agent_engine/tools/

edit.rs

use super::{resolve_path_in, Tool, ToolContext};
use crate::{Result, RuntimeError};
use serde_json::{json, Value};

pub struct EditTool;

#[async_trait::async_trait]
impl Tool for EditTool {
    fn effect(&self) -> crate::tools::catalog::ToolEffect {
        crate::tools::catalog::ToolEffect::IdempotentWrite
    }

    fn concurrency_key(
        &self,
        validated_input: &serde_json::Value,
    ) -> Option<super::ConcurrencyKey> {
        Some(
            match super::util::canonical_path_key(validated_input["path"].as_str()?) {
                Some(key) => super::ConcurrencyKey::Key(key),
                None => super::ConcurrencyKey::Serialize,
            },
        )
    }

    fn origin(&self) -> crate::tools::ToolOrigin {
        crate::tools::ToolOrigin::Builtin
    }

    fn name(&self) -> &str {
        "edit"
    }

    fn description(&self) -> &str {
        "Make a surgical edit to a file by replacing an exact string match. The old_string must appear exactly once in the file. Provide enough surrounding context to make the match unique."
    }

    fn parameters(&self) -> Value {
        json!({
            "type": "object",
            "properties": {
                "path": {
                    "type": "string",
                    "description": "Path to the file to edit"
                },
                "old_string": {
                    "type": "string",
                    "description": "The exact text to find and replace. Must match exactly once in the file."
                },
                "new_string": {
                    "type": "string",
                    "description": "The replacement text"
                }
            },
            "required": ["path", "old_string", "new_string"]
        })
    }

    async fn execute(&self, params: Value, ctx: ToolContext) -> Result<String> {
        let raw_path = params["path"]
            .as_str()
            .ok_or_else(|| RuntimeError::Tool("Missing path parameter".to_string()))?;
        let old_string = params["old_string"]
            .as_str()
            .ok_or_else(|| RuntimeError::Tool("Missing old_string parameter".to_string()))?;
        let new_string = params["new_string"]
            .as_str()
            .ok_or_else(|| RuntimeError::Tool("Missing new_string parameter".to_string()))?;
        if let Some(orchestration) = &ctx.capabilities.orchestration {
            if matches!(
                orchestration.check_foreground_write(raw_path),
                agent_core::orchestration::ScopeDecision::ReconciliationRequired { .. }
            ) {
                return Err(RuntimeError::Tool(
                    "foreground edit overlaps an active worker scope".into(),
                ));
            }
        }

        let path = resolve_path_in(raw_path, ctx.capabilities.cwd.as_deref());

        let content = tokio::fs::read_to_string(&path).await.map_err(|e| {
            RuntimeError::Tool(format!("Failed to read file '{}': {}", path.display(), e))
        })?;

        let count = content.matches(old_string).count();

        if count == 0 {
            return Err(RuntimeError::Tool(format!(
                "old_string not found in '{}'. Make sure it matches exactly, including whitespace and indentation.",
                path.display()
            )));
        }

        if count > 1 {
            return Err(RuntimeError::Tool(format!(
                "old_string found {} times in '{}'. It must be unique — include more surrounding context.",
                count, path.display()
            )));
        }

        let new_content = content.replacen(old_string, new_string, 1);

        // Preserve original file permissions (executable bits, etc.)
        let original_perms = tokio::fs::metadata(&path)
            .await
            .map(|m| m.permissions())
            .ok();

        let tmp_path = super::util::unique_tmp_path(&path);
        tokio::fs::write(&tmp_path, &new_content)
            .await
            .map_err(|e| RuntimeError::Tool(format!("Failed to write file: {}", e)))?;

        // Restore original permissions on the temp file before rename
        if let Some(perms) = original_perms {
            let _ = tokio::fs::set_permissions(&tmp_path, perms).await;
        }

        tokio::fs::rename(&tmp_path, &path).await.map_err(|e| {
            let tmp = tmp_path.clone();
            tokio::spawn(async move {
                let _ = tokio::fs::remove_file(tmp).await;
            });
            RuntimeError::Tool(format!("Failed to finalize edit: {}", e))
        })?;

        let old_lines: Vec<&str> = old_string.lines().collect();
        let new_lines: Vec<&str> = new_string.lines().collect();
        Ok(format!(
            "Edited {} — replaced {} line(s) with {} line(s)",
            path.display(),
            old_lines.len(),
            new_lines.len()
        ))
    }
}
#[cfg(test)]
mod tests {
    use super::super::test_helpers::create_tool_context;
    use super::*;
    use crate::tools::Tool;
    use serde_json::json;

    #[test]
    fn test_edit_tool_schema() {
        let tool = EditTool;
        assert_eq!(tool.name(), "edit");
        assert!(!tool.description().is_empty());

        let params = tool.parameters();
        assert_eq!(params["type"], "object");
        assert!(params["properties"].is_object());
        assert!(params["required"].is_array());
    }

