From 00c90984e5af4c0e1b0f60c641210d529e332e22 Mon Sep 17 00:00:00 2001
From: Kiss Miklos <miklos@roadie.io>
Date: Tue, 23 Jan 2024 16:49:16 +0100
Subject: [PATCH] add possibility to configure nunjucks configs

Signed-off-by: Kiss Miklos <miklos@roadie.io>
---
 .../src/lib/templating/SecureTemplater.ts                  | 7 +++++++
 .../src/scaffolder/actions/builtin/fetch/template.ts       | 6 ++++++
 plugins/scaffolder-node/src/index.ts                       | 2 +-
 plugins/scaffolder-node/src/types.ts                       | 3 +++
 4 files changed, 17 insertions(+), 1 deletion(-)

diff --git a/plugins/scaffolder-backend/src/lib/templating/SecureTemplater.ts b/plugins/scaffolder-backend/src/lib/templating/SecureTemplater.ts
index 701863c7f6..8323b4aa98 100644
--- a/plugins/scaffolder-backend/src/lib/templating/SecureTemplater.ts
+++ b/plugins/scaffolder-backend/src/lib/templating/SecureTemplater.ts
@@ -19,6 +19,7 @@ import { resolvePackagePath } from '@backstage/backend-common';
 import {
   TemplateFilter as _TemplateFilter,
   TemplateGlobal as _TemplateGlobal,
+  NunjucksConfigs,
 } from '@backstage/plugin-scaffolder-node';
 import fs from 'fs-extra';
 import { JsonValue } from '@backstage/types';
@@ -34,6 +35,7 @@ const { render, renderCompat } = (() => {
 
   const env = module.exports.configure({
     autoescape: false,
+    ...JSON.parse(nunjucksConfigs),
     tags: {
       variableStart: '\${{',
       variableEnd: '}}',
@@ -42,6 +44,7 @@ const { render, renderCompat } = (() => {
 
   const compatEnv = module.exports.configure({
     autoescape: false,
+    ...JSON.parse(nunjucksConfigs),
     tags: {
       variableStart: '{{',
       variableEnd: '}}',
@@ -109,6 +112,7 @@ export interface SecureTemplaterOptions {
   templateFilters?: Record<string, TemplateFilter>;
   /* Extra user-provided nunjucks globals */
   templateGlobals?: Record<string, TemplateGlobal>;
+  nunjucksConfigs?: NunjucksConfigs;
 }
 
 export type SecureTemplateRenderer = (
@@ -122,6 +126,7 @@ export class SecureTemplater {
       cookiecutterCompat,
       templateFilters = {},
       templateGlobals = {},
+      nunjucksConfigs = {},
     } = options;
 
     const isolate = new Isolate({ memoryLimit: 128 });
@@ -140,6 +145,8 @@ export class SecureTemplater {
       mkScript(nunjucksSource),
     );
 
+    await contextGlobal.set('nunjucksConfigs', JSON.stringify(nunjucksConfigs));
+
     const availableFilters = Object.keys(templateFilters);
 
     await contextGlobal.set(
diff --git a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/fetch/template.ts b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/fetch/template.ts
index 26b249b76d..2a2c138708 100644
--- a/plugins/scaffolder-backend/src/scaffolder/actions/builtin/fetch/template.ts
+++ b/plugins/scaffolder-backend/src/scaffolder/actions/builtin/fetch/template.ts
@@ -69,6 +69,8 @@ export function createFetchTemplateAction(options: {
     copyWithoutTemplating?: string[];
     cookiecutterCompat?: boolean;
     replace?: boolean;
+    trimBlocks?: boolean;
+    lstripBlocks?: boolean;
   }>({
     id: 'fetch:template',
     description:
@@ -237,6 +239,10 @@ export function createFetchTemplateAction(options: {
           ...additionalTemplateFilters,
         },
         templateGlobals: additionalTemplateGlobals,
+        nunjucksConfigs: {
+          trimBlocks: ctx.input.trimBlocks,
+          lstripBlocks: ctx.input.lstripBlocks,
+        },
       });
 
       for (const location of allEntriesInTemplate) {
diff --git a/plugins/scaffolder-node/src/index.ts b/plugins/scaffolder-node/src/index.ts
index 0ec492dd32..a049ffd9b7 100644
--- a/plugins/scaffolder-node/src/index.ts
+++ b/plugins/scaffolder-node/src/index.ts
@@ -23,4 +23,4 @@
 export * from './actions';
 export * from './tasks';
 export * from './files';
-export type { TemplateFilter, TemplateGlobal } from './types';
+export type { TemplateFilter, TemplateGlobal, NunjucksConfigs } from './types';
diff --git a/plugins/scaffolder-node/src/types.ts b/plugins/scaffolder-node/src/types.ts
index bae106c84e..892570af80 100644
--- a/plugins/scaffolder-node/src/types.ts
+++ b/plugins/scaffolder-node/src/types.ts
@@ -23,3 +23,6 @@ export type TemplateFilter = (...args: JsonValue[]) => JsonValue | undefined;
 export type TemplateGlobal =
   | ((...args: JsonValue[]) => JsonValue | undefined)
   | JsonValue;
+
+/** @public */
+export type NunjucksConfigs = { trimBlocks?: boolean; lstripBlocks?: boolean };