Merge pull request #6078 from backstage/fix/fixing-undefined-issue

Don't make `inputs` `undefined` when they are `""`

.changeset/unlucky-peas-nail.md

@@ -0,0 +1,5 @@
+---
+'@backstage/plugin-scaffolder-backend': patch
+---
+
+Keep the empty string as empty string in `input` rather than replacing with `undefined` to make empty values ok for `cookiecutter`

plugins/scaffolder-backend/src/scaffolder/tasks/TaskWorker.ts

@@ -170,11 +170,6 @@ export class TaskWorker {
                   preventIndent: true,
                 })(templateCtx);
 
-                // If it's just an empty string, treat it as undefined
-                if (templated === '') {
-                  return undefined;
-                }
-
                 // If it smells like a JSON object then give it a parse as an object and if it fails return the string
                 if (
                   (templated.startsWith('"') && templated.endsWith('"')) ||
@@ -213,6 +208,10 @@ export class TaskWorker {
           // Keep track of all tmp dirs that are created by the action so we can remove them after
           const tmpDirs = new Array<string>();
 
+          this.options.logger.debug(`Running ${action.id} with input`, {
+            input: JSON.stringify(input, null, 2),
+          });
+
           await action.handler({
             baseUrl: task.spec.baseUrl,
             logger: taskLogger,