From 6e8827146e670ff8114600858d91c2a7d0ce4dfb Mon Sep 17 00:00:00 2001
From: Miroma <its.miroma@proton.me>
Date: Mon, 6 Apr 2026 23:43:38 +0200
Subject: [PATCH] fix(md)!: warn if region not found

when a region is not in the source file,
instead of including the whole file,
warn that the #region was not found in it.

fix #4625
---
 src/node/markdown/plugins/snippet.ts |  4 ++++
 src/node/utils/processIncludes.ts    | 10 +++++++---
 2 files changed, 11 insertions(+), 3 deletions(-)

diff --git a/src/node/markdown/plugins/snippet.ts b/src/node/markdown/plugins/snippet.ts
index 2acbf4c0f..c3ede0e2d 100644
--- a/src/node/markdown/plugins/snippet.ts
+++ b/src/node/markdown/plugins/snippet.ts
@@ -218,6 +218,10 @@ export const snippetPlugin = (md: MarkdownItAsync, srcDir: string) => {
             )
             .join('\n')
         )
+      } else {
+        token.content = `No region #${region} found in path: ${src}`
+        token.info = ''
+        return fence(...args)
       }
     }
 
diff --git a/src/node/utils/processIncludes.ts b/src/node/utils/processIncludes.ts
index 97d3d987c..a3b847489 100644
--- a/src/node/utils/processIncludes.ts
+++ b/src/node/utils/processIncludes.ts
@@ -70,9 +70,13 @@ export function processIncludes(
         }
       }
 
-      content = regions
-        .flatMap((region) => lines.slice(region.start, region.end))
-        .join('\n')
+      if (regions.length > 0) {
+        content = regions
+          .flatMap((region) => lines.slice(region.start, region.end))
+          .join('\n')
+      } else {
+        content = `No region or heading #${region} found in path: ${includePath}`
+      }
     }
 
     if (range) {