NativeScriptAngularCompilerPlugin.ts

import { parse, join } from "path";
import { AngularCompilerPlugin } from "@ngtools/webpack";

export function getAngularCompilerPlugin(platform: string): any {
    class NativeScriptAngularCompilerPlugin extends AngularCompilerPlugin {
        // This is the bridge between the @ngtols/webpack loader and the AngularCompilerPlugin plugin itself:
        // https://github.com/angular/angular-cli/blob/bf52b26219ffc16bed2dd55716e21773b415fd2a/packages/ngtools/webpack/src/loader.ts#L49
        // The problem is that the loader does not call the `hostReplacementPaths` method when asking for the compiledFile.
        // By overriding this method, we work around this issue and support platform specific files from the loader
        // that are not compiled by the AngularCompilerPlugin plugin. e.g. main.ts is the webpack entry point and
        // it's loaded by the @ngtools/webpack loader but its not compiled by the plugin because the TypeScript Compiler
        // knowns only about main.android.ts and main.ios.ts (main.ts is not imported/required anywhere in the app).
        getCompiledFile(file) {
            try {
                if (platform) {
                    const parsed = parse(file);
                    const platformFile = join(parsed.dir, `${parsed.name}.${platform}${parsed.ext}`);
                    const result = super.getCompiledFile(platformFile);
                    // In case there's some issue with the generation, getCompilePath may fail or
                    // produce a result with empty outputText and errorDependencies array populated with files.
                    if (result && result.outputText) {
                        return result;
                    }
                }
            }
            catch (e) { }

            return super.getCompiledFile(file);
        }
    }

    return NativeScriptAngularCompilerPlugin;
}