navigation to '/index.html' with a static web server duplicates the page's content.

[bishabosha]

Have you read the Contributing Guidelines on issues?

• I have read the Contributing Guidelines on issues.

Prerequisites

• I'm using the latest version of Docusaurus.
• I have tried the npm run clear or yarn clear command.
• I have tried rm -rf node_modules yarn.lock package-lock.json and re-installing packages.
• I have tried creating a repro with https://new.docusaurus.io.
• I have read the console error message carefully (if applicable).

Description

when using a static web servers, such as GitHub pages, or static-web-server, and using the theme from preset-classic, navigation to the url /index.html will render the page twice, where the second is appended as a child to the end of the __docusaurus div. This even affects the official Docusaurus website at https://docusaurus.io/index.html

Reproducible demo

https://github.com/sbt/website

Steps to reproduce

1. check out commit 710848 of sbt/website
2. follow the steps in README.md (Docusaurus section) (i.e. yarn install, then yarn run build)
3. use a static web server to serve the generated build directory, I use static-web-server and port 8080
4. in a browser, such as Google Chrome, navigate to localhost:8080/index.html
5. observe the duplication of the index page content.

Expected behavior

It should render identically to / route, i.e. no duplication.

Actual behavior

the page's content is duplicated as the last child of the div with id __docusaurus.

Your environment

• Public source code: sbt/website@7108487
• Public site URL: https://www.scala-sbt.org/index.html
• Docusaurus version used: 3.1.0 (also tested with 3.1.1)
• Environment name and version: Chrome Version 121.0.6167.184 (Official Build) (arm64)
• Operating system and version: macOS Sonoma 14.2.1 (23C71)

Self-service

• I'd be willing to fix this bug myself.

[slorber]

This is a duplicate of #9552

See my answer here: #9552 (comment)

Pages should be served through their canonical urls, and by default, the canonical urls we define for pages do not have a .html extension.

Serving the same page from multiple urls (/xyz, /xyz/, /xyz.html, /xyz/index.html, and any other 200 reverse proxy you set up) is likely to cause troubles.

If this is a problem for you, you should either:

• configure your host to redirect from /xyz.html to the canonical url /xyz)
• use slug: "xyz.html" to define the html url as the canonical one

[bishabosha]

Thank you for the quick response