perf - inline package.json and product.json (#219841)

build/lib/inlineMeta.ts

@@ -0,0 +1,56 @@
+/*---------------------------------------------------------------------------------------------
+ *  Copyright (c) Microsoft Corporation. All rights reserved.
+ *  Licensed under the MIT License. See License.txt in the project root for license information.
+ *--------------------------------------------------------------------------------------------*/
+
+import * as es from 'event-stream';
+import { basename } from 'path';
+import * as File from 'vinyl';
+
+export interface IInlineMetaContext {
+	readonly targetPaths: string[];
+	readonly packageJsonFn: () => string;
+	readonly productJsonFn: () => string;
+}
+
+const packageJsonMarkerId = 'BUILD_INSERT_PACKAGE_CONFIGURATION';
+const productJsonMarkerId = 'BUILD_INSERT_PRODUCT_CONFIGURATION';
+
+export function inlineMeta(result: NodeJS.ReadWriteStream, ctx: IInlineMetaContext): NodeJS.ReadWriteStream {
+	return result.pipe(es.through(function (file: File) {
+		if (matchesFile(file, ctx)) {
+			let content = file.contents.toString();
+			let markerFound = false;
+
+			const packageMarker = `${packageJsonMarkerId}:"${packageJsonMarkerId}"`; // this needs to be the format after esbuild has processed the file (e.g. double quotes)
+			if (content.includes(packageMarker)) {
+				content = content.replace(packageMarker, JSON.stringify(JSON.parse(ctx.packageJsonFn())).slice(1, -1) /* trim braces */);
+				markerFound = true;
+			}
+
+			const productMarker = `${productJsonMarkerId}:"${productJsonMarkerId}"`; // this needs to be the format after esbuild has processed the file (e.g. double quotes)
+			if (content.includes(productMarker)) {
+				content = content.replace(productMarker, JSON.stringify(JSON.parse(ctx.productJsonFn())).slice(1, -1) /* trim braces */);
+				markerFound = true;
+			}
+
+			if (markerFound) {
+				file.contents = Buffer.from(content);
+			} else if (content.includes(packageJsonMarkerId) || content.includes(productJsonMarkerId)) {
+				this.emit('error', new Error(`Unable to inline metadata because expected markers where not found in ${file.basename}.`));
+				return;
+			}
+		}
+
+		this.emit('data', file);
+	}));
+}
+
+function matchesFile(file: File, ctx: IInlineMetaContext): boolean {
+	for (const targetPath of ctx.targetPaths) {
+		if (file.basename === basename(targetPath)) { // TODO would be nicer to figure out root relative path to not match on false positives
+			return true;
+		}
+	}
+	return false;
+}