core(tsc): make CPUNode and NetworkNode a discriminated union (#5548)

lighthouse-core/audits/byte-efficiency/byte-efficiency-audit.js

@@ -7,11 +7,10 @@
 
 const Audit = require('../audit');
 const linearInterpolation = require('../../lib/statistics').linearInterpolation;
-const Interactive = require('../../gather/computed/metrics/lantern-interactive'); // eslint-disable-line max-len
-const Simulator = require('../../lib/dependency-graph/simulator/simulator'); // eslint-disable-line no-unused-vars
-const Node = require('../../lib/dependency-graph/node.js'); // eslint-disable-line no-unused-vars
+const Interactive = require('../../gather/computed/metrics/lantern-interactive');
 
-const NetworkNode = require('../../lib/dependency-graph/network-node.js'); // eslint-disable-line no-unused-vars
+/** @typedef {import('../../lib/dependency-graph/simulator/simulator')} Simulator */
+/** @typedef {import('../../lib/dependency-graph/base-node.js').Node} Node */
 
 const KB_IN_BYTES = 1024;
 
@@ -148,26 +147,24 @@ class UnusedBytes extends Audit {
     const originalTransferSizes = new Map();
     graph.traverse(node => {
       if (node.type !== 'network') return;
-      const networkNode = /** @type {NetworkNode} */ (node);
-      const result = resultsByUrl.get(networkNode.record.url);
+      const result = resultsByUrl.get(node.record.url);
       if (!result) return;
 
-      const original = networkNode.record.transferSize;
-      originalTransferSizes.set(networkNode.record.requestId, original);
+      const original = node.record.transferSize;
+      originalTransferSizes.set(node.record.requestId, original);
 
       const wastedBytes = result.wastedBytes;
-      networkNode.record.transferSize = Math.max(original - wastedBytes, 0);
+      node.record.transferSize = Math.max(original - wastedBytes, 0);
     });
 
     const simulationAfterChanges = simulator.simulate(graph, {label: afterLabel});
 
     // Restore the original transfer size after we've done our simulation
     graph.traverse(node => {
       if (node.type !== 'network') return;
-      const networkNode = /** @type {NetworkNode} */ (node);
-      const originalTransferSize = originalTransferSizes.get(networkNode.record.requestId);
+      const originalTransferSize = originalTransferSizes.get(node.record.requestId);
       if (originalTransferSize === undefined) return;
-      networkNode.record.transferSize = originalTransferSize;
+      node.record.transferSize = originalTransferSize;
     });
 
     const savingsOnOverallLoad = simulationBeforeChanges.timeInMs - simulationAfterChanges.timeInMs;

lighthouse-core/audits/byte-efficiency/render-blocking-resources.js

@@ -10,13 +10,14 @@
 'use strict';
 
 const Audit = require('../audit');
-const Node = require('../../lib/dependency-graph/node');
+const BaseNode = require('../../lib/dependency-graph/base-node');
 const ByteEfficiencyAudit = require('./byte-efficiency-audit');
 const UnusedCSS = require('./unused-css-rules');
 const WebInspector = require('../../lib/web-inspector');
 
-const Simulator = require('../../lib/dependency-graph/simulator/simulator'); // eslint-disable-line no-unused-vars
-const NetworkNode = require('../../lib/dependency-graph/network-node.js'); // eslint-disable-line no-unused-vars
+/** @typedef {import('../../lib/dependency-graph/simulator/simulator')} Simulator */
+/** @typedef {import('../../lib/dependency-graph/base-node.js').Node} Node */
+/** @typedef {import('../../lib/dependency-graph/network-node.js')} NetworkNode */
 
 // Because of the way we detect blocking stylesheets, asynchronously loaded
 // CSS with link[rel=preload] and an onload handler (see https://github.com/filamentgroup/loadCSS)
@@ -35,11 +36,10 @@ function getNodesAndTimingByUrl(nodeTimings) {
   const nodes = Array.from(nodeTimings.keys());
   nodes.forEach(node => {
     if (node.type !== 'network') return;
-    const networkNode = /** @type {NetworkNode} */ (node);
     const nodeTiming = nodeTimings.get(node);
     if (!nodeTiming) return;
 
