feat(package-managers): resolve installed packages through the package manager

Add getInstalledPackagePath(packageName, fromDir) to the package manager
contract. The base implementation walks node_modules the way Node does;
a package manager with a different on-disk layout can override it.

Services whose call chains are already async now ask the package manager
where a package lives instead of resolving it themselves: plugins-service,
doctor short-import scan, versions-service, prepare-controller's runtime
package.json lookup, android-plugin-build-service's local gradle versions,
the preview command, test-init and PackageInstallationManager.

Sites reached only from synchronous code (getRuntimePackage in
project-data-service, the bundler executable lookup, the vitest and karma
readiness checks, the transitive walk in node-modules-dependencies-builder)
keep using the resolution helper directly.

Author: rigor789

PublicAPI.md

@@ -571,6 +571,26 @@ tns.npm.search(["nativescript", "cloud"]).then(output => {
 });
 ```
 
+### getInstalledPackagePath
+Locates a package the way the selected package manager laid it out on disk, so callers never have to assume a `node_modules` layout.
+
+* Definition:
+```TypeScript
+/**
+ * @param  {string} packageName The name of the package.
+ * @param  {string} fromDir     The directory whose dependencies are searched, usually the project directory.
+ * @return {Promise<string>} The absolute path of the package directory, or null when it is not installed.
+ */
+getInstalledPackagePath(packageName: string, fromDir: string): Promise<string>;
+```
+
+* Usage:
+```JavaScript
+tns.packageManager.getInstalledPackagePath("@nativescript/core", "/tmp/myProject").then(pathToPackage => {
+	console.log(pathToPackage ? `Installed at ${pathToPackage}` : "Not installed");
+});
+```
+
 ### view
 Provides information about a given package.
 

lib/commands/preview.ts

@@ -1,4 +1,3 @@
-import { resolvePackagePath } from "@rigor789/resolve-package-path";
 import * as path from "path";
 import { color } from "../color";
 import { IChildProcess } from "../common/declarations";
@@ -39,7 +38,7 @@ export class PreviewCommand extends Command({
 			await this.installLatestPreviewCLI();
 		}
 
-		const previewCLIPath = this.getPreviewCLIPath();
+		const previewCLIPath = await this.getPreviewCLIPath();
 
 		if (!previewCLIPath) {
 			await this.failMissingPreviewCLI();
@@ -60,10 +59,11 @@ export class PreviewCommand extends Command({
 		);
 	}
 
-	private getPreviewCLIPath(): string {
-		return resolvePackagePath(PREVIEW_CLI_PACKAGE, {
-			paths: [this.$projectData.projectDir],
-		});
+	private getPreviewCLIPath(): Promise<string> {
+		return this.$packageManager.getInstalledPackagePath(
+			PREVIEW_CLI_PACKAGE,
+			this.$projectData.projectDir,
+		);
 	}
 
 	private async failMissingPreviewCLI(): Promise<void> {

lib/commands/test-init.ts

@@ -2,7 +2,6 @@ import * as path from "path";
 import * as _ from "lodash";
 import { TESTING_FRAMEWORKS, ProjectTypes } from "../constants";
 import { fromWindowsRelativePathToUnix } from "../common/helpers";
-import { resolvePackageJSONPath } from "../helpers/package-path-helper";
 import { ITestInitializationService } from "../definitions/project";
 import { INodePackageManager } from "../declarations";
 import { IPluginsService } from "../definitions/plugins";
@@ -135,8 +134,12 @@ export class TestInitCommand extends Command({
 				path: this.options.path,
 			});
 
+			const modulePath = await this.$packageManager.getInstalledPackagePath(
+				mod.name,
+				projectDir,
+			);
 			const modulePackageJsonContent = this.$fs.readJson(
-				resolvePackageJSONPath(mod.name, { paths: [projectDir] }),
+				path.join(modulePath, "package.json"),
 			);
 			const modulePeerDependencies =
 				modulePackageJsonContent.peerDependencies || {};

lib/contracts/doctor-service.ts

@@ -34,5 +34,7 @@ export abstract class DoctorService {
 	}): Promise<boolean>;
 
 	/** Checks and notifies users of deprecated short imports in their app. */
-	abstract checkForDeprecatedShortImportsInAppDir(projectDir: string): void;
+	abstract checkForDeprecatedShortImportsInAppDir(
+		projectDir: string,
+	): Promise<void>;
 }

lib/contracts/package-manager.ts

@@ -99,6 +99,17 @@ export abstract class PackageManager {
 	 */
 	abstract getCachePath(): Promise<string>;
 
+	/**
+	 * Locates a package the way the package manager laid it out on disk.
+	 * @param  {string} packageName The name of the package.
+	 * @param  {string} fromDir     The directory whose dependencies are searched, usually the project directory.
+	 * @return {Promise<string>} The absolute path of the package directory, or null when it is not installed.
+	 */
+	abstract getInstalledPackagePath(
+		packageName: string,
