feat(core): add finder method for barrel-less modules

Add a function that traverses through the tagged
directories and mark them as modules in the
barrel-less mode.

This is also supports tagging with placeholders
which are interpreted as simple wildcards.

packages/core/src/lib/config/default-config.ts

@@ -7,6 +7,7 @@ export const defaultConfig: SheriffConfig = {
   depRules: {},
   excludeRoot: false,
   enableBarrelLess: false,
+  encapsulatedFolderNameForBarrelLess: 'internal',
   log: false,
   entryFile: '',
   isConfigFileMissing: false,

packages/core/src/lib/config/sheriff-config.ts

@@ -3,5 +3,4 @@ import { UserSheriffConfig } from './user-sheriff-config';
 export type SheriffConfig = Required<UserSheriffConfig> & {
   // dependency rules will skip if `isConfigFileMissing` is true
   isConfigFileMissing: boolean;
-  barrelFileName: string;
 };

packages/core/src/lib/config/tests/parse-config.spec.ts

@@ -28,6 +28,7 @@ describe('parse Config', () => {
       'depRules',
       'excludeRoot',
       'enableBarrelLess',
+      "encapsulatedFolderNameForBarrelLess",
       'log',
       'entryFile',
       'isConfigFileMissing',
@@ -67,6 +68,7 @@ export const config: SheriffConfig = {
         tagging: {},
         depRules: { noTag: 'noTag' },
         enableBarrelLess: false,
+        encapsulatedFolderNameForBarrelLess: 'internal',
         excludeRoot: false,
         log: false,
         isConfigFileMissing: false,

packages/core/src/lib/config/user-sheriff-config.ts

@@ -112,10 +112,26 @@ export interface UserSheriffConfig {
   excludeRoot?: boolean;
 
   /**
-   * Enable the barrel-less mode. Set to false by default.
+   * The barrel file is usually the `index.ts` and exports
+   * those files which are available outside the module.
+   */
+  barrelFileName?: string;
+
+  /**
+   * The barrel-less approach means that the module
+   * does not have an `index.ts` file. Instead, all files
+   * are directly available, except those which are located
+   * in a special folder ("internal" be default).
    */
   enableBarrelLess?: boolean;
 
+  /**
+   * The encapsulated folder contains all files
+   * which are not available outside the module.
+   * By default, it is set to `internal`.
+   */
+  encapsulatedFolderNameForBarrelLess?: string;
+
   /**
    * enable internal logging and save it to `sheriff.log`
    */

packages/core/src/lib/fs/default-fs.spec.ts

@@ -109,4 +109,16 @@ describe('Default Fs', () => {
       ).toThrowError('cannot find a file that does not exist');
     });
   });
+
+  it('should only find directories', () => {
+    const subDirectories = fs.readDirectory(
+      toFsPath(path.join(__dirname, './find-nearest/test1/customers')),
+      'directory',
+    );
+    expect(subDirectories).toEqual(
+      [path.join(__dirname, './find-nearest/test1/customers/admin')].map(
+        toFsPath,
+      ),
+    );
+  });
 });

packages/core/src/lib/fs/default-fs.ts

@@ -16,6 +16,20 @@ export class DefaultFs extends Fs {
   readFile = (path: string): string =>
     fs.readFileSync(path, { encoding: 'utf-8' }).toString();
 
+  override readDirectory(
+    directory: FsPath,
+    filter?: 'none' | 'directory',
+  ): FsPath[] {
+    return fs
+      .readdirSync(directory)
+      .map((child) => toFsPath(path.join(directory, child)))
+      .filter((path) =>
+        filter === 'none'
+          ? true
+          : fs.lstatSync(path).isDirectory(),
+      )
+  }
+
   removeDir = (path: string) => {
     fs.rmSync(path, { recursive: true });
   };

packages/core/src/lib/fs/fs.ts

@@ -2,38 +2,42 @@ import * as path from 'path';
 import type { FsPath } from '../file-info/fs-path';
 
 export abstract class Fs {
-  abstract writeFile: (filename: string, contents: string) => void;
+  abstract writeFile(filename: string, contents: string): void;
   abstract appendFile(filename: string, contents: string): void;
-  abstract readFile: (path: FsPath) => string;
-  abstract removeDir: (path: FsPath) => void;
-  abstract createDir: (path: string) => void;
+  abstract readFile(path: FsPath): string;
+  abstract readDirectory(path: FsPath, filter?: 'none' | 'directory'): FsPath[];
+  abstract removeDir(path: FsPath): void;
+  abstract createDir(path: string): void;
   abstract exists(path: string): path is FsPath;
 
