From c99bce6bab4c7ce0b81b66d44f44853ce4aeb1c3 Mon Sep 17 00:00:00 2001
From: Krishna Upadhyay <24423580+kriss-u@users.noreply.github.com>
Date: Mon, 4 Aug 2025 16:56:55 -0500
Subject: [PATCH] fix: add classLiteral to the language for class diagram
 namespace

---
 .changeset/rare-women-fly.md                        |  5 +++++
 cypress/integration/rendering/classDiagram.spec.js  | 13 +++++++++++++
 .../mermaid/src/diagrams/class/parser/class.spec.js |  8 ++++++++
 .../src/diagrams/class/parser/classDiagram.jison    |  1 +
 4 files changed, 27 insertions(+)
 create mode 100644 .changeset/rare-women-fly.md

diff --git a/.changeset/rare-women-fly.md b/.changeset/rare-women-fly.md
new file mode 100644
index 000000000..46d08dd10
--- /dev/null
+++ b/.changeset/rare-women-fly.md
@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix: Add escaped class literal name on namespace
diff --git a/cypress/integration/rendering/classDiagram.spec.js b/cypress/integration/rendering/classDiagram.spec.js
index f66a2d6f3..bd2a96b34 100644
--- a/cypress/integration/rendering/classDiagram.spec.js
+++ b/cypress/integration/rendering/classDiagram.spec.js
@@ -512,4 +512,17 @@ describe('Class diagram', () => {
       );
     });
   });
+
+  it('should handle backticks for namespace and class names', () => {
+    imgSnapshotTest(
+      `
+      classDiagram
+          namespace \`A::B\` {
+              class \`IPC::Sender\`
+          }
+          RenderProcessHost --|> \`IPC::Sender\`
+      `,
+      {}
+    );
+  });
 });
diff --git a/packages/mermaid/src/diagrams/class/parser/class.spec.js b/packages/mermaid/src/diagrams/class/parser/class.spec.js
index fe0077a29..7d4922561 100644
--- a/packages/mermaid/src/diagrams/class/parser/class.spec.js
+++ b/packages/mermaid/src/diagrams/class/parser/class.spec.js
@@ -15,4 +15,12 @@ describe('class diagram', function () {
       expect(() => parser.parse(`classDiagram\nnamespace ${prop} {\n\tclass A\n}`)).not.toThrow();
     });
   });
+
+  describe('backtick escaping', function () {
+    it('should handle backtick-quoted namespace names', function () {
+      expect(() =>
+        parser.parse(`classDiagram\nnamespace \`A::B\` {\n\tclass \`IPC::Sender\`\n}`)
+      ).not.toThrow();
+    });
+  });
 });
diff --git a/packages/mermaid/src/diagrams/class/parser/classDiagram.jison b/packages/mermaid/src/diagrams/class/parser/classDiagram.jison
index 83d9bd48e..0f971c8b9 100644
--- a/packages/mermaid/src/diagrams/class/parser/classDiagram.jison
+++ b/packages/mermaid/src/diagrams/class/parser/classDiagram.jison
@@ -242,6 +242,7 @@ classLabel
 
 namespaceName
     : alphaNumToken { $$=$1; }
+    | classLiteralName { $$=$1; }
     | alphaNumToken DOT namespaceName { $$=$1+'.'+$3; }
     | alphaNumToken namespaceName { $$=$1+$2; }
     ;