import { Tree, UpdateRecorder } from '@angular-devkit/schematics';
import * as ts from 'typescript';
import { Path } from '@angular-devkit/core';
/**
 * Checks whether a specific import or provider exists in the specified metadata
 * array (`imports`, `providers`, etc.) of the `NgModule` decorator in the AppModule.
 *
 * This function locates the AppModule file of the given Angular project,
 * parses its AST, and inspects the specified metadata array to determine
 * if it includes an element matching the provided string (e.g., `CommonModule`, `HttpClientModule`).
 *
 * @param host - The virtual file system tree used by Angular schematics.
 * @param projectName - The name of the Angular project.
 * @param metadataFn - The name (string) to match against the elements of the metadata array.
 * @param metadataName - The metadata field to search in (e.g., 'imports', 'providers'). Defaults to 'imports'.
 * @returns A promise that resolves to `true` if the metadata function is found, or `false` otherwise.
 * @throws SchematicsException if the AppModule file or expected metadata is not found or malformed.
 */
export declare const hasImportInNgModule: (host: Tree, projectName: string, metadataFn: string, metadataName?: string) => Promise<boolean>;
/**
 * Attempts to locate the path of the `AppRoutingModule` file that is imported
 * within the root AppModule file of an Angular application.
 *
 * This function reads the AppModule file (resolved from the main file path),
 * parses its AST, and searches for an import declaration that imports
 * `AppRoutingModule`. Once found, it resolves the import path to a normalized
 * file path relative to the workspace root.
 *
 * @param tree - The virtual file system tree used by Angular schematics.
 * @param mainFilePath - The path to the main entry file of the Angular application (typically `main.ts`).
 * @returns A normalized workspace-relative path to the AppRoutingModule file if found, or `null` otherwise.
 * @throws If the route file path is resolved but the file does not exist in the tree.
 */
export declare function findAppRoutesModulePath(tree: Tree, mainFilePath: string): Promise<Path | null>;
/**
 * Cleans up empty or invalid expressions (e.g., extra commas) from the `imports` and `providers`
 * arrays in the NgModule decorator of an Angular module file.
 *
 * This function parses the source file's AST, locates the `NgModule` decorator, and processes
 * the `imports` and `providers` metadata fields. If these fields contain array literals with
 * empty slots (such as trailing or double commas), they are removed and the array is rewritten.
 *
 * @param source - The TypeScript source file containing the Angular module.
 * @param recorder - The recorder used to apply changes to the source file.
 */
export declare function cleanEmptyExprFromModule(source: ts.SourceFile, recorder: UpdateRecorder): void;