    #[tokio::test]
    async fn test_edit_tool_execution() {
        let temp_dir = std::env::temp_dir();
        let test_file = temp_dir.join("edit_tool_test.txt");

        // Create file with known content
        let initial_content = "Hello world\nThis is a test\nEnd of file";
        std::fs::write(&test_file, initial_content).unwrap();

        let tool = EditTool;

        // Test successful replacement
        let ctx = create_tool_context();
        let params = json!({
            "path": test_file.to_string_lossy(),
            "old_string": "This is a test",
            "new_string": "This is modified"
        });

        let result = tool.execute(params, ctx).await.unwrap();
        assert!(result.contains("Edited"));
        assert!(result.contains("replaced 1 line(s) with 1 line(s)"));

        let modified_content = std::fs::read_to_string(&test_file).unwrap();
        assert!(modified_content.contains("This is modified"));
        assert!(!modified_content.contains("This is a test"));

        // Test old_string not found
        let ctx = create_tool_context();
        let params = json!({
            "path": test_file.to_string_lossy(),
            "old_string": "nonexistent string",
            "new_string": "replacement"
        });

        let result = tool.execute(params, ctx).await;
        assert!(result.is_err());
        assert!(result
            .unwrap_err()
            .to_string()
            .contains("old_string not found"));

        // Test old_string found multiple times
        std::fs::write(&test_file, "test\ntest\nother").unwrap();
        let ctx = create_tool_context();
        let params = json!({
            "path": test_file.to_string_lossy(),
            "old_string": "test",
            "new_string": "replacement"
        });

        let result = tool.execute(params, ctx).await;
        assert!(result.is_err());
        let error_msg = result.unwrap_err().to_string();
        assert!(error_msg.contains("found 2 times"));
        assert!(error_msg.contains("must be unique"));

        // Cleanup
        let _ = std::fs::remove_file(&test_file);
    }

    #[tokio::test]
    async fn test_edit_tool_no_match() {
        let temp_dir = std::env::temp_dir();
        let test_file = temp_dir.join("test_edit_tool_no_match.txt");

        // Create file with known content
        let content = "some content\nmore content";
        std::fs::write(&test_file, content).unwrap();

        let tool = EditTool;
        let ctx = create_tool_context();

        let params = json!({
            "path": test_file.to_string_lossy(),
            "old_string": "this string does not exist",
            "new_string": "replacement"
        });

        let result = tool.execute(params, ctx).await;

        // Should return error about string not found
        assert!(result.is_err());
        let error = result.unwrap_err().to_string();
        assert!(error.contains("old_string not found"));

        // Cleanup
        let _ = std::fs::remove_file(&test_file);
    }

    // Regression: two files sharing a stem but differing by extension must not
    // collide on the same temp path. `Path::with_extension("agent-tmp")` mapped
    // both `x.md` and `x.exe` to `x.agent-tmp`; concurrent edits corrupted each
    // other and left an orphan temp file.
    #[tokio::test]
    async fn test_edit_same_stem_different_ext_no_collision() {
        let dir = std::env::temp_dir().join(format!("edit_collision_{}", std::process::id()));
        std::fs::create_dir_all(&dir).unwrap();
        let md = dir.join("x.md");
        let exe = dir.join("x.exe");
        std::fs::write(&md, "hello from MD\ncommon").unwrap();
        std::fs::write(&exe, "hello from EXE\ncommon").unwrap();

        let tool = EditTool;
        let edit_md = tool.execute(
            json!({"path": md.to_string_lossy(), "old_string": "hello from MD", "new_string": "MD EDITED"}),
            create_tool_context(),
        );
        let edit_exe = tool.execute(
            json!({"path": exe.to_string_lossy(), "old_string": "hello from EXE", "new_string": "EXE EDITED"}),
            create_tool_context(),
        );
        // Drive both concurrently to exercise the temp-path race.
        let (r_md, r_exe) = tokio::join!(edit_md, edit_exe);
        r_md.unwrap();
        r_exe.unwrap();

        // Each file keeps its own edited content — no cross-contamination.
        let md_content = std::fs::read_to_string(&md).unwrap();
        let exe_content = std::fs::read_to_string(&exe).unwrap();
        assert!(md_content.contains("MD EDITED"), "md content: {md_content:?}");
        assert!(!md_content.contains("EXE"), "md leaked exe content: {md_content:?}");
        assert!(exe_content.contains("EXE EDITED"), "exe content: {exe_content:?}");
        assert!(!exe_content.contains("from MD"), "exe leaked md content: {exe_content:?}");

        // No orphan temp files left behind.
        let leftovers: Vec<_> = std::fs::read_dir(&dir)
            .unwrap()
            .filter_map(|e| e.ok())
            .filter(|e| e.file_name().to_string_lossy().contains("agent-tmp"))
            .collect();
        assert!(leftovers.is_empty(), "orphan temp files: {leftovers:?}");

        let _ = std::fs::remove_dir_all(&dir);
    }
}