Wire up find_path tool in agent2 (#35799)

Release Notes:

- N/A

---------

Co-authored-by: Antonio Scandurra <me@as-cii.com>

crates/agent2/src/tools/find_path_tool.rs

@@ -0,0 +1,231 @@
+use agent_client_protocol as acp;
+use anyhow::{anyhow, Result};
+use gpui::{App, AppContext, Entity, SharedString, Task};
+use project::Project;
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+use std::fmt::Write;
+use std::{cmp, path::PathBuf, sync::Arc};
+use util::paths::PathMatcher;
+
+use crate::{AgentTool, ToolCallEventStream};
+
+/// Fast file path pattern matching tool that works with any codebase size
+///
+/// - Supports glob patterns like "**/*.js" or "src/**/*.ts"
+/// - Returns matching file paths sorted alphabetically
+/// - Prefer the `grep` tool to this tool when searching for symbols unless you have specific information about paths.
+/// - Use this tool when you need to find files by name patterns
+/// - Results are paginated with 50 matches per page. Use the optional 'offset' parameter to request subsequent pages.
+#[derive(Debug, Serialize, Deserialize, JsonSchema)]
+pub struct FindPathToolInput {
+    /// The glob to match against every path in the project.
+    ///
+    /// <example>
+    /// If the project has the following root directories:
+    ///
+    /// - directory1/a/something.txt
+    /// - directory2/a/things.txt
+    /// - directory3/a/other.txt
+    ///
+    /// You can get back the first two paths by providing a glob of "*thing*.txt"
+    /// </example>
+    pub glob: String,
+
+    /// Optional starting position for paginated results (0-based).
+    /// When not provided, starts from the beginning.
+    #[serde(default)]
+    pub offset: usize,
+}
+
+#[derive(Debug, Serialize, Deserialize)]
+struct FindPathToolOutput {
+    paths: Vec<PathBuf>,
+}
+
+const RESULTS_PER_PAGE: usize = 50;
+
+pub struct FindPathTool {
+    project: Entity<Project>,
+}
+
+impl FindPathTool {
+    pub fn new(project: Entity<Project>) -> Self {
+        Self { project }
+    }
+}
+
+impl AgentTool for FindPathTool {
+    type Input = FindPathToolInput;
+
+    fn name(&self) -> SharedString {
+        "find_path".into()
+    }
+
+    fn kind(&self) -> acp::ToolKind {
+        acp::ToolKind::Search
+    }
+
+    fn initial_title(&self, input: Self::Input) -> SharedString {
+        format!("Find paths matching “`{}`”", input.glob).into()
+    }
+
+    fn run(
+        self: Arc<Self>,
+        input: Self::Input,
+        event_stream: ToolCallEventStream,
+        cx: &mut App,
+    ) -> Task<Result<String>> {
+        let search_paths_task = search_paths(&input.glob, self.project.clone(), cx);
+
+        cx.background_spawn(async move {
+            let matches = search_paths_task.await?;
+            let paginated_matches: &[PathBuf] = &matches[cmp::min(input.offset, matches.len())
+                ..cmp::min(input.offset + RESULTS_PER_PAGE, matches.len())];
+
+            event_stream.send_update(acp::ToolCallUpdateFields {
+                title: Some(if paginated_matches.len() == 0 {
+                    "No matches".into()
+                } else if paginated_matches.len() == 1 {
+                    "1 match".into()
+                } else {
+                    format!("{} matches", paginated_matches.len())
+                }),
+                content: Some(
+                    paginated_matches
+                        .iter()
+                        .map(|path| acp::ToolCallContent::Content {
+                            content: acp::ContentBlock::ResourceLink(acp::ResourceLink {
+                                uri: format!("file://{}", path.display()),
+                                name: path.to_string_lossy().into(),
+                                annotations: None,
+                                description: None,
+                                mime_type: None,
+                                size: None,
+                                title: None,
+                            }),
+                        })
+                        .collect(),
+                ),
+                raw_output: Some(serde_json::json!({
+                    "paths": &matches,
+                })),
+                ..Default::default()
+            });
+
+            if matches.is_empty() {
+                Ok("No matches found".into())
+            } else {
+                let mut message = format!("Found {} total matches.", matches.len());
+                if matches.len() > RESULTS_PER_PAGE {
+                    write!(
+                        &mut message,
+                        "\nShowing results {}-{} (provide 'offset' parameter for more results):",
+                        input.offset + 1,
+                        input.offset + paginated_matches.len()
+                    )
+                    .unwrap();
+                }
+
+                for mat in matches.iter().skip(input.offset).take(RESULTS_PER_PAGE) {
+                    write!(&mut message, "\n{}", mat.display()).unwrap();
+                }
+
+                Ok(message)
+            }
+        })
+    }
+}
+
+fn search_paths(glob: &str, project: Entity<Project>, cx: &mut App) -> Task<Result<Vec<PathBuf>>> {
+    let path_matcher = match PathMatcher::new([
+        // Sometimes models try to search for "". In this case, return all paths in the project.
+        if glob.is_empty() { "*" } else { glob },
+    ]) {
+        Ok(matcher) => matcher,
+        Err(err) => return Task::ready(Err(anyhow!("Invalid glob: {err}"))),
+    };
+    let snapshots: Vec<_> = project
+        .read(cx)
+        .worktrees(cx)
+        .map(|worktree| worktree.read(cx).snapshot())
+        .collect();
+
+    cx.background_spawn(async move {
+        Ok(snapshots
+            .iter()
+            .flat_map(|snapshot| {
+                let root_name = PathBuf::from(snapshot.root_name());
+                snapshot
+                    .entries(false, 0)
+                    .map(move |entry| root_name.join(&entry.path))
+                    .filter(|path| path_matcher.is_match(&path))
+            })
+            .collect())
+    })
+}
+
+#[cfg(test)]
+mod test {
+    use super::*;
+    use gpui::TestAppContext;
+    use project::{FakeFs, Project};
+    use settings::SettingsStore;
+    use util::path;
+
+    #[gpui::test]
+    async fn test_find_path_tool(cx: &mut TestAppContext) {
+        init_test(cx);
+
+        let fs = FakeFs::new(cx.executor());
+        fs.insert_tree(
+            "/root",
+            serde_json::json!({
+                "apple": {
+                    "banana": {
+                        "carrot": "1",
+                    },
+                    "bandana": {
+                        "carbonara": "2",
+                    },
+                    "endive": "3"
+                }
+            }),
+        )
+        .await;
+        let project = Project::test(fs.clone(), [path!("/root").as_ref()], cx).await;
+
+        let matches = cx
+            .update(|cx| search_paths("root/**/car*", project.clone(), cx))
+            .await
+            .unwrap();
+        assert_eq!(
+            matches,
+            &[
+                PathBuf::from("root/apple/banana/carrot"),
+                PathBuf::from("root/apple/bandana/carbonara")
+            ]
+        );
+
+        let matches = cx
+            .update(|cx| search_paths("**/car*", project.clone(), cx))
+            .await
+            .unwrap();
+        assert_eq!(
+            matches,
+            &[
+                PathBuf::from("root/apple/banana/carrot"),
+                PathBuf::from("root/apple/bandana/carbonara")
+            ]
+        );
+    }
+
+    fn init_test(cx: &mut TestAppContext) {
+        cx.update(|cx| {
+            let settings_store = SettingsStore::test(cx);
+            cx.set_global(settings_store);
+            language::init(cx);
+            Project::init_settings(cx);
+        });
+    }
+}