+		fromDir: string,
+	): Promise<string>;
+
 	/**
 	 * Gets the name of the package manager used for the current process.
 	 * It can be read from the user settings or by passing -- option.

lib/controllers/prepare-controller.ts

@@ -25,7 +25,11 @@ import {
 	SupportedPlatform,
 	TrackActionNames,
 } from "../constants";
-import { IOptions, IWatchIgnoreListService } from "../declarations";
+import {
+	IOptions,
+	IWatchIgnoreListService,
+	IPackageManager,
+} from "../declarations";
 import {
 	INodeModulesDependenciesBuilder,
 	IPlatformController,
@@ -40,7 +44,6 @@ import {
 	IProjectDataService,
 	IProjectService,
 } from "../definitions/project";
-import { resolvePackageJSONPath } from "@rigor789/resolve-package-path";
 
 interface IPlatformWatcherData {
 	hasWebpackCompilerProcess: boolean;
@@ -82,6 +85,7 @@ export class PrepareController
 		private $markingModeService: IMarkingModeService,
 		private $projectConfigService: IProjectConfigService,
 		private $projectService: IProjectService,
+		private $packageManager: IPackageManager,
 	) {
 		super();
 	}
@@ -493,16 +497,15 @@ export class PrepareController
 				SCOPED_ANDROID_RUNTIME_NAME;
 		}
 		// try reading from installed runtime first before reading from the npm registry...
-		const installedRuntimePackageJSONPath = resolvePackageJSONPath(
-			runtimePackageName,
-			{
-				paths: [projectData.projectDir],
-			},
-		);
+		const installedRuntimePath =
+			await this.$packageManager.getInstalledPackagePath(
+				runtimePackageName,
+				projectData.projectDir,
+			);
 
-		if (installedRuntimePackageJSONPath) {
+		if (installedRuntimePath) {
 			installedRuntimePackageJSON = this.$fs.readJson(
-				installedRuntimePackageJSONPath,
+				path.join(installedRuntimePath, "package.json"),
 			);
 		}
 		const packageData: any = {

lib/declarations.d.ts

@@ -111,6 +111,17 @@ interface INodePackageManager {
 	 * @returns {string} The full path to npm cache directory
 	 */
 	getCachePath(): Promise<string>;
+
+	/**
+	 * Locates a package the way the package manager laid it out on disk.
+	 * @param  {string} packageName The name of the package.
+	 * @param  {string} fromDir     The directory whose dependencies are searched, usually the project directory.
+	 * @return {Promise<string>} The absolute path of the package directory, or null when it is not installed.
+	 */
+	getInstalledPackagePath(
+		packageName: string,
+		fromDir: string,
+	): Promise<string>;
 }
 
 /** @deprecated Kept so existing annotations compile; use the {@link PackageManager} contract. */

lib/package-managers/base-package-manager.ts

@@ -1,4 +1,5 @@
 import { isInteractive } from "../common/helpers";
+import { resolvePackagePath } from "../helpers/package-path-helper";
 import {
 	INodePackageManager,
 	IPackageInstallOptions,
@@ -144,6 +145,13 @@ export abstract class BasePackageManager implements INodePackageManager {
 		};
 	}
 
+	public async getInstalledPackagePath(
+		packageName: string,
+		fromDir: string,
+	): Promise<string> {
+		return resolvePackagePath(packageName, { paths: [fromDir] }) || null;
+	}
+
 	protected getInstallFlags(options: IPackageInstallOptions): string[] {
 		return this.mapFlags(options, this.installFlags);
 	}

lib/package-managers/index.ts

@@ -108,6 +108,15 @@ export class PackageManager implements IPackageManager {
 		return this.packageManager.getCachePath();
 	}
 
+	@exported("packageManager")
+	@invokeInit()
+	public getInstalledPackagePath(
+		packageName: string,
+		fromDir: string
+	): Promise<string> {
+		return this.packageManager.getInstalledPackagePath(packageName, fromDir);
+	}
+
 	public async getTagVersion(
 		packageName: string,
 		tag: string

lib/package-managers/package-installation-manager.ts

@@ -1,6 +1,5 @@
 import * as path from "path";
 import * as constants from "../constants";
-import { resolvePackagePath } from "../helpers/package-path-helper";
 import {
 	INpmInstallOptions,
 	INpmInstallResultInfo,
@@ -190,9 +189,10 @@ export class PackageInstallationManager implements IPackageInstallationManager {
 		projectDir: string
 	): Promise<string> {
 		// local installation takes precedence over cache
-		const inspectorPath = resolvePackagePath(inspectorNpmPackageName, {
-			paths: [projectDir],
-		});
+		const inspectorPath = await this.$packageManager.getInstalledPackagePath(
+			inspectorNpmPackageName,
+			projectDir
+		);
 		if (inspectorPath) {
 			return inspectorPath;
 		}
@@ -281,7 +281,10 @@ export class PackageInstallationManager implements IPackageInstallationManager {
 			version,
 			dev
 		);
-		return resolvePackagePath(installResultInfo.name, { paths: [pathToSave] });
+		return this.$packageManager.getInstalledPackagePath(
+			installResultInfo.name,
+			pathToSave
+		);
 	}
 
 	private async npmInstall(