From e9ce8cf4da9062d85098042044822100889bb0dd Mon Sep 17 00:00:00 2001
From: Krishna Upadhyay <24423580+kriss-u@users.noreply.github.com>
Date: Thu, 10 Jul 2025 21:39:19 -0500
Subject: [PATCH] fix: trim the direction string in flowchart

---
 .changeset/smart-humans-cover.md                  | 5 +++++
 packages/mermaid/src/diagrams/flowchart/flowDb.ts | 3 ++-
 2 files changed, 7 insertions(+), 1 deletion(-)
 create mode 100644 .changeset/smart-humans-cover.md

diff --git a/.changeset/smart-humans-cover.md b/.changeset/smart-humans-cover.md
new file mode 100644
index 000000000..4408e0a9c
--- /dev/null
+++ b/.changeset/smart-humans-cover.md
@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix: Update flowchart direction TD's behavior to be the same as TB
diff --git a/packages/mermaid/src/diagrams/flowchart/flowDb.ts b/packages/mermaid/src/diagrams/flowchart/flowDb.ts
index 65f8c4a05..303ad0e66 100644
--- a/packages/mermaid/src/diagrams/flowchart/flowDb.ts
+++ b/packages/mermaid/src/diagrams/flowchart/flowDb.ts
@@ -403,7 +403,8 @@ You have to call mermaid.initialize.`
    *
    */
   public setDirection(dir: string) {
-    this.direction = dir;
+    this.direction = dir.trim();
+
     if (/.*</.exec(this.direction)) {
       this.direction = 'RL';
     }