Method fetchModule

src/ModuleLoader.ts:404–456

(
		{ attributes, id, meta, moduleSideEffects, syntheticNamedExports }: ResolvedId,
		importer: string | undefined,
		isEntry: boolean,
		isPreload: PreloadType
	)

	// its dependencies to be loaded.
	// Otherwise, it returns immediately.
	private async fetchModule(
		{ attributes, id, meta, moduleSideEffects, syntheticNamedExports }: ResolvedId,
		importer: string | undefined,
		isEntry: boolean,
		isPreload: PreloadType
	): Promise<Module> {
		const existingModule = this.modulesById.get(id);
		if (existingModule instanceof Module) {
			if (importer && doAttributesDiffer(attributes, existingModule.info.attributes)) {
				this.options.onLog(
					LOGLEVEL_WARN,
					logInconsistentImportAttributes(existingModule.info.attributes, attributes, id, importer)
				);
			}
			await this.handleExistingModule(existingModule, isEntry, isPreload);
			return existingModule;
		}

		if (existingModule instanceof ExternalModule) {
			return error(logExternalModulesCannotBeTransformedToModules(existingModule.id));
		}

		const module = new Module(
			this.graph,
			id,
			this.options,
			isEntry,
			moduleSideEffects,
			syntheticNamedExports,
			meta,
			attributes
		);
		this.modulesById.set(id, module);
		const loadPromise: LoadModulePromise = this.addModuleSource(id, importer, module).then(() => [
			this.getResolveStaticDependencyPromises(module),
			this.getResolveDynamicImportPromises(module),
			loadAndResolveDependenciesPromise
		]);
		const loadAndResolveDependenciesPromise = waitForDependencyResolution(loadPromise).then(() =>
			this.pluginDriver.hookParallel('moduleParsed', [module.info])
		);
		loadAndResolveDependenciesPromise.catch(() => {
			/* avoid unhandled promise rejections */
		});
		this.moduleLoadPromises.set(module, loadPromise);
		const resolveDependencyPromises = await loadPromise;
		if (!isPreload) {
			await this.fetchModuleDependencies(module, ...resolveDependencyPromises);
		} else if (isPreload === RESOLVE_DEPENDENCIES) {
			await loadAndResolveDependenciesPromise;
		}
		return module;
	}

	private async fetchModuleDependencies(
		module: Module,