client-redirects-plugin doesn't support hash fragments in FROM attribute

[ZenaMel]

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

Based on the PR 9171 (issue #6845) This should be solved but isn't in Docusaurus v3.7.0 ("@docusaurus/plugin-client-redirects": "^3.7.0")

Stacktrace:

[ERROR] [Error [ValidationError]: "redirects[0].from" (/Load-Management/DLM/#hierarchial-dlm) is not a valid pathname. Pathname should start with slash and not contain any domain or query string.] {
  _original: {
    fromExtensions: [ 'html', 'htm' ],
    redirects: [
      {
        from: '/Load-Management/DLM/#hierarchial-dlm',
        to: '/Load-Management/DLM/dlm-hierarchical'
      },
      {
        from: '/Load-Management/DLM/#solar-dlm',
        to: '/Load-Management/DLM/dlm-solar'
      }
    ]
  },
  details: [
    {
      message: '"redirects[0].from" (/Load-Management/DLM/#hierarchial-dlm) is not a valid pathname. Pathname should start with slash and not contain any domain or query string.',
      path: [ 'redirects', 0, 'from' ],
      type: 'any.custom',
      context: {
        error: Error
            at C:\WS-Bender\PRODUCT-DOCS\node_modules\@docusaurus\utils-validation\lib\validationSchemas.js:66:15
            at Object.validate (C:\WS-Bender\PRODUCT-DOCS\node_modules\joi\lib\types\any.js:47:28)
            at internals.rules (C:\WS-Bender\PRODUCT-DOCS\node_modules\joi\lib\validator.js:494:33)
            at exports.validate (C:\WS-Bender\PRODUCT-DOCS\node_modules\joi\lib\validator.js:450:22)
            at internals.Base.$_validate (C:\WS-Bender\PRODUCT-DOCS\node_modules\joi\lib\base.js:774:26)
            at Object.validate (C:\WS-Bender\PRODUCT-DOCS\node_modules\joi\lib\types\alternatives.js:115:44)
            at exports.validate (C:\WS-Bender\PRODUCT-DOCS\node_modules\joi\lib\validator.js:425:26)
            at internals.Base.$_validate (C:\WS-Bender\PRODUCT-DOCS\node_modules\joi\lib\base.js:774:26)
            at Object.validate (C:\WS-Bender\PRODUCT-DOCS\node_modules\joi\lib\types\keys.js:108:45)
            at exports.validate (C:\WS-Bender\PRODUCT-DOCS\node_modules\joi\lib\validator.js:425:26),
        label: 'redirects[0].from',
        value: '/Load-Management/DLM/#hierarchial-dlm',
        key: 'from'
      }
    }
  ]
}
[INFO] Docusaurus version: 3.7.0
Node version: v21.5.0
error Command failed with exit code 1.

Reproducible demo

No response

Steps to reproduce

set redirects that have a hash fragment, e.g.,

/**
 * Docusaurus redirect rules for @docusaurus/plugin-client-redirects
 * Format: { from: string | string[], to: string }
 */

module.exports = [
    {
        from: '/Load-Management/DLM/#hierarchial-dlm',
        to: '/Load-Management/DLM/dlm-hierarchical',
    },
    {
        from: '/Load-Management/DLM/#solar-dlm',
        to: '/Load-Management/DLM/dlm-solar',
    },
];

Expected behavior

Working redirects.

Actual behavior

Validation error.

Your environment

• Docusaurus version used: 3.7.0

Self-service

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

[slorber]

Based on #9171, we only support redirecting to hash/querystring URLs, not from.

It's technically not possible to do that with our client redirect plugin, and we don't plan to implement that.

The client redirect plugin is a best effort implementation, and server-side redirects are always a better option. Redirection from one anchor in an existing content page is not a problem this plugin aims to solve.

Since you try to redirect from existing content pages, this means each content plugin has to implement this feature, and it's out of the scope of the client-redirect plugin which only emits new lightweight HTML redirect files.