Markdown editor fix (#19732)

* fix block editor escaping html elements

* add unit tests

openmetadata-ui/src/main/resources/ui/src/utils/BlockEditorUtils.test.ts

@@ -14,6 +14,7 @@ import {
   formatValueBasedOnContent,
   getHtmlStringFromMarkdownString,
   getTextFromHtmlString,
+  isHTMLString,
 } from './BlockEditorUtils';
 
 describe('getTextFromHtmlString', () => {
@@ -132,3 +133,59 @@ describe('formatValueBasedOnContent', () => {
     expect(formatValueBasedOnContent(input)).toBe('');
   });
 });
+
+describe('isHTMLString', () => {
+  it('should return true for simple HTML content', () => {
+    const htmlContent = '<p>This is a paragraph</p>';
+
+    expect(isHTMLString(htmlContent)).toBe(true);
+  });
+
+  it('should return true for complex HTML content', () => {
+    const htmlContent = `
+      <div class="container">
+        <h1>Title</h1>
+        <p>This is a <strong>bold</strong> paragraph with <a href="#">link</a></p>
+        <ul>
+          <li>Item 1</li>
+          <li>Item 2</li>
+        </ul>
+      </div>
+    `;
+
+    expect(isHTMLString(htmlContent)).toBe(true);
+  });
+
+  it('should return false for markdown content', () => {
+    const markdownContent = `
+      ***
+### Data Sharing Policies
+If there is any question or concern regarding the data sharing policies, 
+please contact the support team <test@test.com>.
+***
+    `;
+
+    expect(isHTMLString(markdownContent)).toBe(false);
+  });
+
+  it('should return false for plain text', () => {
+    const plainText = 'This is just plain text without any formatting';
+
+    expect(isHTMLString(plainText)).toBe(false);
+  });
+
+  it('should return false for empty string', () => {
+    expect(isHTMLString('')).toBe(false);
+  });
+
+  it('should return false when content has both HTML and markdown', () => {
+    const mixedContent = `
+      <div>
+        # Markdown Header
+        * List item
+      </div>
+    `;
+
+    expect(isHTMLString(mixedContent)).toBe(true);
+  });
+});

openmetadata-ui/src/main/resources/ui/src/utils/BlockEditorUtils.ts

@@ -122,12 +122,40 @@ export const formatValueBasedOnContent = (value: string) =>
   value === '<p></p>' ? '' : value;
 
 export const isHTMLString = (content: string) => {
+  // Quick check for common HTML tags
+  const commonHtmlTags =
+    /<(p|div|span|a|ul|ol|li|h[1-6]|br|strong|em|code|pre)[>\s]/i;
+
+  // If content doesn't have any HTML-like structure, return false early
+  if (!commonHtmlTags.test(content)) {
+    return false;
+  }
+
   try {
     const parser = new DOMParser();
     const parsedDocument = parser.parseFromString(content, 'text/html');
 
-    // since text can be also counted as child node so we will check if length is greater than 1
-    return parsedDocument.body.childNodes.length > 1;
+    // Check if there are any actual HTML elements (not just text nodes)
+    const hasHtmlElements = Array.from(parsedDocument.body.childNodes).some(
+      (node) => node.nodeType === Node.ELEMENT_NODE
+    );
+
+    // Check if the content has markdown-specific patterns
+    const markdownPatterns = [
+      /^#{1,6}\s/, // Headers
+      /^\s*[-*+]\s/, // Lists
+      /^\s*\d+\.\s/, // Numbered lists
+      /^\s*>{1,}\s/, // Blockquotes
+      /^---|\*\*\*|___/, // Horizontal rules
+      /`{1,3}[^`]+`{1,3}/, // Code blocks
+    ];
+
+    const hasMarkdownSyntax = markdownPatterns.some((pattern) =>
+      pattern.test(content)
+    );
+
+    // If it has markdown syntax but also parsed as HTML, prefer markdown interpretation
+    return hasHtmlElements && !hasMarkdownSyntax;
   } catch (e) {
     return false;
   }