refactor: extract config discovery into DiscoveredProjectConfig

Move config file discovery logic from `ProjectConfig` into a dedicated
`DiscoveredProjectConfig` struct that preserves the config file path.
This removes the side-effect of `set_current_dir()` during discovery
and instead exposes `config_dir()` for callers to resolve paths
relative to the config file location.

Also stop merging `working_directory` from config in the merger since
it needs path resolution relative to the config file directory, which
the merger doesn't have access to.

Author: GuillaumeLagrange

src/cli/mod.rs

@@ -15,7 +15,7 @@ use crate::{
     config::CodSpeedConfig,
     local_logger::{CODSPEED_U8_COLOR_CODE, init_local_logger},
     prelude::*,
-    project_config::ProjectConfig,
+    project_config::DiscoveredProjectConfig,
 };
 use clap::{
     Parser, Subcommand,
@@ -97,9 +97,11 @@ pub async fn run() -> Result<()> {
         CodSpeedConfig::load_with_override(cli.config_name.as_deref(), cli.oauth_token.as_deref())?;
     let api_client = CodSpeedAPIClient::try_from((&cli, &codspeed_config))?;
 
-    // Discover project configuration file (this may change the working directory)
-    let project_config =
-        ProjectConfig::discover_and_load(cli.config.as_deref(), &std::env::current_dir()?)?;
+    // Discover project configuration file
+    let discovered_config = DiscoveredProjectConfig::discover_and_load(
+        cli.config.as_deref(),
+        &std::env::current_dir()?,
+    )?;
 
     // In the context of the CI, it is likely that a ~ made its way here without being expanded by the shell
     let setup_cache_dir = cli
@@ -121,7 +123,7 @@ pub async fn run() -> Result<()> {
                 *args,
                 &api_client,
                 &codspeed_config,
-                project_config.as_ref(),
+                discovered_config.as_ref(),
                 setup_cache_dir,
             )
             .await?
@@ -131,7 +133,7 @@ pub async fn run() -> Result<()> {
                 *args,
                 &api_client,
                 &codspeed_config,
-                project_config.as_ref(),
+                discovered_config.as_ref().map(|d| &d.config),
                 setup_cache_dir,
             )
             .await?

src/cli/run/mod.rs

@@ -5,8 +5,8 @@ use crate::executor;
 use crate::executor::config::{self, OrchestratorConfig, RepositoryOverride};
 use crate::instruments::Instruments;
 use crate::prelude::*;
-use crate::project_config::ProjectConfig;
 use crate::project_config::merger::ConfigMerger;
+use crate::project_config::{DiscoveredProjectConfig, ProjectConfig};
 use crate::run_environment::interfaces::RepositoryProvider;
 use crate::upload::poll_results::PollResultsOptions;
 use clap::{Args, ValueEnum};
@@ -152,13 +152,13 @@ pub async fn run(
     args: RunArgs,
     api_client: &CodSpeedAPIClient,
     codspeed_config: &CodSpeedConfig,
-    project_config: Option<&ProjectConfig>,
+    discovered_config: Option<&DiscoveredProjectConfig>,
     setup_cache_dir: Option<&Path>,
 ) -> Result<()> {
     let output_json = args.message_format == Some(MessageFormat::Json);
+    let project_config = discovered_config.map(|d| &d.config);
 
     let args = args.merge_with_project_config(project_config);
-
     let run_target = if args.command.is_empty() {
         // No command provided - check for targets in project config
         let targets = project_config

src/executor/tests.rs

@@ -370,7 +370,6 @@ fi
         // Unset GITHUB_ACTIONS to force LocalProvider which supports repository_override
         temp_env::async_with_vars(&[("GITHUB_ACTIONS", None::<&str>)], async {
             let config = walltime_config(&wrapped_command, true);
-            dbg!(&config);
             let (execution_context, _temp_dir) = create_test_setup(config).await;
             executor.run(&execution_context, &None).await.unwrap();
         })

