// Before
const basePath = docPath
 ? outputDir.split(docPath!)[1].replace(/^\/+/g, "")
 : outputDir.slice(outputDir.indexOf("/", 1)).replace(/^\/+/g, "");
// After
const basePath = docPath
 ? (outputDir.split(docPath!)[1] || "").replace(/^\/+/g, "")
 : outputDir.slice(outputDir.indexOf("/", 1)).replace(/^\/+/g, "");
Motivation and Context
When configuring multiple @docusaurus/plugin-content-docs instances with different paths alongside
docusaurus-plugin-openapi-docs, the plugin crashes with:
TypeError: Cannot read properties of undefined (reading 'replace')
 at groupByTags (node_modules/docusaurus-plugin-openapi-docs/lib/sidebars/index.js:85:38)
This occurs because outputDir.split(docPath)[1] returns undefined when the outputDir path doesn't contain
docPath as expected. The code then attempts to call .replace() on undefined, causing the error.
Example configuration that triggers the bug:
plugins: [
 [
 '@docusaurus/plugin-content-docs',
 {
 id: 'WEDAApi',
 path: 'Weda/Api',
 routeBasePath: 'apis/weda',
 // ...
 },
 ],
 [
 'docusaurus-plugin-openapi-docs',
 {
 config: {
 weda: {
 specPath: "src/api/weda.yml",
 outputDir: "Weda/Api",
 sidebarOptions: {
 groupPathsBy: "tag",
 },
 }
 }
 }
 ],
]
The fix allows the plugin to gracefully handle mismatched path configurations by defaulting to an empty string
 when the split operation fails.
How Has This Been Tested?
Testing Environment:
- Node.js: v22.14.0
- Docusaurus: 3.9.1
- docusaurus-plugin-openapi-docs: 4.5.1
- OS: Windows 11
Test Steps:
1. Configured multiple docs plugin instances with different paths
2. Set up OpenAPI docs plugin with sidebarOptions.groupPathsBy: "tag"
3. Ran npx docusaurus gen-api-docs weda
4. Verified successful sidebar generation without errors
5. Started dev server with npm start
6. Confirmed API documentation displays correctly with proper tag-based categorization
Test Results:
- ✅ Sidebar generation completes without TypeError
- ✅ Tag-based sidebar structure generated correctly
- ✅ All API endpoints accessible and properly categorized
- ✅ Development server starts without errors
Before Fix: Command failed with TypeError: Cannot read properties of undefined (reading 'replace')
After Fix: All commands execute successfully, sidebar generated with 90+ API endpoints properly organized by
tags.
Screenshots (if appropriate)
N/A - This is a bug fix with no visual changes to the UI.
Types of changes
- Bug fix (non-breaking change which fixes an issue)