fix: make config file saves atomic

Cargo.toml

@@ -44,6 +44,7 @@ tracing-subscriber = { version = "0.3", features = ["env-filter"] }
 dialoguer = "0.12"
 console = "0.15"
 ctrlc = "3"
+uuid = { version = "1.19.0", features = ["v4"] }
 
 [dev-dependencies]
 tempfile = "3"

src/cli/install.rs

@@ -1,3 +1,4 @@
+use crate::utils::write_atomic;
 use anyhow::{Context, Result};
 use console::style;
 use std::fs;
@@ -61,7 +62,7 @@ pub fn install_claude_code() -> Result<()> {
     if !content.contains("vgrep") {
         content.push_str("\n\n");
         content.push_str(VGREP_SKILL.trim());
-        fs::write(&instructions_path, content)?;
+        write_atomic(&instructions_path, content)?;
         println!(
             "  {} Added vgrep skill to Claude Code",
             style("[+]").green()
@@ -101,7 +102,7 @@ pub fn uninstall_claude_code() -> Result<()> {
         let updated = content
             .replace(VGREP_SKILL.trim(), "")
             .replace("\n\n\n", "\n\n");
-        fs::write(&instructions_path, updated.trim())?;
+        write_atomic(&instructions_path, updated.trim())?;
         println!("  {} Removed vgrep from Claude Code", style("[-]").green());
     } else {
         println!(
@@ -144,7 +145,7 @@ Usage:
 })"#;
 
     let tool_path = tool_dir.join("vgrep.ts");
-    fs::write(&tool_path, tool_content.trim())?;
+    write_atomic(&tool_path, tool_content.trim())?;
     println!("  {} Created vgrep tool", style("[+]").green());
 
     // Update opencode.json
@@ -169,7 +170,7 @@ Usage:
         "enabled": true
     });
 
-    fs::write(&config_path, serde_json::to_string_pretty(&config)?)?;
+    write_atomic(&config_path, serde_json::to_string_pretty(&config)?)?;
     println!("  {} Updated OpenCode config", style("[+]").green());
 
     println!();
@@ -204,7 +205,7 @@ pub fn uninstall_opencode() -> Result<()> {
                     obj.remove("vgrep");
                 }
             }
-            fs::write(&config_path, serde_json::to_string_pretty(&config)?)?;
+            write_atomic(&config_path, serde_json::to_string_pretty(&config)?)?;
             println!("  {} Updated OpenCode config", style("[-]").green());
         }
     }
@@ -228,7 +229,7 @@ pub fn install_codex() -> Result<()> {
     if !content.contains("vgrep") {
         content.push_str("\n\n");
         content.push_str(VGREP_SKILL.trim());
-        fs::write(&agents_path, content)?;
+        write_atomic(&agents_path, content)?;
         println!("  {} Added vgrep skill to Codex", style("[+]").green());
     } else {
         println!(
@@ -257,7 +258,7 @@ pub fn uninstall_codex() -> Result<()> {
         if updated.trim().is_empty() {
             fs::remove_file(&agents_path)?;
         } else {
-            fs::write(&agents_path, updated.trim())?;
+            write_atomic(&agents_path, updated.trim())?;
         }
         println!("  {} Removed vgrep from Codex", style("[-]").green());
     }
@@ -284,7 +285,7 @@ pub fn install_droid() -> Result<()> {
     fs::create_dir_all(&skills_dir)?;
 
     let skill_content = VGREP_SKILL.trim();
-    fs::write(skills_dir.join("SKILL.md"), skill_content)?;
+    write_atomic(skills_dir.join("SKILL.md"), skill_content)?;
     println!("  {} Created vgrep skill", style("[+]").green());
 
     // Create hooks
@@ -344,8 +345,8 @@ if __name__ == "__main__":
     main()
 "#;
 
-    fs::write(hooks_dir.join("vgrep_watch.py"), watch_hook)?;
-    fs::write(hooks_dir.join("vgrep_watch_kill.py"), kill_hook)?;
+    write_atomic(hooks_dir.join("vgrep_watch.py"), watch_hook)?;
+    write_atomic(hooks_dir.join("vgrep_watch_kill.py"), kill_hook)?;
     println!("  {} Created vgrep hooks", style("[+]").green());
 
     // Update settings.json
@@ -412,7 +413,7 @@ if __name__ == "__main__":
     }
 
     settings["hooks"] = serde_json::Value::Object(hooks);
-    fs::write(&settings_path, serde_json::to_string_pretty(&settings)?)?;
+    write_atomic(&settings_path, serde_json::to_string_pretty(&settings)?)?;
     println!("  {} Updated Factory Droid settings", style("[+]").green());
 
     println!();
@@ -461,7 +462,7 @@ pub fn uninstall_droid() -> Result<()> {
                         obj.retain(|_, v| v.as_array().map(|a| !a.is_empty()).unwrap_or(true));
                     }
                 }
-                fs::write(&settings_path, serde_json::to_string_pretty(&settings)?)?;
+                write_atomic(&settings_path, serde_json::to_string_pretty(&settings)?)?;
             }
         }
         println!("  {} Updated Factory Droid settings", style("[-]").green());

src/config.rs

@@ -224,7 +224,7 @@ impl Config {
         std::fs::create_dir_all(&config_dir)?;
         let config_path = config_dir.join(CONFIG_FILE);
         let content = serde_json::to_string_pretty(self)?;
-        std::fs::write(&config_path, content)?;
+        crate::utils::write_atomic(&config_path, content)?;
         Ok(())
     }
 

src/lib.rs

@@ -18,6 +18,7 @@ pub mod core;
 pub mod server;
 pub mod ui;
 pub mod watcher;
+pub mod utils;
 
 pub use config::Config;
 pub use core::{Database, EmbeddingEngine, Indexer, SearchEngine, ServerIndexer};

src/utils.rs

@@ -0,0 +1,40 @@
+use std::path::Path;
+use std::fs;
+use anyhow::Result;
+
+/// Write content to a file atomically by writing to a temp file and renaming it
+pub fn write_atomic<P: AsRef<Path>, C: AsRef<[u8]>>(path: P, content: C) -> Result<()> {
+    let path = path.as_ref();
+    let dir = path.parent().unwrap_or_else(|| Path::new("."));
+
+    // Create directory if it doesn't exist
+    fs::create_dir_all(dir)?;
+
+    // Create a temporary file in the same directory to ensure it's on the same filesystem
+    // We use a simple strategy: filename.tmp.uuid
+    let tmp_file_name = format!("{}.tmp.{}", 
+        path.file_name().unwrap_or_default().to_string_lossy(),
+        uuid::Uuid::new_v4()
+    );
+    let tmp_path = dir.join(tmp_file_name);
+
+    // Write content to temp file
+    match fs::write(&tmp_path, content) {
+        Ok(_) => {
+            // Rename temp file to destination
+            match fs::rename(&tmp_path, path) {
+                Ok(_) => Ok(()),
+                Err(e) => {
+                    // Try to clean up temp file if rename fails
+                    let _ = fs::remove_file(&tmp_path);
+                    Err(anyhow::anyhow!("Failed to rename temp file to destination: {}", e))
+                }
+            }
+        },
+        Err(e) => {
+            // Try to clean up temp file if write fails
+            let _ = fs::remove_file(&tmp_path);
+            Err(anyhow::anyhow!("Failed to write to temp file: {}", e))
+        }
+    }
+}