fix: go module with replace

[not-matthias]

Fixes #31

[codspeed-hq]

CodSpeed Performance Report

Merging #32 will not alter performance

_{Comparing cod-1666-codspeed-go-is-unable-to-run-benchmarks-on-go-modules-with (1679125) with main (5a7740c)}

Summary

✅ 24 untouched
🆕 6 new

Benchmarks breakdown

	Benchmark	BASE	HEAD	Change
🆕	bench_collect_results[10000000]	N/A	21.5 s	N/A
🆕	bench_collect_results[1000000]	N/A	1.8 s	N/A
🆕	bench_collect_results[100000]	N/A	182 ms	N/A
🆕	bench_collect_results[5000000]	N/A	10.9 s	N/A
🆕	bench_collect_results[500000]	N/A	916.5 ms	N/A
🆕	bench_go_runner	N/A	38.8 s	N/A

[Copilot]

Pull Request Overview

This PR fixes support for Go modules with replace directives (fixes #31) and adds a dry-run mode for benchmarking. The key changes involve copying the entire git repository instead of just the module directory to properly support local replace directives, handling symlinks, and adding build-only mode for performance testing.

• Implements dry-run CLI flag that builds benchmarks without executing them
• Changes build process to copy entire git repository instead of just module directory to support replace directives
• Adds symlink handling in directory copying to follow directory symlinks
• Adds performance benchmarking infrastructure using divan/codspeed

Reviewed Changes

Copilot reviewed 17 out of 18 changed files in this pull request and generated 2 comments.

Show a summary per file

File	Description
go-runner/src/cli.rs	Adds dry-run flag parsing and documentation
go-runner/src/lib.rs	Implements dry-run mode to skip benchmark execution and result collection
go-runner/src/utils.rs	Adds symlink handling and makes git repo path function public
go-runner/src/builder/templater.rs	Changes to copy git root instead of module dir and calculates module paths relative to git root
go-runner/src/builder/patcher.rs	Adds graceful error handling for unparseable Go files and optimization to skip parsing when unnecessary
go-runner/src/builder/discovery.rs	Optimizes benchmark detection by checking for "func Benchmark" before parsing
go-runner/tests/pkg_arg.rs	Updates tests to include dry_run field
go-runner/testdata/projects/example-with-replace/*	Adds new test project demonstrating replace directive support
go-runner/benches/go_runner.rs	Adds performance benchmark for the go-runner itself
go-runner/Cargo.toml	Adds divan benchmarking dependency and configuration
.github/workflows/codspeed.yml	Adds CI workflow for running benchmarks

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[adriencaccia]

lgtm, waiting on @GuillaumeLagrange's review

[GuillaumeLagrange]

olgtm, next review should be almost instant

[GuillaumeLagrange]

lgtm