fix(transport-commons): Allow case insensitive route lookups

[daffl]

This pull request allows case insensitive route lookups by setting app.routes.caseSensitive = false.

Closes #3330

[jeffreythomasprice]

Is it intended that when case-insensitive mode is on, all path parameters are to be lower cased as well? I suspect that it is not, given the check for the : prefix in the new code.

The behavior I see is that incoming path parameters are lower cased before they make it to our code. Our path parameters happen to be case sensitive, although the rest of the path is not. (Now that I'm seeing this, that's maybe a strange design decision we should revisit...)

I have a service like:

app.use('/foo/:bar/:baz')

The new code in packages/transport-commons/src/routing/router.ts does this:

getPath(path: string) {
  return stripSlashes(path).split('/')
  const result = stripSlashes(path).split('/')

  if (!this.caseSensitive) {
    return result.map((p) => (p.startsWith(':') ? p : p.toLowerCase()))
  }

  return result
}

If I invoke this endpoint with:

/foo/Something/SomethingElse

result will then be:

['foo', 'Something', 'SomethingElse']

None of those elements starts with :, so they will all get lowered.

[daffl]

Ah, the parameter name will be properly cased but not the value. That should indeed not be the case. The nodes themselves probably need to check it so this should be a follow-up issue to fix.