Convert gix-revision to use gix-error and update gix API

[Copilot]

Removes thiserror from gix-revision and converts to gix-error, following the pattern established in gix-date. Additionally updates the gix crate's API to return gix::Error from revision parsing functions.

Changes

• spec::parse::Error: Now uses gix_error::ParseError instead of custom enum with 15+ variants
• describe::Error and merge_base::Error: Converted to simple error types wrapping string messages
• Error creation sites: All 50+ error construction sites updated to use Error::new() and Error::new_with_input()
• Test assertions: 112 tests updated to check error messages/input instead of enum variant matching
• gix API changes:
  • Spec::from_bstr() now returns gix::Error instead of revision::spec::parse::Error
  • Repository::rev_parse() now returns gix::Error
  • Parse errors are wrapped with gix_error::Message::new(format!(...)) for inline error messages

Before/After

// Before (gix-revision)
#[derive(Debug, thiserror::Error)]
pub enum Error {
    #[error("'~' needs to follow an anchor, like '@~'.")]
    MissingTildeAnchor,
    #[error("Could not parse time {:?} for revlog lookup.", .input)]
    Time { input: BString, source: Option<Box<gix_date::Error>> },
    // ... 13 more variants
}

// After (gix-revision)
pub use gix_error::ParseError as Error;

// Usage
Err(Error::new("tilde needs to follow an anchor, like @~"))
Err(Error::new_with_input("could not parse time for reflog lookup", nav))

// Before (gix)
pub fn from_bstr(...) -> Result<Self, Error> // where Error is revision::spec::parse::Error

// After (gix)
pub fn from_bstr(...) -> Result<Self, crate::Error> // where Error is gix::Error

All tests passing.

---

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[Copilot]

Pull request overview

This PR converts gix-revision from using thiserror to gix-error, following the pattern established in gix-date. The conversion simplifies error handling by replacing structured error enums with string-based error messages.

Changes:

• Replaced spec::parse::Error enum (15+ variants) with gix_error::ParseError type alias
• Converted describe::Error and merge_base::Error to simple wrapper types with string messages
• Updated all 50+ error construction sites to use Error::new() and Error::new_with_input()
• Modified 112 test assertions to check error messages/input using substring matching instead of enum variant matching

Reviewed changes

Copilot reviewed 12 out of 13 changed files in this pull request and generated no comments.

Show a summary per file

File	Description
gix-revision/Cargo.toml	Removed thiserror dependency
Cargo.lock	Updated to reflect removal of thiserror from gix-revision
gix-revision/src/spec/parse/mod.rs	Replaced Error enum with gix_error::ParseError type alias
gix-revision/src/spec/parse/function.rs	Updated all error construction sites to use Error::new() and Error::new_with_input()
gix-revision/src/merge_base/mod.rs	Introduced Simple(&'static str) error wrapper for static error messages
gix-revision/src/merge_base/function.rs	Updated error construction to use Simple wrapper with static strings
gix-revision/src/describe.rs	Introduced Simple(String) error wrapper for dynamic error messages (e.g., with commit hashes)
gix-revision/tests/revision/spec/parse/navigate/tilde_symbol.rs	Updated test assertions to check error message content
gix-revision/tests/revision/spec/parse/navigate/caret_symbol.rs	Updated test assertions to check error message content and input
gix-revision/tests/revision/spec/parse/kind.rs	Updated test assertions to check error message content
gix-revision/tests/revision/spec/parse/anchor/refnames.rs	Updated test assertions to check error message content and input
gix-revision/tests/revision/spec/parse/anchor/colon_symbol.rs	Updated test assertions to check error message content and input
gix-revision/tests/revision/spec/parse/anchor/at_symbol.rs	Updated test assertions to check error message content and input

[Byron]

@copilot let Spec::from_bstr() return gix::Error instead,
and copy the formatted error message from the previous error type inline via gix_error::Message::new(format!(…)).

[Copilot]

@copilot let Spec::from_bstr() return gix::Error instead,
and cop...

I've updated Spec::from_bstr() to return gix::Error and wrapped parse errors with gix_error::Message::new(format!(...)) to create inline error messages. Also updated Repository::rev_parse() to use the new error type.

Commit: daed5d3