From c18a3c2ae035f3e94bc7c6e621929e0e5dd8141e Mon Sep 17 00:00:00 2001
From: Dominik Henneke <dominik.henneke@sda-se.com>
Date: Fri, 18 Jun 2021 15:43:19 +0200
Subject: [PATCH] Correctly recognize whether the cookiecutter command exists

Signed-off-by: Dominik Henneke <dominik.henneke@sda-se.com>
---
 .changeset/weak-needles-peel.md                              | 5 +++++
 .../src/scaffolder/stages/templater/cookiecutter.test.ts     | 3 ++-
 .../src/scaffolder/stages/templater/cookiecutter.ts          | 5 ++++-
 3 files changed, 11 insertions(+), 2 deletions(-)
 create mode 100644 .changeset/weak-needles-peel.md

diff --git a/.changeset/weak-needles-peel.md b/.changeset/weak-needles-peel.md
new file mode 100644
index 0000000000..5315e2cb66
--- /dev/null
+++ b/.changeset/weak-needles-peel.md
@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-backend': patch
+---
+
+Correctly recognize whether the cookiecutter command exists
diff --git a/plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.test.ts b/plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.test.ts
index a9227c742e..b040f8760c 100644
--- a/plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.test.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.test.ts
@@ -35,6 +35,7 @@ describe('CookieCutter Templater', () => {
 
   beforeEach(() => {
     jest.clearAllMocks();
+    commandExists.mockRejectedValue(null);
   });
 
   it('should write a cookiecutter.json file with the values from the entity', async () => {
@@ -228,7 +229,7 @@ describe('CookieCutter Templater', () => {
       };
 
       jest.spyOn(fs, 'readdir').mockResolvedValueOnce(['newthing'] as any);
-      commandExists.mockImplementationOnce(() => () => true);
+      commandExists.mockResolvedValueOnce(true);
 
       const templater = new CookieCutter({ containerRunner });
       await templater.run({
diff --git a/plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.ts b/plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.ts
index c0abc44521..5809f7a60e 100644
--- a/plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/stages/templater/cookiecutter.ts
@@ -70,7 +70,10 @@ export class CookieCutter implements TemplaterBase {
       [intermediateDir]: '/output',
     };
 
-    const cookieCutterInstalled = await commandExists('cookiecutter');
+    // the command-exists package returns `true` or throws an error
+    const cookieCutterInstalled = await commandExists('cookiecutter').catch(
+      () => false,
+    );
     if (cookieCutterInstalled) {
       await runCommand({
         command: 'cookiecutter',