From 457b77dd485f08616bd597492cdc26ed89ae92d3 Mon Sep 17 00:00:00 2001
From: Emile Bangma <github@emilebangma.com>
Date: Sat, 22 Mar 2025 03:59:43 +0100
Subject: [PATCH] fix(frontmatter): prevent slug duplication through
 frontmatter (#1860)

* fix(frontmatter): prevent slug duplication through frontmatter

* Simplify duplicate slug checks

* Update quartz/plugins/transformers/frontmatter.ts

Co-authored-by: Jacky Zhao <j.zhao2k19@gmail.com>

* lint

---------

Co-authored-by: Jacky Zhao <j.zhao2k19@gmail.com>
---
 quartz/plugins/transformers/frontmatter.ts | 4 ++++
 1 file changed, 4 insertions(+)

diff --git a/quartz/plugins/transformers/frontmatter.ts b/quartz/plugins/transformers/frontmatter.ts
index c04c52a..ce57428 100644
--- a/quartz/plugins/transformers/frontmatter.ts
+++ b/quartz/plugins/transformers/frontmatter.ts
@@ -114,6 +114,10 @@ export const FrontMatter: QuartzTransformerPlugin<Partial<Options>> = (userOpts)
 
             if (socialImage) data.socialImage = socialImage
 
+            // Remove duplicate slugs
+            const uniqueSlugs = [...new Set(allSlugs)]
+            allSlugs.splice(0, allSlugs.length, ...uniqueSlugs)
+
             // fill in frontmatter
             file.data.frontmatter = data as QuartzPluginData["frontmatter"]
           }