NativeScript/nativescript-core/module-name-resolver/index.ts

import { ModuleNameResolver as ModuleNameResolverDefinition } from "./";
import { screen, device } from "../platform";
import * as appCommonModule from "../application/application-common";
import {
	PlatformContext,
	findMatch,
	stripQualifiers,
} from "./qualifier-matcher";
import { registerModulesFromFileSystem } from "./non-bundle-workflow-compat";
import { Trace } from "../trace";

export type ModuleListProvider = () => string[];

export class ModuleNameResolver implements ModuleNameResolverDefinition {
	private _cache = {};

	constructor(
		private context: PlatformContext,
		private moduleListProvider: ModuleListProvider = global.getRegisteredModules
	) {}

	public resolveModuleName(path: string, ext: string): string {
		const key = path + ext;
		let result: string = this._cache[key];
		if (result === undefined) {
			result = this.resolveModuleNameImpl(path, ext);
			this._cache[key] = result;
		}

		if (Trace.isEnabled()) {
			Trace.write(
				`path: '${path}' with ext: '${ext}' resolved: '${result}'`,
				Trace.categories.ModuleNameResolver
			);
		}

		return result;
	}

	public clearCache(): void {
		this._cache = {};
	}

	private resolveModuleNameImpl(path: string, ext: string): string {
		let result: string = null;
		ext = ext ? "." + ext : "";

		// Compatibility path for non-webpack workflow
		// register modules from FS first
		if (!global.TNS_WEBPACK) {
			registerModulesFromFileSystem(path);
		}

		// This call will return a clean path without qualifiers
		path = stripQualifiers(path);

		let candidates = this.getCandidates(path, ext);
		result = findMatch(path, ext, candidates, this.context);

		return result;
	}

	private getCandidates(path: string, ext: string): Array<string> {
		const candidates = this.moduleListProvider().filter(
			(moduleName) =>
				moduleName.startsWith(path) &&
				(!ext || moduleName.endsWith(ext))
		);

		return candidates;
	}
}

let resolverInstance: ModuleNameResolver;

export function resolveModuleName(path: string, ext: string): string {
	if (global.__snapshot) {
		return resolveModuleSnapshot(path, ext);
	}

	if (!resolverInstance) {
		resolverInstance = new ModuleNameResolver({
			width: screen.mainScreen.widthDIPs,
			height: screen.mainScreen.heightDIPs,
			os: device.os,
			deviceType: device.deviceType,
		});
	}

	return resolverInstance.resolveModuleName(path, ext);
}

function resolveModuleSnapshot(path, ext) {
	Trace.write(
		`Resolving module in SNAPSHOT context - path: '${path}' with ext: '${ext}'`,
		Trace.categories.ModuleNameResolver
	);

	// Platform module when in snapshot. So resolve modules with default android phone.
	// NB: The only module name that should ever be resolved while in snapshot is app.css, because it is
	// applied explicitly in the snapshot by [NativeScriptSnapshotPlugin](https://github.com/NativeScript/nativescript-dev-webpack/blob/48b26f412fd70c19dc0b9c7763e08e9505a0ae11/plugins/NativeScriptSnapshotPlugin/index.js#L48-L56)
	return new ModuleNameResolver({
		width: 400,
		height: 800,
		os: "Android",
		deviceType: "Phone",
	}).resolveModuleName(path, ext);
}

export function clearCache() {
	if (resolverInstance) {
		resolverInstance.clearCache();
	}
}

export function _setResolver(resolver: ModuleNameResolver) {
	resolverInstance = resolver;
}

appCommonModule.on("livesync", (args) => clearCache());
appCommonModule.on("orientationChanged", (args) => {
	resolverInstance = undefined;
});