handle case where cwd is set to dir created with mkdir

src/batch.ts

@@ -164,7 +164,7 @@ export default class Batch {
     function next(): void {
       const latestFn = batch.shift();
       if (!latestFn) return;
-      if (latestFn.length) {
+      if (latestFn.length && typeof latestFn === 'function') {
         latestFn(next);
         return;
       }

src/expectations.ts

@@ -40,10 +40,12 @@ function error(
   if (actual) err.actual = actual;
 
   // Use expect to show diffs between actual and expected values
-  try {
-    expect(actual).toEqual(expected);
-  } catch (e) {
-    console.log(e.message);
+  if (typeof expected === 'string') {
+    try {
+      expect(actual).toEqual(expected);
+    } catch (e) {
+      console.log(e.message);
+    }
   }
 
   // Show the stdout if the command errored

src/runner.ts

@@ -1,3 +1,4 @@
+import fs from 'fs';
 import clone from 'clone';
 import { spawn } from 'child_process';
 import AssertionError from 'assertion-error';
@@ -210,8 +211,13 @@ export default class Runner {
    * @returns instance for chaining
    */
 
-  public cwd(path: string): Runner {
-    this.environment.cwd = path;
+  public cwd(cwdPath: string): Runner {
+    this.batch.add(() => {
+      if (!fs.existsSync(cwdPath)) {
+        throw new Error(`The path "${cwdPath}" does not exist`);
+      }
+      this.environment.cwd = cwdPath;
+    });
     return this;
   }
 

tests/cwd.test.ts

@@ -0,0 +1,42 @@
+import path from 'path';
+import fs from 'fs';
+import os from 'os';
+import { Joker } from '.';
+
+describe('Joker#cwd', () => {
+  it('should accept given path', async () => {
+    const tmpDir = path.join(
+      os.tmpdir(),
+      String(Math.floor(Math.random() * 100))
+    );
+    fs.mkdirSync(tmpDir);
+    await new Joker()
+      .cwd(tmpDir)
+      .run('echo foo')
+      .end();
+  });
+
+  it('should change allow changing cwd to created dir', async () => {
+    const tmpDir = path.join(
+      os.tmpdir(),
+      String(Math.floor(Math.random() * 100))
+    );
+    expect(fs.existsSync(tmpDir)).toBe(false);
+    await new Joker()
+      .mkdir(tmpDir)
+      .cwd(tmpDir)
+      .run('echo foo')
+      .rmdir(tmpDir)
+      .end();
+    expect(fs.existsSync(tmpDir)).toBe(false);
+  });
+
+  it('should fail if given path does not exist', async () => {
+    await expect(
+      new Joker()
+        .cwd('non_existent_path')
+        .run('echo foo')
+        .end()
+    ).rejects.toThrow('The path "non_existent_path" does not exist');
+  });
+});