chore(bundle-size-tools): drop unused/flawed legacy behaviors (#27242)

Co-authored-by: Claude Opus 4.7 (1M context) <noreply@anthropic.com>

Author: ChumpChief

build-tools/packages/build-cli/src/commands/generate/bundleSizeDiff.ts

@@ -8,7 +8,6 @@ import path from "node:path";
 import {
 	ADOSizeComparator,
 	type BundleComparison,
-	type BundleMetric,
 	bundlesContainNoChanges,
 	getAzureDevopsApi,
 } from "@fluidframework/bundle-size-tools";
@@ -33,10 +32,6 @@ const defaultLocalReportPath = "./artifacts/bundleAnalyzerJson";
 // artifact.
 const defaultOutputDir = "./artifacts/bundleSizeDiff";
 
-// Any single non-total metric that grows by more than this threshold is considered a
-// regression.
-const sizeRegressionThresholdBytes = 5120;
-
 // Output file names. Only one of these is present per run: `result.json` when the
 // comparison produced a meaningful result, or `error.json` when it did not. Consumers
 // use file existence as the success/failure discriminator without needing to parse JSON.
@@ -46,17 +41,14 @@ const errorFileName = "error.json";
 /**
  * Shape of the `result.json` file produced on a successful comparison, discriminated by
  * `kind`. On `"no-changes"`, the comparison ran and found no size deltas. On `"changes"`,
- * the comparison found size deltas; `comparison` holds the diff and `sizeRegressionDetected`
- * flags any non-total metric that grew past the threshold.
+ * the comparison found size deltas and `comparison` holds the diff. The producer is
+ * unopinionated about what constitutes a "regression" — consumers apply their own thresholds.
  */
 type BundleSizeDiffResult = {
 	prNumber: number;
 	baseCommit: string;
 	targetBranch: string;
-} & (
-	| { kind: "no-changes" }
-	| { kind: "changes"; sizeRegressionDetected: boolean; comparison: BundleComparison[] }
-);
+} & ({ kind: "no-changes" } | { kind: "changes"; comparison: BundleComparison[] });
 
 /**
  * Shape of the `error.json` file produced when the command could not produce a comparison
@@ -70,18 +62,6 @@ interface BundleSizeDiffError {
 	error: string;
 }
 
-/**
- * Compute whether any bundle shows a metric growing by more than the regression threshold.
- */
-function detectSizeRegression(comparison: BundleComparison[]): boolean {
-	return comparison.some((bundle: BundleComparison) =>
-		Object.values(bundle.commonBundleMetrics).some(
-			({ baseline, compare }: { baseline: BundleMetric; compare: BundleMetric }) =>
-				compare.parsedSize - baseline.parsedSize > sizeRegressionThresholdBytes,
-		),
-	);
-}
-
 export default class GenerateBundleSizeDiff extends BaseCommand<
 	typeof GenerateBundleSizeDiff
 > {
@@ -134,10 +114,8 @@ export default class GenerateBundleSizeDiff extends BaseCommand<
 			adoConnection,
 			localReportPath,
 			targetBranch,
-			undefined,
-			ADOSizeComparator.naiveFallbackCommitGenerator,
 		);
-		const comparisonResult = await sizeComparator.getSizeComparison(false);
+		const comparisonResult = await sizeComparator.getSizeComparison();
 
 		const resolvedOutputDir = path.resolve(process.cwd(), outputDir);
 		await mkdir(resolvedOutputDir, { recursive: true });
@@ -183,12 +161,7 @@ export default class GenerateBundleSizeDiff extends BaseCommand<
 		};
 		const result: BundleSizeDiffResult = bundlesContainNoChanges(comparison)
 			? { ...common, kind: "no-changes" }
-			: {
-					...common,
-					kind: "changes",
-					sizeRegressionDetected: detectSizeRegression(comparison),
-					comparison,
-				};
+			: { ...common, kind: "changes", comparison };
 
 		await writeFile(resultPath, JSON.stringify(result, undefined, 2));
 		this.info(`Wrote ${resultPath}`);

build-tools/packages/bundle-size-tools/api-report/bundle-size-tools.api.md

@@ -10,38 +10,15 @@ import type { Build } from 'azure-devops-node-api/interfaces/BuildInterfaces';
 import type { BundleAnalyzerPlugin } from 'webpack-bundle-analyzer';
 import type JSZip from 'jszip';
 import { WebApi } from 'azure-devops-node-api';
-import type Webpack from 'webpack';
 
 // @public (undocumented)
 export class ADOSizeComparator {
     constructor(
     adoConstants: IADOConstants,
     adoConnection: WebApi,
     localReportPath: string,
-    targetBranch: string,
-    adoBuildId: number | undefined,
-    getFallbackCommit?: ((startingCommit: string) => Generator<string>) | undefined);
-    getSizeComparison(tagWaiting: boolean): Promise<SizeComparison>;
-    static naiveFallbackCommitGenerator(startingCommit: string): Generator<string>;
-}
-
-// @public (undocumented)
-export interface BannedModule {
-    moduleName: string;
-    reason: string;
-}
-
-// @public
-export class BannedModulesPlugin {
-    constructor(options: BannedModulesPluginOptions);
-    // (undocumented)
-    apply(compiler: Webpack.Compiler): void;
-}
-
-// @public (undocumented)
-export interface BannedModulesPluginOptions {
-    // (undocumented)
-    bannedModules: BannedModule[];
+    targetBranch: string);
+    getSizeComparison(): Promise<SizeComparison>;
 }
 
 // @public
@@ -124,9 +101,6 @@ export interface GetBuildOptions {
 // @public
 export function getBuilds(adoConnection: WebApi, options: GetBuildOptions): Promise<Build[]>;
 
-// @public
-export function getBuildTagForCommit(commitHash: string): string;
-
 // @public
 export function getBundleSummariesFromAnalyzer(args: GetBundleSummariesFromAnalyzerArgs): Promise<BundleSummaries>;
 
@@ -138,9 +112,6 @@ export interface GetBundleSummariesFromAnalyzerArgs {
     getAnalyzerJson: (relativePath: string) => Promise<BundleAnalyzerPlugin.JsonReport>;
 }
 
-// @public (undocumented)
-export function getPriorCommit(baseCommit: string): string;
-
 // @public
 export function getZipObjectFromArtifact(adoConnection: WebApi, projectName: string, buildNumber: number, artifactName: string): Promise<JSZip>;
 
@@ -155,11 +126,7 @@ export interface IADOConstants {
     // (undocumented)
     orgUrl: string;
     // (undocumented)
-    prBuildDefinitionId?: number;
-    // (undocumented)
     projectName: string;
-    // (undocumented)
-    projectRepoGuid?: string;
 }
 
 // @public

build-tools/packages/bundle-size-tools/package.json

@@ -42,8 +42,7 @@
 	"dependencies": {
 		"azure-devops-node-api": "^11.2.0",
 		"jszip": "^3.10.1",
-		"typescript": "~5.4.5",
-		"webpack": "^5.103.0"
+		"typescript": "~5.4.5"
 	},
 	"devDependencies": {
 		"@biomejs/biome": "~2.4.5",