chore : add changeset for classDef style application

on-behalf-of: @Mermaid-Chart <hello@mermaidchart.com>

.changeset/chatty-insects-dream.md

@@ -0,0 +1,5 @@
+---
+'mermaid': patch
+---
+
+fix(treemap): Fixed treemap classDef style application to properly apply user-defined styles

docs/syntax/block.md

@@ -402,7 +402,7 @@ block
   blockArrowId4<["Label"]>(down)
   blockArrowId5<["Label"]>(x)
   blockArrowId6<["Label"]>(y)
-  blockArrowId7<["Label"]>(x, down)
+  blockArrowId6<["Label"]>(x, down)
 ```
 
 ```mermaid
@@ -413,7 +413,7 @@ block
   blockArrowId4<["Label"]>(down)
   blockArrowId5<["Label"]>(x)
   blockArrowId6<["Label"]>(y)
-  blockArrowId7<["Label"]>(x, down)
+  blockArrowId6<["Label"]>(x, down)
 ```
 
 #### Example - Space Blocks

packages/mermaid/src/diagrams/treemap/parser.ts

@@ -21,7 +21,7 @@ const populate = (ast: TreemapAst, db: TreemapDB) => {
     type: string;
     value?: number;
     classSelector?: string;
-    cssCompiledStyles?: string;
+    cssCompiledStyles?: string[];
   }[] = [];
 
   // Extract classes and styles from the treemap
@@ -44,7 +44,7 @@ const populate = (ast: TreemapAst, db: TreemapDB) => {
 
     // Get styles as a string if they exist
     const styles = item.classSelector ? db.getStylesForClass(item.classSelector) : [];
-    const cssCompiledStyles = styles.length > 0 ? styles.join(';') : undefined;
+    const cssCompiledStyles = styles.length > 0 ? styles : undefined;
 
     const itemData = {
       level,

packages/mermaid/src/diagrams/treemap/utils.ts

@@ -12,7 +12,7 @@ export function buildHierarchy(
     type: string;
     value?: number;
     classSelector?: string;
-    cssCompiledStyles?: string;
+    cssCompiledStyles?: string[];
   }[]
 ): TreemapNode[] {
   if (!items.length) {
@@ -29,7 +29,7 @@ export function buildHierarchy(
     };
     node.classSelector = item?.classSelector;
     if (item?.cssCompiledStyles) {
-      node.cssCompiledStyles = [item.cssCompiledStyles];
+      node.cssCompiledStyles = item.cssCompiledStyles;
     }
 
     if (item.type === 'Leaf' && item.value !== undefined) {

packages/mermaid/src/docs/syntax/block.md

@@ -283,7 +283,7 @@ block
   blockArrowId4<["Label"]>(down)
   blockArrowId5<["Label"]>(x)
   blockArrowId6<["Label"]>(y)
-  blockArrowId7<["Label"]>(x, down)
+  blockArrowId6<["Label"]>(x, down)
 ```
 
 #### Example - Space Blocks