diff --git a/.gitignore b/.gitignore
index 52543cefe..abb084932 100644
--- a/.gitignore
+++ b/.gitignore
@@ -1,5 +1,6 @@
 **/coverage
 **/dist
+**/.tmp
 
 # We use tsconfig.base.json, tsconfig.json is generated by vite and may accidentally be left behind sometimes
 apps/**/tsconfig.json
diff --git a/apps/app-builder/src/__tests__/constants.ts b/apps/app-builder/src/__tests__/constants.ts
new file mode 100644
index 000000000..e9a4303a1
--- /dev/null
+++ b/apps/app-builder/src/__tests__/constants.ts
@@ -0,0 +1,5 @@
+import path from 'path';
+
+const dirname = new URL('.', import.meta.url).pathname;
+
+export const MOCK_ROOT_DIR = path.resolve(dirname, '../..', '.tmp');
diff --git a/apps/app-builder/src/__tests__/createTestContext.ts b/apps/app-builder/src/__tests__/createTestContext.ts
index 6de49bdbf..7de392127 100644
--- a/apps/app-builder/src/__tests__/createTestContext.ts
+++ b/apps/app-builder/src/__tests__/createTestContext.ts
@@ -1,31 +1,36 @@
 import {Command} from 'commander';
+import {type RecursivePartial} from '@myparcel/ts-utils';
 import {createDebugger, mergeDefaultConfig} from '../utils';
-import {type PdkBuilderContext, PdkPlatformName} from '../types';
+import {type CommandArgs, type PdkBuilderContext, PdkPlatformName} from '../types';
+import {MOCK_ROOT_DIR} from './constants';
 
-export const createTestContext = (context?: Partial<PdkBuilderContext>): PdkBuilderContext => {
-  const verbose = 0;
+type Input = RecursivePartial<PdkBuilderContext>;
+
+export const createTestContext = (context?: Input): PdkBuilderContext => {
+  const args = {
+    arguments: [],
+    command: new Command(),
+    dryRun: false,
+    parallel: false,
+    quiet: true,
+    verbose: 0,
+    version: '1.0.0',
+    ...context?.args,
+  } as CommandArgs;
 
