Merge pull request #6855 from mermaid-js/sidv/showRawData

fix: fallback to raw text instead of rendering *Unsupported markdown*

.changeset/strong-laws-confess.md

@@ -0,0 +1,9 @@
+---
+'mermaid': patch
+---
+
+fix: fallback to raw text instead of rendering _Unsupported markdown_ or empty blocks
+
+Instead of printing **Unsupported markdown: XXX**, or empty blocks when using a markdown feature
+that Mermaid does not yet support when `htmlLabels: true`(default) or `htmlLabels: false`,
+fallback to the raw markdown text.

cypress/integration/rendering/flowchart-v2.spec.js

@@ -1164,4 +1164,26 @@ end
       `
     );
   });
+
+  describe('when rendering unsuported markdown', () => {
+    const graph = `flowchart TB
+    mermaid{"What is\nyourmermaid version?"} --> v10["<11"] --"\`<**1**1\`"--> fine["No bug"]
+    mermaid --> v11[">= v11"] -- ">= v11" --> broken["Affected by https://github.com/mermaid-js/mermaid/issues/5824"]
+    subgraph subgraph1["\`How to fix **fix**\`"]
+        broken --> B["B"]
+    end
+    githost["Github, Gitlab, BitBucket, etc."]
+    githost2["\`Github, Gitlab, BitBucket, etc.\`"]
+    a["1."]
+    b["- x"]
+      `;
+
+    it('should render raw strings', () => {
+      imgSnapshotTest(graph);
+    });
+
+    it('should render raw strings with htmlLabels: false', () => {
+      imgSnapshotTest(graph, { htmlLabels: false });
+    });
+  });
 });

packages/mermaid/src/rendering-util/handle-markdown-text.spec.ts

@@ -285,7 +285,11 @@ test('markdownToHTML - Unsupported formatting', () => {
   - l1
   - l2
   - l3`)
-  ).toMatchInlineSnapshot('"<p>Hello</p>Unsupported markdown: list"');
+  ).toMatchInlineSnapshot(`
+    "<p>Hello</p>  - l1
+      - l2
+      - l3"
+  `);
 });
 
 test('markdownToHTML - no auto wrapping', () => {

packages/mermaid/src/rendering-util/handle-markdown-text.ts

@@ -3,6 +3,7 @@ import { marked } from 'marked';
 import { dedent } from 'ts-dedent';
 import type { MarkdownLine, MarkdownWordType } from './types.js';
 import type { MermaidConfig } from '../config.type.js';
+import { log } from '../logger.js';
 
 /**
  * @param markdown - markdown to process
@@ -61,6 +62,8 @@ export function markdownToLines(markdown: string, config: MermaidConfig = {}): M
       });
     } else if (treeNode.type === 'html') {
       lines[currentLine].push({ content: treeNode.text, type: 'normal' });
+    } else {
+      lines[currentLine].push({ content: treeNode.raw, type: 'normal' });
     }
   });
 
@@ -89,7 +92,8 @@ export function markdownToHTML(markdown: string, { markdownAutoWrap }: MermaidCo
     } else if (node.type === 'escape') {
       return node.text;
     }
-    return `Unsupported markdown: ${node.type}`;
+    log.warn(`Unsupported markdown: ${node.type}`);
+    return node.raw;
   }
 
   return nodes.map(output).join('');