fix: UriTemplate expansion reserved ("+") and fragment("#") should not encode already percent encoded parts

[alexander-asenov]

Currently the UriTemplate::expand method re-encodes already percent encoded triplets when using reserved("+") and fragment ("#") expansions, which should not be the case according to the RFC 6570.

The fix adds a new Encoder(PercentEncodedEscaper) that escapes already percent encoded parts of the input. It takes in the constructor another Escaper, allowing extensions of already existing Escapers, without changing/breaking any existing implementations.

• Make sure to open an issue as a bug/issue before writing your code! That way we can discuss the change, evaluate designs, and agree on the general idea
• Ensure the tests and linter pass
• Code coverage does not decrease (if any source code was changed)
• Appropriate docs were updated (if necessary)

Fixes #2107 ☕️

[cHengstler]

Hi @suztomo,

since you've reviewed our previous contribution.
Would it be possible to consider this contribution?

[suztomo]

@ldetmer maintains this repository these days.

[alexander-asenov]

Hi @ldetmer,
would you be able to take a look at this PR when you get a chance?

It aims to improve the library’s compliance with RFC 6570.
We’d love to contribute towards making it more compliant.

Let me know if there’s anything I should adjust or clarify before it can be considered.

Thanks a lot!
Alex

[alexander-asenov]

Hi @ldetmer,

Just wanted to follow up on the RFC 6570 compliance.

I know you're probably busy, so no rush at all! I just wanted to make sure it didn't get lost in the shuffle. If you need any additional context or have questions about the changes, I'm happy to provide more details. As I mentioned before we'd love to contribute towards making the library more compliant with the RFC.

Also, if there are any preliminary concerns you'd like me to address first, just let me know.

Thanks again for your time!
Alex

[diegomarquezp]

LGTM in general, given the following observations I'll leave here for other reviewers:

• new behavior indeed does not affect existing one
• confirmed compliance with the specification

However, support for {#var} and {+var} belong to level 2 templates, while we state we support "Level 1 templates and Level 4 composite templates" in

google-http-java-client/google-http-client/src/main/java/com/google/api/client/http/UriTemplate.java

Line 32 in 5d0689a

* <p>This Class supports Level 1 templates and all Level 4 composite templates as described in: <a

Would you mind clarifying this in that comment? Also, it could be useful to update #2107 as a feature request to support Level 2 templates.