From 0f58402454bd6a089f0a06741a3afea4cd9c0aed Mon Sep 17 00:00:00 2001
From: Alex Eftimie <alex.eftimie@getyourguide.com>
Date: Mon, 12 Jun 2023 00:08:07 +0200
Subject: [PATCH] Update docs. Fix tsc

Signed-off-by: Alex Eftimie <alex.eftimie@getyourguide.com>
---
 .../software-templates/writing-templates.md   | 22 +++++++++++++++++++
 .../tasks/NunjucksWorkflowRunner.ts           |  4 ++--
 2 files changed, 24 insertions(+), 2 deletions(-)

diff --git a/docs/features/software-templates/writing-templates.md b/docs/features/software-templates/writing-templates.md
index 67bcb6c179..81418faf21 100644
--- a/docs/features/software-templates/writing-templates.md
+++ b/docs/features/software-templates/writing-templates.md
@@ -495,6 +495,7 @@ template. These follow the same standard format:
 - id: fetch-base # A unique id for the step
   name: Fetch Base # A title displayed in the frontend
   if: ${{ parameters.name }} # Optional condition, skip the step if not truthy
+  each: ${{ parameters.iterable }} # Optional iterable, run the same step multiple times
   action: fetch:template # An action to call
   input: # Input that is passed as arguments to the action handler
     url: ./template
@@ -506,6 +507,27 @@ By default we ship some [built in actions](./builtin-actions.md) that you can
 take a look at, or you can
 [create your own custom actions](./writing-custom-actions.md).
 
+When `each` is provided, the current iteration value is available in the `${{ each }}` input.
+
+Examples:
+
+```yaml
+each: ['apples', 'oranges']
+input:
+  values:
+    fruit: ${{ each}}
+```
+
+```yaml
+each: [{ name: 'apple', count: 3 }, { name: 'orange', count: 1 }]
+input:
+  values:
+    fruit: ${{ each.name }}
+    count: ${{ each.count }}
+```
+
+When `each` is used, the outputs of a repeated step are returned as an array of outputs from each iteration.
+
 ## Outputs
 
 Each individual step can output some variables that can be used in the
diff --git a/plugins/scaffolder-backend/src/scaffolder/tasks/NunjucksWorkflowRunner.ts b/plugins/scaffolder-backend/src/scaffolder/tasks/NunjucksWorkflowRunner.ts
index e3233483ef..a6c486c58d 100644
--- a/plugins/scaffolder-backend/src/scaffolder/tasks/NunjucksWorkflowRunner.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/tasks/NunjucksWorkflowRunner.ts
@@ -25,7 +25,7 @@ import * as winston from 'winston';
 import fs from 'fs-extra';
 import path from 'path';
 import nunjucks from 'nunjucks';
-import { JsonObject, JsonValue } from '@backstage/types';
+import { JsonArray, JsonObject, JsonValue } from '@backstage/types';
 import { InputError, NotAllowedError } from '@backstage/errors';
 import { PassThrough } from 'stream';
 import { generateExampleOutput, isTruthy } from './helper';
@@ -351,7 +351,7 @@ export class NunjucksWorkflowRunner implements WorkflowRunner {
           output(name: string, value: JsonValue) {
             if (step.each) {
               stepOutput[name] = stepOutput[name] || [];
-              stepOutput[name].push(value);
+              (stepOutput[name] as JsonArray).push(value);
             } else {
               stepOutput[name] = value;
             }