[feat] Support Markdown rendering for node descriptions in NodePreview (#4684)

Co-authored-by: Claude <noreply@anthropic.com>

src/components/node/NodePreview.spec.ts

@@ -1,11 +1,12 @@
 import { mount } from '@vue/test-utils'
 import { createPinia } from 'pinia'
 import PrimeVue from 'primevue/config'
-import { beforeAll, describe, expect, it } from 'vitest'
+import { beforeAll, describe, expect, it, vi } from 'vitest'
 import { createApp } from 'vue'
 import { createI18n } from 'vue-i18n'
 
 import type { ComfyNodeDef as ComfyNodeDefV2 } from '@/schemas/nodeDef/nodeDefSchemaV2'
+import * as markdownRendererUtil from '@/utils/markdownRendererUtil'
 
 import NodePreview from './NodePreview.vue'
 
@@ -129,4 +130,164 @@ describe('NodePreview', () => {
 
     expect(headdot.classes()).toContain('pr-3')
   })
+
+  describe('Description Rendering', () => {
+    it('renders plain text description as HTML', () => {
+      const plainTextNodeDef: ComfyNodeDefV2 = {
+        ...mockNodeDef,
+        description: 'This is a plain text description'
+      }
+
+      const wrapper = mountComponent(plainTextNodeDef)
+      const description = wrapper.find('._sb_description')
+
+      expect(description.exists()).toBe(true)
+      expect(description.html()).toContain('This is a plain text description')
+    })
+
+    it('renders markdown description with formatting', () => {
+      const markdownNodeDef: ComfyNodeDefV2 = {
+        ...mockNodeDef,
+        description: '**Bold text** and *italic text* with `code`'
+      }
+
+      const wrapper = mountComponent(markdownNodeDef)
+      const description = wrapper.find('._sb_description')
+
+      expect(description.exists()).toBe(true)
+      expect(description.html()).toContain('<strong>Bold text</strong>')
+      expect(description.html()).toContain('<em>italic text</em>')
+      expect(description.html()).toContain('<code>code</code>')
+    })
+
+    it('does not render description element when description is empty', () => {
+      const noDescriptionNodeDef: ComfyNodeDefV2 = {
+        ...mockNodeDef,
+        description: ''
+      }
+
+      const wrapper = mountComponent(noDescriptionNodeDef)
+      const description = wrapper.find('._sb_description')
+
+      expect(description.exists()).toBe(false)
+    })
+
+    it('does not render description element when description is undefined', () => {
+      const { description, ...nodeDefWithoutDescription } = mockNodeDef
+      const wrapper = mountComponent(
+        nodeDefWithoutDescription as ComfyNodeDefV2
+      )
+      const descriptionElement = wrapper.find('._sb_description')
+
+      expect(descriptionElement.exists()).toBe(false)
+    })
+
+    it('calls renderMarkdownToHtml utility function', () => {
+      const spy = vi.spyOn(markdownRendererUtil, 'renderMarkdownToHtml')
+      const testDescription = 'Test **markdown** description'
+
+      const nodeDefWithDescription: ComfyNodeDefV2 = {
+        ...mockNodeDef,
+        description: testDescription
+      }
+
+      mountComponent(nodeDefWithDescription)
+
+      expect(spy).toHaveBeenCalledWith(testDescription)
+      spy.mockRestore()
+    })
+
+    it('handles potentially unsafe markdown content safely', () => {
+      const unsafeNodeDef: ComfyNodeDefV2 = {
+        ...mockNodeDef,
+        description:
+          'Safe **markdown** content <script>alert("xss")</script> with `code` blocks'
+      }
+
+      const wrapper = mountComponent(unsafeNodeDef)
+      const description = wrapper.find('._sb_description')
+
+      // The description should still exist because there's safe content
+      if (description.exists()) {
+        // Should not contain script tags (sanitized by DOMPurify)
+        expect(description.html()).not.toContain('<script>')
+        expect(description.html()).not.toContain('alert("xss")')
+        // Should contain the safe markdown content rendered as HTML
+        expect(description.html()).toContain('<strong>markdown</strong>')
+        expect(description.html()).toContain('<code>code</code>')
+      } else {
+        // If DOMPurify removes everything, that's also acceptable for security
+        expect(description.exists()).toBe(false)
+      }
+    })
+
+    it('handles markdown with line breaks', () => {
+      const multilineNodeDef: ComfyNodeDefV2 = {
+        ...mockNodeDef,
+        description: 'Line 1\n\nLine 3 after empty line'
+      }
+
+      const wrapper = mountComponent(multilineNodeDef)
+      const description = wrapper.find('._sb_description')
+
+      expect(description.exists()).toBe(true)
+      // Should contain paragraph tags for proper line break handling
+      expect(description.html()).toContain('<p>')
+    })
+
+    it('handles markdown lists', () => {
+      const listNodeDef: ComfyNodeDefV2 = {
+        ...mockNodeDef,
+        description: '- Item 1\n- Item 2\n- Item 3'
+      }
+
+      const wrapper = mountComponent(listNodeDef)
+      const description = wrapper.find('._sb_description')
+
+      expect(description.exists()).toBe(true)
+      expect(description.html()).toContain('<ul>')
+      expect(description.html()).toContain('<li>')
+    })
+
+    it('applies correct styling classes to description', () => {
+      const wrapper = mountComponent()
+      const description = wrapper.find('._sb_description')
+
+      expect(description.classes()).toContain('_sb_description')
+    })
+
+    it('uses v-html directive for rendered content', () => {
+      const htmlNodeDef: ComfyNodeDefV2 = {
+        ...mockNodeDef,
+        description: 'Content with **bold** text'
+      }
+
+      const wrapper = mountComponent(htmlNodeDef)
+      const description = wrapper.find('._sb_description')
+
+      // The component should render the HTML, not escape it
+      expect(description.html()).toContain('<strong>bold</strong>')
+      expect(description.html()).not.toContain('&lt;strong&gt;')
+    })
+
+    it('prevents XSS attacks by sanitizing dangerous HTML elements', () => {
+      const maliciousNodeDef: ComfyNodeDefV2 = {
+        ...mockNodeDef,
+        description:
+          'Normal text <img src="x" onerror="alert(\'XSS\')" /> and **bold** text'
+      }
+
+      const wrapper = mountComponent(maliciousNodeDef)
+      const description = wrapper.find('._sb_description')
+
+      if (description.exists()) {
+        // Should not contain dangerous event handlers
+        expect(description.html()).not.toContain('onerror')
+        expect(description.html()).not.toContain('alert(')
+        // Should still contain safe markdown content
+        expect(description.html()).toContain('<strong>bold</strong>')
+        // May or may not contain img tag depending on DOMPurify config
+      }
+    })
+  })
 })

