The recent work done in #3697 uncovered a previously unknown bug where we do not match default browser behavior. By default, non-JS <form method="get"> will replace any existing search parameters in the URL, but our behavior has been to append (without first resetting the params) since #814.

Default browser behavior is shown in this code sandbox. You may have to open it in a new window and load it with some existing query params, and then submit the form. I.e., https://e26g6e.sse.codesandbox.io/?junk=value

This new Remix behavior also has the side effect of no longer including the ?index in the destination URL (even though it is included in the form action). This should have no impact since GET submissions run all relevant loaders.

// routes/parent/index.tsx
<Form>
  <input name="bar" value="2" />
  <button type="submit">Submit</button>
</Form>

• Current behavior after fix(remix-react): Preserve search string in form action when action prop is omitted #3697
  • User loads /parent?foo=1
  • Rendered HTML is <form action="/parent?index&foo=1">
  • User clicks submit
  • Browser URL navigates to /parent?index&foo=1&bar=2
  • Rendered HTML is now <form action="/parent?index&foo=1&bar=2">
• New behavior
  • User loads /parent?foo=1
  • Rendered HTML is <form action="/parent?index&foo=1">
  • User clicks submit
  • Browser URL navigates to /parent?bar=2
  • Rendered HTML is now <form action="/parent?index&bar=2">

Closes: #4044

• Docs
• Tests

Testing Strategy:

• Updated form-test integration tests