-    urlMap[networkNode.record.url] = {node, nodeTiming};
+    urlMap[node.record.url] = {node, nodeTiming};
   });
 
   return urlMap;
@@ -149,16 +149,14 @@ class RenderBlockingResources extends Audit {
     const minimalFCPGraph = /** @type {NetworkNode} */ (fcpGraph.cloneWithRelationships(node => {
       // If a node can be deferred, exclude it from the new FCP graph
       const canDeferRequest = deferredIds.has(node.id);
-      if (node.type !== Node.TYPES.NETWORK) return !canDeferRequest;
-
-      const networkNode = /** @type {NetworkNode} */ (node);
+      if (node.type !== BaseNode.TYPES.NETWORK) return !canDeferRequest;
 
       const isStylesheet =
-        networkNode.record._resourceType === WebInspector.resourceTypes.Stylesheet;
+        node.record._resourceType === WebInspector.resourceTypes.Stylesheet;
       if (canDeferRequest && isStylesheet) {
         // We'll inline the used bytes of the stylesheet and assume the rest can be deferred
-        const wastedBytes = wastedCssBytesByUrl.get(networkNode.record.url) || 0;
-        totalChildNetworkBytes += (networkNode.record.transferSize || 0) - wastedBytes;
+        const wastedBytes = wastedCssBytesByUrl.get(node.record.url) || 0;
+        totalChildNetworkBytes += (node.record.transferSize || 0) - wastedBytes;
       }
       return !canDeferRequest;
     }));

lighthouse-core/gather/computed/metrics/lantern-estimated-input-latency.js

@@ -6,9 +6,11 @@
 'use strict';
 
 const LanternMetricArtifact = require('./lantern-metric');
-const Node = require('../../../lib/dependency-graph/node');
+const BaseNode = require('../../../lib/dependency-graph/base-node');
 const EstimatedInputLatency = require('./estimated-input-latency');
 
+/** @typedef {BaseNode.Node} Node */
+
 class LanternEstimatedInputLatency extends LanternMetricArtifact {
   get name() {
     return 'LanternEstimatedInputLatency';
@@ -82,7 +84,7 @@ class LanternEstimatedInputLatency extends LanternMetricArtifact {
     /** @type {Array<{start: number, end: number, duration: number}>} */
     const events = [];
     for (const [node, timing] of nodeTimings.entries()) {
-      if (node.type !== Node.TYPES.CPU) continue;
+      if (node.type !== BaseNode.TYPES.CPU) continue;
       if (timing.endTime < fmpTimeInMs) continue;
 
       events.push({

lighthouse-core/gather/computed/metrics/lantern-first-contentful-paint.js

@@ -6,9 +6,9 @@
 'use strict';
 
 const MetricArtifact = require('./lantern-metric');
-const Node = require('../../../lib/dependency-graph/node');
-const CPUNode = require('../../../lib/dependency-graph/cpu-node'); // eslint-disable-line no-unused-vars
-const NetworkNode = require('../../../lib/dependency-graph/network-node'); // eslint-disable-line no-unused-vars
+const BaseNode = require('../../../lib/dependency-graph/base-node');
+
+/** @typedef {BaseNode.Node} Node */
 
 class FirstContentfulPaint extends MetricArtifact {
   get name() {
@@ -42,13 +42,12 @@ class FirstContentfulPaint extends MetricArtifact {
     return dependencyGraph.cloneWithRelationships(node => {
       if (node.endTime > fcp && !node.isMainDocument()) return false;
       // Include EvaluateScript tasks for blocking scripts
-      if (node.type === Node.TYPES.CPU) {
-        return /** @type {CPUNode} */ (node).isEvaluateScriptFor(blockingScriptUrls);
+      if (node.type === BaseNode.TYPES.CPU) {
+        return node.isEvaluateScriptFor(blockingScriptUrls);
       }
 
-      const asNetworkNode = /** @type {NetworkNode} */ (node);
       // Include non-script-initiated network requests with a render-blocking priority
-      return asNetworkNode.hasRenderBlockingPriority() && asNetworkNode.initiatorType !== 'script';
+      return node.hasRenderBlockingPriority() && node.initiatorType !== 'script';
     });
   }
 
@@ -66,12 +65,12 @@ class FirstContentfulPaint extends MetricArtifact {
     return dependencyGraph.cloneWithRelationships(node => {
       if (node.endTime > fcp && !node.isMainDocument()) return false;
       // Include EvaluateScript tasks for blocking scripts
-      if (node.type === Node.TYPES.CPU) {
-        return /** @type {CPUNode} */ (node).isEvaluateScriptFor(blockingScriptUrls);
+      if (node.type === BaseNode.TYPES.CPU) {
+        return node.isEvaluateScriptFor(blockingScriptUrls);
       }
 
       // Include non-script-initiated network requests with a render-blocking priority
-      return /** @type {NetworkNode} */ (node).hasRenderBlockingPriority();
+      return node.hasRenderBlockingPriority();
     });
   }
 }

lighthouse-core/gather/computed/metrics/lantern-first-cpu-idle.js

@@ -5,10 +5,7 @@
  */
 'use strict';
 
-const Node = require('../../../lib/dependency-graph/node');
-const CPUNode = require('../../../lib/dependency-graph/cpu-node'); // eslint-disable-line no-unused-vars
-const NetworkNode = require('../../../lib/dependency-graph/network-node'); // eslint-disable-line no-unused-vars
-
+const BaseNode = require('../../../lib/dependency-graph/base-node');
 const FirstCPUIdle = require('./first-cpu-idle');
 const LanternInteractive = require('./lantern-interactive');
 
