const data = await getComputationDataFromFixture({trace, settings});
+    const observedSpeedIndex = 379.04474997520487;
     const result = await SpeedIndex.compute(data, {
       fcpResult: await FirstContentfulPaint.compute(data),
-      speedline: await Speedline.request(trace, context),
+      observedSpeedIndex,
     });
 
     expect({