src/vs/workbench/services/extensionManagement/common/webExtensionsScannerService.ts/WebExtensionsScannerService/scanExtensionManifest
class WebExtensionsScannerService:	async scanExtensionManifest(extensionLocation: URI): Promise<IExtensionManifest | null> {
		const packageJSONUri = joinPath(extensionLocation, 'package.json');
		const context = await this.requestService.request({ type: 'GET', url: packageJSONUri.toString() }, CancellationToken.None);
		if (isSuccess(context)) {
			const content = await asText(context);
			if (content) {
				return JSON.parse(content);
			}
		}
		return null;
	}