   return {
-    args: {
-      arguments: [],
-      command: new Command(),
-      dryRun: false,
-      parallel: false,
-      quiet: true,
-      verbose,
-      version: '1.0.0',
-      ...context?.args,
-    },
+    args,
     config: mergeDefaultConfig({
       name: 'test',
       platforms: [PdkPlatformName.MyParcelNl, PdkPlatformName.MyParcelBe, PdkPlatformName.Flespakket],
       source: [],
+      // @ts-expect-error todo
       versionSource: [],
       ...context?.config,
     }),
-    debug: createDebugger('test', {verbose}),
+    debug: createDebugger('test', args),
     env: {
-      cwd: 'CWD',
+      cwd: MOCK_ROOT_DIR,
       config: {},
       configFiles: {},
       modulePackage: {},
@@ -38,5 +43,5 @@ export const createTestContext = (context?: Partial<PdkBuilderContext>): PdkBuil
       ...context?.env,
     },
     ...context,
-  };
+  } as PdkBuilderContext;
 };
diff --git a/apps/app-builder/src/__tests__/mockFileSystem.ts b/apps/app-builder/src/__tests__/mockFileSystem.ts
new file mode 100644
index 000000000..a07fb6e06
--- /dev/null
+++ b/apps/app-builder/src/__tests__/mockFileSystem.ts
@@ -0,0 +1,56 @@
+import path from 'path';
+import fs from 'fs';
+import {vi} from 'vitest';
+import {isObject, merge} from 'lodash-unified';
+import {createDirectory} from '../utils';
+import {MOCK_ROOT_DIR} from './constants';
+
+type Directories = Record<string, unknown>;
+
+const recursiveCreate = async (entries: Record<string, unknown>, rootDir = MOCK_ROOT_DIR): Promise<unknown[]> => {
+  return Promise.all(
+    Object.entries(entries).map(async ([filePath, contents]) => {
+      const fullPath = path.resolve(rootDir, filePath);
+      const directory = path.dirname(fullPath);
+
+      await createDirectory(directory, {recursive: true});
+
+      if (isObject(contents)) {
+        return recursiveCreate(contents as Record<string, unknown>, fullPath);
+      }
+
+      if (typeof contents === 'string') {
+        await fs.promises.writeFile(fullPath, contents);
+      }
+    }),
+  );
+};
+
+export const mockFileSystem = async (fileSystem?: Directories): Promise<void> => {
+  const base = {
+    config: {
+      'pdk.php': '<?php return [];',
+    },
+    src: {
+      Pdk: {
+        'MyParcelNLController.php': '<?php echo "Hello from MyParcelNL";',
+      },
+      'index.php': '<?php echo "Version: 1.0.0";',
+    },
+    'composer.json': JSON.stringify({
+      name: 'myparcelnl/app',
+      version: '1.0.0',
+    }),
+    'package.json': JSON.stringify({
+      name: '@myparcel/app',
+      version: '1.0.0',
+    }),
+    'readme.txt': 'Hello world!',
+  };
+
+  await recursiveCreate(merge({}, base, fileSystem));
+
+  vi.restoreAllMocks();
+};
+
+export const restoreFileSystem = async (): Promise<void> => {};
diff --git a/apps/app-builder/src/__tests__/spies/fs.ts b/apps/app-builder/src/__tests__/spies/fs.ts
new file mode 100644
index 000000000..6a4c91d4d
--- /dev/null
+++ b/apps/app-builder/src/__tests__/spies/fs.ts
@@ -0,0 +1,36 @@
+// make a spy for all methods on fs.promises that modify the file system
+import fs from 'fs';
+import {vi} from 'vitest';
+
+const fsAppendFile = vi.spyOn(fs, 'appendFile');
+const fsCopyFile = vi.spyOn(fs, 'copyFile');
+const fsMkdir = vi.spyOn(fs, 'mkdir');
+const fsRm = vi.spyOn(fs, 'rm');
+const fsRmdir = vi.spyOn(fs, 'rmdir');
+const fsUnlink = vi.spyOn(fs, 'unlink');
+const fsWriteFile = vi.spyOn(fs, 'writeFile');
+
+const fsPromisesAppendFile = vi.spyOn(fs.promises, 'appendFile');
+const fsPromisesCopyFile = vi.spyOn(fs.promises, 'copyFile');
+const fsPromisesMkdir = vi.spyOn(fs.promises, 'mkdir');
+const fsPromisesRm = vi.spyOn(fs.promises, 'rm');
+const fsPromisesRmdir = vi.spyOn(fs.promises, 'rmdir');
+const fsPromisesUnlink = vi.spyOn(fs.promises, 'unlink');
+const fsPromisesWriteFile = vi.spyOn(fs.promises, 'writeFile');
+
+export const fsModifyingMethodSpies = [
+  fsAppendFile,
+  fsCopyFile,
+  fsMkdir,
+  fsRm,
+  fsRmdir,
+  fsUnlink,
+  fsWriteFile,
+  fsPromisesAppendFile,
+  fsPromisesCopyFile,
+  fsPromisesMkdir,
+  fsPromisesRm,
+  fsPromisesRmdir,
+  fsPromisesUnlink,
+  fsPromisesWriteFile,
+] as const;
diff --git a/apps/app-builder/src/commands/clean.spec.ts b/apps/app-builder/src/commands/clean.spec.ts
new file mode 100644
index 000000000..3bae73d32
--- /dev/null
+++ b/apps/app-builder/src/commands/clean.spec.ts
@@ -0,0 +1,50 @@
+import {afterEach, describe, expect, it, vi} from 'vitest';
+import {exists} from '../utils';
+import {fsModifyingMethodSpies} from '../__tests__/spies/fs';
+import {mockFileSystem, restoreFileSystem} from '../__tests__/mockFileSystem';
+import {createTestContext} from '../__tests__/createTestContext';
+import {MOCK_ROOT_DIR} from '../__tests__/constants';
+import clean from './clean';
+
+describe('command: clean', () => {
+  afterEach(async () => {
+    await restoreFileSystem();
+    vi.restoreAllMocks();
+  });
+
+  it('does nothing when dry run is passed', async () => {
+    expect.assertions(fsModifyingMethodSpies.length);
+
+    await mockFileSystem({dist: {'text.txt': ''}});
+
+    await clean(createTestContext({args: {dryRun: true}}));
+
+    fsModifyingMethodSpies.forEach((spy) => {
+      expect(spy).not.toHaveBeenCalled();
+    });
+  });
+
+  it('does nothing when outDir does not exist', async () => {
+    expect.assertions(fsModifyingMethodSpies.length);
+
+    await mockFileSystem();
+
+    await clean(createTestContext());
+
+    fsModifyingMethodSpies.forEach((spy) => {
+      expect(spy).not.toHaveBeenCalled();
+    });
+  });
+
+  it('cleans dir', async () => {
+    expect.assertions(2);
+
+    await mockFileSystem({dist: {'text.txt': ''}});
+
+    expect(await exists(`${MOCK_ROOT_DIR}/dist/text.txt`)).toBe(true);
+
+    await clean(createTestContext({args: {dryRun: false}}));
+
+    expect(await exists(`${MOCK_ROOT_DIR}/dist/text.txt`)).toBe(false);
+  });
+});
diff --git a/apps/app-builder/src/utils/createDirectory.ts b/apps/app-builder/src/utils/createDirectory.ts
new file mode 100644
index 000000000..a4901e5ab
--- /dev/null
+++ b/apps/app-builder/src/utils/createDirectory.ts
@@ -0,0 +1,11 @@
+import {type MakeDirectoryOptions} from 'node:fs';
+import fs from 'fs';
+import {exists} from './exists';
+
+export const createDirectory = async (directory: string, options: MakeDirectoryOptions): Promise<void> => {
+  if (await exists(directory)) {
+    return;
+  }
+
+  await fs.promises.mkdir(directory, options);
+};
diff --git a/apps/app-builder/src/utils/index.ts b/apps/app-builder/src/utils/index.ts
index 6ee33fa92..67ae432b0 100644
--- a/apps/app-builder/src/utils/index.ts
+++ b/apps/app-builder/src/utils/index.ts
@@ -24,3 +24,4 @@ export * from './resolveFileName';
 export * from './resolveString';
 export * from './transformer';
 export * from './validateDistPath';
+export {createDirectory} from './createDirectory';