-  abstract tmpdir: () => string;
+  abstract tmpdir(): string;
 
   join = (...paths: string[]) => path.join(...paths);
 
-  abstract cwd: () => string;
+  abstract cwd(): string;
 
-  abstract findFiles: (path: FsPath, filename: string) => FsPath[];
+  abstract findFiles(path: FsPath, filename: string): FsPath[];
 
-  abstract print: () => void;
+  abstract print(): void;
 
   /**
    * Used for finding the nearest `tsconfig.json`. It traverses through the
    * parent folder and includes the directory of the referenceFile.
    * @param referenceFile
    * @param filename
    */
-  abstract findNearestParentFile: (
+  abstract findNearestParentFile(
     referenceFile: FsPath,
     filename: string,
-  ) => FsPath;
+  ): FsPath;
 
-  relativeTo = (from: string, to: string) => path.relative(from, to);
+  relativeTo(from: string, to: string) {
+    return path.relative(from, to);
+  }
 
-  getParent = (fileOrDirectory: FsPath): FsPath =>
-    path.dirname(fileOrDirectory) as FsPath;
+  getParent(fileOrDirectory: FsPath): FsPath {
+    return path.dirname(fileOrDirectory) as FsPath;
+  }
 
   pathSeparator = path.sep;
 

packages/core/src/lib/fs/getFs.ts

@@ -4,8 +4,15 @@ import { Fs } from './fs';
 
 let fsImplementation: 'default' | 'virtual' = 'default';
 
-export const useDefaultFs = () => (fsImplementation = 'default');
-export const useVirtualFs = () => (fsImplementation = 'virtual');
+export function useDefaultFs() {
+  fsImplementation = 'default';
+  return defaultFs
+}
+
+export function useVirtualFs() {
+  fsImplementation = 'virtual'
+  return virtualFs;
+}
 
 const getFs = (): Fs =>
   fsImplementation === 'default' ? defaultFs : virtualFs;

packages/core/src/lib/fs/virtual-fs.spec.ts

@@ -1,7 +1,7 @@
 import { beforeAll, beforeEach, describe, expect, it } from 'vitest';
 import { VirtualFs } from './virtual-fs';
 import { inVfs } from '../test/in-vfs';
-import { toFsPath } from '../file-info/fs-path';
+import { FsPath, toFsPath } from '../file-info/fs-path';
 import getFs, { useVirtualFs } from './getFs';
 import '../test/expect.extensions';
 import { EOL } from 'os';
@@ -262,4 +262,36 @@ describe('Virtual Fs', () => {
       expect(fs.relativeTo('/project', path)).toBe(solution);
     });
   }
+
+  describe('readDirectory', () => {
+    beforeEach(() => fs.reset());
+
+    it('should list files in directory', () => {
+      fs.writeFile('/project/index.ts', '');
+      fs.writeFile('/project/main.ts', '');
+      fs.writeFile('/project/sub/foobar.ts', '');
+      fs.writeFile('/project/foobar.ts', '');
+      const files = fs.readDirectory(toFsPath('/project'));
+
+      expect(files).toEqual(
+        ['index.ts', 'main.ts', 'sub', 'foobar.ts'].map((f) => `/project/${f}`),
+      );
+    });
+
+    it('should throw if directory does not exist', () => {
+      expect(() => fs.readDirectory('/projects' as FsPath)).toThrowError(
+        'directory /projects does not exist',
+      );
+    });
+
+    it('should only return directories', () => {
+      fs.writeFile('/project/index.ts', '');
+      fs.writeFile('/project/main.ts', '');
+      fs.writeFile('/project/sub/foobar.ts', '');
+      fs.writeFile('/project/foobar.ts', '');
+      const files = fs.readDirectory(toFsPath('/project'), 'directory');
+
+      expect(files).toEqual(['/project/sub']);
+    });
+  });
 });

packages/core/src/lib/fs/virtual-fs.ts

@@ -58,6 +58,20 @@ export class VirtualFs extends Fs {
     this.root.children.set('project', this.project);
   }
 
