feat(config): allow configuration of the base_path (#2864)

Author: tusharmath

README.md

@@ -558,6 +558,7 @@ System-level environment variables (usually set automatically):
 
 ```bash
 # .env
+FORGE_CONFIG=/custom/config/dir        # Base directory for all Forge config files (default: ~/forge)
 FORGE_MAX_SEARCH_RESULT_BYTES=10240   # Maximum bytes for search results (default: 10240 - 10 KB)
 FORGE_HISTORY_FILE=/path/to/history    # Custom path for Forge history file (default: uses system default location)
 FORGE_BANNER="Your custom banner text" # Custom banner text to display on startup (default: Forge ASCII art)

crates/forge_app/src/orch_spec/orch_setup.rs

@@ -56,7 +56,6 @@ impl Default for TestContext {
             attachments: Default::default(),
             env: Environment {
                 os: "MacOS".to_string(),
-                pid: 1234,
                 cwd: PathBuf::from("/Users/tushar"),
                 home: Some(PathBuf::from("/Users/tushar")),
                 shell: "bash".to_string(),

crates/forge_config/src/reader.rs

@@ -49,8 +49,14 @@ impl ConfigReader {
         Self::base_path().join(".forge.toml")
     }
 
-    /// Returns the base directory for all Forge config files (`~/forge`).
+    /// Returns the base directory for all Forge config files.
+    ///
+    /// If the `FORGE_CONFIG` environment variable is set, its value is used
+    /// directly as the base path. Otherwise defaults to `~/forge`.
     pub fn base_path() -> PathBuf {
+        if let Ok(path) = std::env::var("FORGE_CONFIG") {
+            return PathBuf::from(path);
+        }
         dirs::home_dir().unwrap_or(PathBuf::from(".")).join("forge")
     }
 
@@ -164,6 +170,21 @@ mod tests {
         }
     }
 
+    #[test]
+    fn test_base_path_uses_forge_config_env_var() {
+        let _guard = EnvGuard::set(&[("FORGE_CONFIG", "/custom/forge/dir")]);
+        let actual = ConfigReader::base_path();
+        let expected = PathBuf::from("/custom/forge/dir");
+        assert_eq!(actual, expected);
+    }
+
+    #[test]
+    fn test_base_path_falls_back_to_home_dir_when_env_var_absent() {
+        let actual = ConfigReader::base_path();
+        // Without FORGE_CONFIG set the path must end with "forge"
+        assert_eq!(actual.file_name().unwrap(), "forge");
+    }
+
     #[test]
     fn test_read_parses_without_error() {
         let actual = ConfigReader::default().read_defaults().build();

crates/forge_domain/src/env.rs

@@ -47,8 +47,8 @@ const VERSION: &str = match option_env!("APP_VERSION") {
 /// Represents the minimal runtime environment in which the application is
 /// running.
 ///
-/// Contains only the six fields that cannot be sourced from [`ForgeConfig`]:
-/// `os`, `pid`, `cwd`, `home`, `shell`, and `base_path`. All configuration
+/// Contains only the five fields that cannot be sourced from [`ForgeConfig`]:
+/// `os`, `cwd`, `home`, `shell`, and `base_path`. All configuration
 /// values previously carried here are now accessed through
 /// `EnvironmentInfra::get_config()`.
 #[derive(Debug, Setters, Clone, PartialEq, Serialize, Deserialize, fake::Dummy)]
@@ -57,8 +57,6 @@ const VERSION: &str = match option_env!("APP_VERSION") {
 pub struct Environment {
     /// The operating system of the environment.
     pub os: String,
-    /// The process ID of the current process.
-    pub pid: u32,
     /// The current working directory.
     pub cwd: PathBuf,
     /// The home directory.

crates/forge_infra/src/env.rs

@@ -9,24 +9,20 @@ use tracing::debug;
 
 /// Builds a [`forge_domain::Environment`] from runtime context only.
 ///