@@ -42,7 +39,7 @@ class LanternFirstCPUIdle extends LanternInteractive {
     /** @type {Array<{start: number, end: number}>} */
     const longTasks = [];
     for (const [node, timing] of nodeTimings.entries()) {
-      if (node.type !== Node.TYPES.CPU) continue;
+      if (node.type !== BaseNode.TYPES.CPU) continue;
       if (timing.duration < longTaskLength) continue;
       longTasks.push({start: timing.startTime, end: timing.endTime});
     }

lighthouse-core/gather/computed/metrics/lantern-first-meaningful-paint.js

@@ -6,9 +6,9 @@
 'use strict';
 
 const MetricArtifact = require('./lantern-metric');
-const Node = require('../../../lib/dependency-graph/node');
-const CPUNode = require('../../../lib/dependency-graph/cpu-node'); // eslint-disable-line no-unused-vars
-const NetworkNode = require('../../../lib/dependency-graph/network-node'); // eslint-disable-line no-unused-vars
+const BaseNode = require('../../../lib/dependency-graph/base-node');
+
+/** @typedef {BaseNode.Node} Node */
 
 class FirstMeaningfulPaint extends MetricArtifact {
   get name() {
@@ -42,13 +42,12 @@ class FirstMeaningfulPaint extends MetricArtifact {
     return dependencyGraph.cloneWithRelationships(node => {
       if (node.endTime > fmp && !node.isMainDocument()) return false;
       // Include EvaluateScript tasks for blocking scripts
-      if (node.type === Node.TYPES.CPU) {
-        return /** @type {CPUNode} */ (node).isEvaluateScriptFor(blockingScriptUrls);
+      if (node.type === BaseNode.TYPES.CPU) {
+        return node.isEvaluateScriptFor(blockingScriptUrls);
       }
 
-      const asNetworkNode = /** @type {NetworkNode} */ (node);
       // Include non-script-initiated network requests with a render-blocking priority
-      return asNetworkNode.hasRenderBlockingPriority() && asNetworkNode.initiatorType !== 'script';
+      return node.hasRenderBlockingPriority() && node.initiatorType !== 'script';
     });
   }
 
@@ -67,13 +66,12 @@ class FirstMeaningfulPaint extends MetricArtifact {
       if (node.endTime > fmp && !node.isMainDocument()) return false;
 
       // Include CPU tasks that performed a layout or were evaluations of required scripts
-      if (node.type === Node.TYPES.CPU) {
-        const asCpuNode = /** @type {CPUNode} */ (node);
-        return asCpuNode.didPerformLayout() || asCpuNode.isEvaluateScriptFor(requiredScriptUrls);
+      if (node.type === BaseNode.TYPES.CPU) {
+        return node.didPerformLayout() || node.isEvaluateScriptFor(requiredScriptUrls);
       }
 
       // Include all network requests that had render-blocking priority (even script-initiated)
-      return /** @type {NetworkNode} */ (node).hasRenderBlockingPriority();
+      return node.hasRenderBlockingPriority();
     });
   }
 

lighthouse-core/gather/computed/metrics/lantern-interactive.js

@@ -6,11 +6,11 @@
 'use strict';
 
 const MetricArtifact = require('./lantern-metric');
-const Node = require('../../../lib/dependency-graph/node');
-const CPUNode = require('../../../lib/dependency-graph/cpu-node'); // eslint-disable-line no-unused-vars
-const NetworkNode = require('../../../lib/dependency-graph/network-node'); // eslint-disable-line no-unused-vars
+const BaseNode = require('../../../lib/dependency-graph/base-node');
 const WebInspector = require('../../../lib/web-inspector');
 
+/** @typedef {BaseNode.Node} Node */
+
 // Any CPU task of 20 ms or more will end up being a critical long task on mobile
 const CRITICAL_LONG_TASK_THRESHOLD = 20;
 
@@ -40,19 +40,18 @@ class Interactive extends MetricArtifact {
 
     return dependencyGraph.cloneWithRelationships(node => {
       // Include everything that might be a long task
-      if (node.type === Node.TYPES.CPU) {
-        return /** @type {CPUNode} */ (node).event.dur > minimumCpuTaskDuration;
+      if (node.type === BaseNode.TYPES.CPU) {
+        return node.event.dur > minimumCpuTaskDuration;
       }
 