src/project_config/discover.rs

@@ -0,0 +1,102 @@
+use crate::prelude::*;
+use std::path::{Path, PathBuf};
+
+use super::ProjectConfig;
+
+/// Config file names in priority order
+const CONFIG_FILENAMES: &[&str] = &[
+    "codspeed.yaml",
+    "codspeed.yml",
+    ".codspeed.yaml",
+    ".codspeed.yml",
+];
+
+/// A project configuration paired with the path it was loaded from.
+#[derive(Debug)]
+#[allow(dead_code)]
+pub struct DiscoveredProjectConfig {
+    pub config: ProjectConfig,
+    pub path: PathBuf,
+}
+
+impl DiscoveredProjectConfig {
+    /// Discover and load project configuration file
+    ///
+    /// # Search Strategy
+    /// 1. If `config_path_override` is provided, load from that path only (error if not found)
+    /// 2. Otherwise, search for config files in current directory and upward to git root
+    /// 3. Try filenames in priority order: codspeed.yaml, codspeed.yml, .codspeed.yaml, .codspeed.yml
+    pub fn discover_and_load(
+        config_path_override: Option<&Path>,
+        current_dir: &Path,
+    ) -> Result<Option<DiscoveredProjectConfig>> {
+        // Case 1: Explicit --config path provided
+        if let Some(config_path) = config_path_override {
+            let config = ProjectConfig::load_from_path(config_path)
+                .with_context(|| format!("Failed to load config from {}", config_path.display()))?;
+
+            return Ok(Some(DiscoveredProjectConfig {
+                config,
+                path: config_path.to_path_buf(),
+            }));
+        }
+
+        // Case 2: Search for config files
+        let search_dirs = Self::get_search_directories(current_dir)?;
+
+        for dir in search_dirs {
+            for filename in CONFIG_FILENAMES {
+                let candidate_path = dir.join(filename);
+                if candidate_path.exists() {
+                    debug!("Found config file at {}", candidate_path.display());
+                    let config = ProjectConfig::load_from_path(&candidate_path)?;
+
+                    return Ok(Some(DiscoveredProjectConfig {
+                        config,
+                        path: candidate_path,
+                    }));
+                }
+            }
+        }
+
+        // No config found - this is OK
+        Ok(None)
+    }
+
+    /// Returns the directory containing the config file.
+    #[allow(dead_code)]
+    pub fn config_dir(&self) -> Option<PathBuf> {
+        let canonical_path = self
+            .path
+            .canonicalize()
+            .unwrap_or_else(|_| self.path.clone());
+        canonical_path.parent().map(|p| p.to_path_buf())
+    }
+
+    /// Get list of directories to search for config files
+    ///
+    /// Returns directories from current_dir upward to git root (if in a git repo)
+    fn get_search_directories(current_dir: &Path) -> Result<Vec<PathBuf>> {
+        let mut dirs = vec![current_dir.to_path_buf()];
+
+        // Try to find git repository root
+        if let Some(git_root) = crate::cli::run::helpers::find_repository_root(current_dir) {
+            // Add parent directories up to git root
+            let mut dir = current_dir.to_path_buf();
+            while let Some(parent) = dir.parent() {
+                if parent == git_root {
+                    if !dirs.contains(&git_root) {
+                        dirs.push(git_root.clone());
+                    }
+                    break;
+                }
+                if !dirs.contains(&parent.to_path_buf()) {
+                    dirs.push(parent.to_path_buf());
+                }
+                dir = parent.to_path_buf();
+            }
+        }
+
+        Ok(dirs)
+    }
+}

src/project_config/merger.rs

@@ -41,18 +41,12 @@ impl ConfigMerger {
     /// Note: Some fields like upload_url, token, repository are CLI-only and not in config.
     pub fn merge_shared_args(
         cli: &ExecAndRunSharedArgs,
-        config_opts: Option<&ProjectOptions>,
+        _config_opts: Option<&ProjectOptions>,
     ) -> ExecAndRunSharedArgs {
-        let mut merged = cli.clone();
-
-        // Merge working_directory if not set via CLI
-        if merged.working_directory.is_none() {
-            if let Some(opts) = config_opts {
-                merged.working_directory = opts.working_directory.clone();
-            }
-        }
-
-        merged
+        // Note: working_directory is NOT merged here because config paths need to be
+        // resolved relative to the config file directory. This resolution is handled
+        // by the caller (e.g., `codspeed run`) which has access to the config file path.
+        cli.clone()
     }
 
     /// Helper to merge Option values with precedence: CLI > config > None
@@ -67,6 +61,29 @@ mod tests {
     use crate::cli::PerfRunArgs;
     use crate::runner_mode::RunnerMode;
 
