Rust: Add a type inference test case resembling PathBuf.canonicalize.

[geoffw0]

Add a type inference test case resembling what I think happens in real world calls to PathBuf.canonicalize, affecting the function of our rust/path-injection barriers flow states. My understanding is that the Deref trait on PathBuf makes it behave much like a pointer to / slice of a Path, and type inference fails to work through what I believe is an implicit dereference on line 2597 of the test.

The lack of support for the Deref trait is already a known problem, but I think it's good to have test coverage resembling real world patterns that matter to our analysis.

@hvitved

[Copilot]

Pull Request Overview

This PR adds a test case to demonstrate type inference limitations with the Deref trait in Rust, specifically testing a pattern resembling PathBuf.canonicalize() which is relevant to path injection analysis.

• Adds a simplified model of Path and PathBuf types with canonicalize method
• Implements Deref trait for PathBuf to demonstrate implicit dereference behavior
• Tests type inference through both direct method calls and calls via Deref trait

Reviewed Changes

Copilot reviewed 2 out of 2 changed files in this pull request and generated no comments.

File	Description
main.rs	Adds new path_buf module with test types and function demonstrating Deref trait limitations
type-inference.expected	Updates expected test output with new type inference results for the added test cases

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[hvitved]

My understanding is that the Deref trait on PathBuf makes it behave much like a pointer to / slice of a Path, and type inference fails to work through what I believe is an implicit dereference on line 2597 of the test.

Did you mean line 2601?

[geoffw0]

Did you mean line 2601?

Yes. :)