-      const asNetworkNode = /** @type {NetworkNode} */ (node);
       // Include all scripts and high priority requests, exclude all images
-      const isImage = asNetworkNode.record._resourceType === WebInspector.resourceTypes.Image;
-      const isScript = asNetworkNode.record._resourceType === WebInspector.resourceTypes.Script;
+      const isImage = node.record._resourceType === WebInspector.resourceTypes.Image;
+      const isScript = node.record._resourceType === WebInspector.resourceTypes.Script;
       return (
         !isImage &&
         (isScript ||
-          asNetworkNode.record.priority() === 'High' ||
-          asNetworkNode.record.priority() === 'VeryHigh')
+          node.record.priority() === 'High' ||
+          node.record.priority() === 'VeryHigh')
       );
     });
   }
@@ -101,7 +100,7 @@ class Interactive extends MetricArtifact {
     // @ts-ignore TS can't infer how the object invariants change
     return Array.from(nodeTimings.entries())
       .filter(([node, timing]) => {
-        if (node.type !== Node.TYPES.CPU) return false;
+        if (node.type !== BaseNode.TYPES.CPU) return false;
         return timing.duration > duration;
       })
       .map(([_, timing]) => timing.endTime)

lighthouse-core/gather/computed/metrics/lantern-metric.js

@@ -6,10 +6,12 @@
 'use strict';
 
 const ComputedArtifact = require('../computed-artifact');
-const Node = require('../../../lib/dependency-graph/node');
-const NetworkNode = require('../../../lib/dependency-graph/network-node'); // eslint-disable-line no-unused-vars
-const Simulator = require('../../../lib/dependency-graph/simulator/simulator'); // eslint-disable-line no-unused-vars
-const WebInspector = require('../../../lib/web-inspector');
+const BaseNode = require('../../../lib/dependency-graph/base-node');
+const ResourceType = require('../../../../third-party/devtools/ResourceType');
+
+/** @typedef {BaseNode.Node} Node */
+/** @typedef {import('../../../lib/dependency-graph/network-node')} NetworkNode */
+/** @typedef {import('../../../lib/dependency-graph/simulator/simulator')} Simulator */
 
 class LanternMetricArtifact extends ComputedArtifact {
   /**
@@ -18,14 +20,14 @@ class LanternMetricArtifact extends ComputedArtifact {
    * @return {Set<string>}
    */
   static getScriptUrls(dependencyGraph, condition) {
+    /** @type {Set<string>} */
     const scriptUrls = new Set();
 
     dependencyGraph.traverse(node => {
-      if (node.type === Node.TYPES.CPU) return;
-      const asNetworkNode = /** @type {NetworkNode} */ (node);
-      if (asNetworkNode.record._resourceType !== WebInspector.resourceTypes.Script) return;
-      if (condition && !condition(asNetworkNode)) return;
-      scriptUrls.add(asNetworkNode.record.url);
+      if (node.type === BaseNode.TYPES.CPU) return;
+      if (node.record._resourceType !== ResourceType.TYPES.Script) return;
+      if (condition && !condition(node)) return;
+      scriptUrls.add(node.record.url);
     });
 
     return scriptUrls;

lighthouse-core/gather/computed/metrics/lantern-speed-index.js

@@ -6,8 +6,9 @@
 'use strict';
 
 const MetricArtifact = require('./lantern-metric');
-const Node = require('../../../lib/dependency-graph/node');
-const CPUNode = require('../../../lib/dependency-graph/cpu-node'); // eslint-disable-line no-unused-vars
+const BaseNode = require('../../../lib/dependency-graph/base-node');
+
+/** @typedef {BaseNode.Node} Node */
 
 class SpeedIndex extends MetricArtifact {
   get name() {
@@ -95,10 +96,9 @@ class SpeedIndex extends MetricArtifact {
     /** @type {Array<{time: number, weight: number}>} */
     const layoutWeights = [];
     for (const [node, timing] of nodeTimings.entries()) {
-      if (node.type !== Node.TYPES.CPU) continue;
+      if (node.type !== BaseNode.TYPES.CPU) continue;
 
-      const cpuNode = /** @type {CPUNode} */ (node);
-      if (cpuNode.childEvents.some(x => x.name === 'Layout')) {
+      if (node.childEvents.some(x => x.name === 'Layout')) {
         const timingWeight = Math.max(Math.log2(timing.endTime - timing.startTime), 0);
         layoutWeights.push({time: timing.endTime, weight: timingWeight});
       }

lighthouse-core/gather/computed/page-dependency-graph.js

@@ -12,7 +12,7 @@ const NetworkAnalyzer = require('../../lib/dependency-graph/simulator/network-an
 const TracingProcessor = require('../../lib/traces/tracing-processor');
 const WebInspector = require('../../lib/web-inspector');
 
-const Node = require('../../lib/dependency-graph/node.js'); // eslint-disable-line no-unused-vars
+/** @typedef {import('../../lib/dependency-graph/base-node.js').Node} Node */
 
 // Tasks smaller than 10 ms have minimal impact on simulation
 const MINIMUM_TASK_DURATION_OF_INTEREST = 10;