+    fn make_cli(working_directory: Option<&str>) -> ExecAndRunSharedArgs {
+        ExecAndRunSharedArgs {
+            upload_url: None,
+            token: None,
+            repository: None,
+            provider: None,
+            working_directory: working_directory.map(|s| s.to_string()),
+            mode: vec![RunnerMode::Walltime],
+            simulation_tool: None,
+            profile_folder: None,
+            skip_upload: false,
+            skip_run: false,
+            skip_setup: false,
+            allow_empty: false,
+            go_runner_version: None,
+            show_full_output: false,
+            perf_run_args: PerfRunArgs {
+                enable_perf: true,
+                perf_unwinding_mode: None,
+            },
+        }
+    }
+
     #[test]
     fn test_merge_walltime_all_from_cli() {
         let cli = WalltimeExecutionArgs {
@@ -146,27 +163,7 @@ mod tests {
 
     #[test]
     fn test_merge_shared_args_working_directory_from_cli() {
-        let cli = ExecAndRunSharedArgs {
-            upload_url: None,
-            token: None,
-            repository: None,
-            provider: None,
-            working_directory: Some("./cli-dir".to_string()),
-            mode: vec![RunnerMode::Walltime],
-            simulation_tool: None,
-            profile_folder: None,
-            skip_upload: false,
-            skip_run: false,
-            skip_setup: false,
-            allow_empty: false,
-            go_runner_version: None,
-            show_full_output: false,
-            perf_run_args: PerfRunArgs {
-                enable_perf: true,
-                perf_unwinding_mode: None,
-            },
-        };
-
+        let cli = make_cli(Some("./cli-dir"));
         let config = ProjectOptions {
             walltime: None,
             working_directory: Some("./config-dir".to_string()),
@@ -179,69 +176,30 @@ mod tests {
     }
 
     #[test]
-    fn test_merge_shared_args_working_directory_from_config() {
-        let cli = ExecAndRunSharedArgs {
-            upload_url: None,
-            token: None,
-            repository: None,
-            provider: None,
-            working_directory: None,
-            mode: vec![RunnerMode::Walltime],
-            simulation_tool: None,
-            profile_folder: None,
-            skip_upload: false,
-            skip_run: false,
-            skip_setup: false,
-            allow_empty: false,
-            go_runner_version: None,
-            show_full_output: false,
-            perf_run_args: PerfRunArgs {
-                enable_perf: true,
-                perf_unwinding_mode: None,
-            },
-        };
-
+    fn test_merge_shared_args_working_directory_not_merged_from_config() {
+        let cli = make_cli(None);
         let config = ProjectOptions {
             walltime: None,
             working_directory: Some("./config-dir".to_string()),
         };
 
         let merged = ConfigMerger::merge_shared_args(&cli, Some(&config));
 
-        // Config working_directory should be used
-        assert_eq!(merged.working_directory, Some("./config-dir".to_string()));
+        // Config working_directory is NOT merged — resolution is handled by the caller
+        // relative to the config file directory.
+        assert_eq!(merged.working_directory, None);
         // Mode stays as CLI value
         assert_eq!(merged.mode, vec![RunnerMode::Walltime]);
     }
 
     #[test]
     fn test_merge_shared_args_no_config() {
-        let cli = ExecAndRunSharedArgs {
-            upload_url: None,
-            token: None,
-            repository: None,
-            provider: None,
-            working_directory: Some("./dir".to_string()),
-            mode: vec![RunnerMode::Simulation],
-            simulation_tool: None,
-            profile_folder: None,
-            skip_upload: false,
-            skip_run: false,
-            skip_setup: false,
-            allow_empty: false,
-            go_runner_version: None,
-            show_full_output: false,
-            perf_run_args: PerfRunArgs {
-                enable_perf: false,
-                perf_unwinding_mode: None,
-            },
-        };
+        let cli = make_cli(Some("./dir"));
 
         let merged = ConfigMerger::merge_shared_args(&cli, None);
 
         // Should be identical to CLI
         assert_eq!(merged.working_directory, Some("./dir".to_string()));
-        assert_eq!(merged.mode, vec![RunnerMode::Simulation]);
     }
 
     #[test]