-/// Only the six fields that cannot be sourced from [`ForgeConfig`] are set
-/// here: `os`, `pid`, `cwd`, `home`, `shell`, and `base_path`. All
-/// configuration values are now accessed through
-/// `EnvironmentInfra::get_config()`.
+/// Only the five fields that cannot be sourced from [`ForgeConfig`] are set
+/// here: `os`, `cwd`, `home`, `shell`, and `base_path`. All configuration
+/// values are now accessed through `EnvironmentInfra::get_config()`.
 pub fn to_environment(cwd: PathBuf) -> Environment {
     Environment {
         os: std::env::consts::OS.to_string(),
-        pid: std::process::id(),
         cwd,
         home: dirs::home_dir(),
         shell: if cfg!(target_os = "windows") {
             std::env::var("COMSPEC").unwrap_or_else(|_| "cmd.exe".to_string())
         } else {
             std::env::var("SHELL").unwrap_or_else(|_| "/bin/sh".to_string())
         },
-        base_path: dirs::home_dir()
-            .map(|h| h.join("forge"))
-            .unwrap_or_else(|| PathBuf::from(".").join("forge")),
+        base_path: ConfigReader::base_path(),
     }
 }
 
@@ -172,19 +168,65 @@ impl EnvironmentInfra for ForgeEnvironmentInfra {
 #[cfg(test)]
 mod tests {
     use std::path::PathBuf;
+    use std::sync::{Mutex, MutexGuard};
 
     use forge_config::ForgeConfig;
     use pretty_assertions::assert_eq;
 
     use super::*;
 
+    /// Serializes tests that mutate environment variables to prevent races.
+    static ENV_MUTEX: Mutex<()> = Mutex::new(());
+
+    /// Holds env vars set for a test's duration and removes them on drop,
+    /// while holding [`ENV_MUTEX`].
+    struct EnvGuard {
+        keys: Vec<&'static str>,
+        _lock: MutexGuard<'static, ()>,
+    }
+
+    impl EnvGuard {
+        #[must_use]
+        fn set(pairs: &[(&'static str, &str)]) -> Self {
+            let lock = ENV_MUTEX.lock().unwrap_or_else(|e| e.into_inner());
+            let keys = pairs.iter().map(|(k, _)| *k).collect();
+            for (key, value) in pairs {
+                unsafe { std::env::set_var(key, value) };
+            }
+            Self { keys, _lock: lock }
+        }
+    }
+
+    impl Drop for EnvGuard {
+        fn drop(&mut self) {
+            for key in &self.keys {
+                unsafe { std::env::remove_var(key) };
+            }
+        }
+    }
+
     #[test]
     fn test_to_environment_sets_cwd() {
         let fixture_cwd = PathBuf::from("/test/cwd");
         let actual = to_environment(fixture_cwd.clone());
         assert_eq!(actual.cwd, fixture_cwd);
     }
 
+    #[test]
+    fn test_to_environment_uses_forge_config_env_var() {
+        let _guard = EnvGuard::set(&[("FORGE_CONFIG", "/custom/config/dir")]);
+        let actual = to_environment(PathBuf::from("/any/cwd"));
+        let expected = PathBuf::from("/custom/config/dir");
+        assert_eq!(actual.base_path, expected);
+    }
+
+    #[test]
+    fn test_to_environment_falls_back_to_home_dir_when_env_var_absent() {
+        let actual = to_environment(PathBuf::from("/any/cwd"));
+        // Without FORGE_CONFIG the base_path must end with "forge"
+        assert_eq!(actual.base_path.file_name().unwrap(), "forge");
+    }
+
     #[test]
     fn test_apply_config_op_set_provider() {
         use forge_domain::ProviderId;

crates/forge_services/src/app_config.rs

@@ -267,7 +267,6 @@ mod tests {
         fn get_environment(&self) -> Environment {
             Environment {
                 os: "test".to_string(),
-                pid: 0,
                 cwd: PathBuf::new(),
                 home: None,
                 shell: "bash".to_string(),