src/components/node/NodePreview.vue

@@ -70,15 +70,14 @@ https://github.com/Nuked88/ComfyUI-N-Sidebar/blob/7ae7da4a9761009fb6629bc04c6830
       </div>
     </div>
     <div
-      v-if="nodeDef.description"
+      v-if="renderedDescription"
       class="_sb_description"
       :style="{
         color: litegraphColors.WIDGET_SECONDARY_TEXT_COLOR,
         backgroundColor: litegraphColors.WIDGET_BGCOLOR
       }"
-    >
-      {{ nodeDef.description }}
-    </div>
+      v-html="renderedDescription"
+    />
   </div>
 </template>
 
@@ -89,8 +88,9 @@ import { computed } from 'vue'
 import type { ComfyNodeDef as ComfyNodeDefV2 } from '@/schemas/nodeDef/nodeDefSchemaV2'
 import { useWidgetStore } from '@/stores/widgetStore'
 import { useColorPaletteStore } from '@/stores/workspace/colorPaletteStore'
+import { renderMarkdownToHtml } from '@/utils/markdownRendererUtil'
 
-const props = defineProps<{
+const { nodeDef } = defineProps<{
   nodeDef: ComfyNodeDefV2
 }>()
 
@@ -101,7 +101,12 @@ const litegraphColors = computed(
 
 const widgetStore = useWidgetStore()
 
-const nodeDef = props.nodeDef
+const { description } = nodeDef
+const renderedDescription = computed(() => {
+  if (!description) return ''
+  return renderMarkdownToHtml(description)
+})
+
 const allInputDefs = Object.values(nodeDef.inputs)
 const allOutputDefs = nodeDef.outputs
 const slotInputDefs = allInputDefs.filter(