Merge pull request #4633 from ibrahimWassouf/bug/4592_fix_newLine_padding_class_diagram

Bug/4592 fix new line padding class diagram

cypress/integration/rendering/classDiagram.spec.js

@@ -423,4 +423,82 @@ describe('Class diagram', () => {
     );
     cy.get('svg');
   });
+
+  it('should render class diagram with newlines in title', () => {
+    imgSnapshotTest(`
+      classDiagram
+        Animal <|-- \`Du\nck\`
+        Animal : +int age
+        Animal : +String gender
+        Animal: +isMammal()
+        Animal: +mate()
+        class \`Du\nck\` {
+          +String beakColor
+          +String featherColor
+          +swim()
+          +quack()
+        }
+      `);
+    cy.get('svg');
+  });
+
+  it('should render class diagram with many newlines in title', () => {
+    imgSnapshotTest(`
+    classDiagram
+      class \`This\nTitle\nHas\nMany\nNewlines\` {
+        +String Also
+        -Stirng Many
+        #int Members
+        +And()
+        -Many()
+        #Methods()
+      }
+    `);
+  });
+
+  it('should render with newlines in title and an annotation', () => {
+    imgSnapshotTest(`
+    classDiagram
+      class \`This\nTitle\nHas\nMany\nNewlines\` {
+        +String Also
+        -Stirng Many
+        #int Members
+        +And()
+        -Many()
+        #Methods()
+      }
+      &lt;&lt;Interface&gt;&gt; \`This\nTitle\nHas\nMany\nNewlines\`  
+    `);
+  });
+
+  it('should handle newline title in namespace', () => {
+    imgSnapshotTest(`
+    classDiagram
+      namespace testingNamespace {
+      class \`This\nTitle\nHas\nMany\nNewlines\` {
+        +String Also
+        -Stirng Many
+        #int Members
+        +And()
+        -Many()
+        #Methods()
+      }
+    }
+    `);
+  });
+
+  it('should handle newline in string label', () => {
+    imgSnapshotTest(`
+      classDiagram
+        class A["This has\na newline!"] {
+          +String boop
+          -Int beep
+          #double bop
+        }
+
+        class B["This title also has\na newline"]
+        B : +with(more)
+        B : -methods()
+      `);
+  });
 });

packages/mermaid/src/dagre-wrapper/nodes.js

@@ -917,7 +917,9 @@ const class_box = (parent, node) => {
         ((-1 * maxHeight) / 2 + verticalPos + lineHeight / 2) +
         ')'
     );
-    verticalPos += classTitleBBox.height + rowPadding;
+    //get the height of the bounding box of each member if exists
+    const memberBBox = lbl?.getBBox();
+    verticalPos += (memberBBox?.height ?? 0) + rowPadding;
   });
 
   verticalPos += lineHeight;
@@ -935,7 +937,8 @@ const class_box = (parent, node) => {
       'transform',
       'translate( ' + -maxWidth / 2 + ', ' + ((-1 * maxHeight) / 2 + verticalPos) + ')'
     );
-    verticalPos += classTitleBBox.height + rowPadding;
+    const memberBBox = lbl?.getBBox();
+    verticalPos += (memberBBox?.height ?? 0) + rowPadding;
   });
 
   rect