+  override readDirectory(
+    path: FsPath,
+    filter: 'none' | 'directory' = 'none',
+  ): FsPath[] {
+    const result = this.#getNode(path);
+    if (!result.exists) {
+      throw new Error(`directory ${path} does not exist`);
+    }
+
+    return Array.from(result.node.children.values())
+      .filter((node) => (filter === 'none' ? true : node.type === 'directory'))
+      .map((node) => this.#absolutePath(node));
+  }
+
   findFiles = (path: FsPath, filename: string): FsPath[] => {
     const result = this.#getNode(path);
     if (!result.exists) {
@@ -288,8 +302,8 @@ export class VirtualFs extends Fs {
   }
 
   override isFile(path: FsPath): boolean {
-    const node  = this.#getNodeOrThrow(path);
-    return node.node.type === 'file'
+    const node = this.#getNodeOrThrow(path);
+    return node.node.type === 'file';
   }
 }
 

packages/core/src/lib/main/parse-project.ts

@@ -40,9 +40,8 @@ export const parseProject = (
 
   const modulePaths = findModulePaths(
     projectDirs,
-    config.tagging,
-    config.barrelFileName,
-    config.enableBarrelLess,
+    rootDir,
+    config
   );
   const modules = createModules(
     unassignedFileInfo,

packages/core/src/lib/modules/find-module-paths.ts

@@ -1,19 +1,33 @@
 import { FsPath } from '../file-info/fs-path';
-import { findModulePathsWithoutBarrel } from "./internal/find-module-paths-without-barrel";
-import { TagConfig } from "../config/tag-config";
-import { findModulePathsWithBarrel } from "./internal/find-module-paths-with-barrel";
+import { findModulePathsWithBarrel } from './internal/find-module-paths-with-barrel';
+import { findModulePathsWithoutBarrel } from './internal/find-module-paths-without-barrel';
+import { SheriffConfig } from '../config/sheriff-config';
 
-export type ModulePathMap = Record<FsPath, boolean>
+export type ModulePathMap = Record<FsPath, boolean>;
 
 /**
  * Find module paths which can be defined via having a barrel file or the
  * configuration's property `modules`.
  *
  * If a module has a barrel file and an internal, it is of type barrel file.
  */
-export function findModulePaths(projectDirs: FsPath[], moduleConfig: TagConfig, barrelFileName: string, enableBarrelLess: boolean): ModulePathMap {
-  const modulesWithoutBarrel = enableBarrelLess ? findModulePathsWithoutBarrel(projectDirs, moduleConfig) : [];
-  const modulesWithBarrel = findModulePathsWithBarrel(projectDirs, barrelFileName);
+export function findModulePaths(
+  projectDirs: FsPath[],
+  rootDir: FsPath,
+  sheriffConfig: SheriffConfig,
+): ModulePathMap {
+  const {
+    tagging,
+    enableBarrelLess,
+    barrelFileName,
+  } = sheriffConfig;
+  const modulesWithoutBarrel = enableBarrelLess
+    ? findModulePathsWithoutBarrel(tagging, rootDir, barrelFileName)
+    : [];
+  const modulesWithBarrel = findModulePathsWithBarrel(
+    projectDirs,
+    barrelFileName,
+  );
   const modulePaths: ModulePathMap = {};
 
   for (const path of modulesWithoutBarrel) {

packages/core/src/lib/modules/internal/create-module-path-patterns-tree.ts

@@ -0,0 +1,58 @@
+export type ModulePathPatternsTree = {
+  [basePath: string]: ModulePathPatternsTree;
+};
+
+/**
+ * Create a tree structure from a list of module path patterns.
+ *
+ * Having a tree structure improves the performance because shared
+ * parent directories only have to be read once.
+ *
+ * For example, given the following patterns:
+ * ```typescript
+ * ['src/app/feat-*-module/*', 'src/app/services/*', 'src/app/shared/*']
+ * ```
+ *
+ * would end up in the following tree:
+ * ```typescript
+ * {
+ *   src: {
+ *     app: {
+ *       feat-*-module: {},
+ *       services: {},
+ *       shared: {}
+ *     }
+ *   }
+ * }
+ * ```
+ */
+export function createModulePathPatternsTree(
+  patterns: string[],
+): ModulePathPatternsTree {
+  const flatTree: Record<string, string[]> = {};
+
+  for (const pattern of patterns) {
+    const parts = pattern.split('/');
+    const basePath = parts[0]; // Get the top-level directory (e.g., "src")
+
+    const restOfPattern = parts.slice(1).join('/'); // Remove the top-level part
+
+    if (!flatTree[basePath]) {
+      flatTree[basePath] = [];
+    }
+
+    flatTree[basePath].push(restOfPattern || '');
+  }
+
+  // group next subdirectories
+  const tree: ModulePathPatternsTree = {};
+  for (const basePath in flatTree) {
+    const subPatterns = flatTree[basePath];
+    if (subPatterns.length === 1 && subPatterns[0] === '') {
+      tree[basePath] = {};
+    } else {
+      tree[basePath] = createModulePathPatternsTree(subPatterns);
+    }
+  }
+  return tree;
+}