Introduce DiagnosticsTool (#26670)

Release Notes:

- N/A

crates/assistant_tools/src/diagnostics_tool.rs

@@ -0,0 +1,127 @@
+use anyhow::{anyhow, Result};
+use assistant_tool::Tool;
+use gpui::{App, Entity, Task};
+use language::{DiagnosticSeverity, OffsetRangeExt};
+use language_model::LanguageModelRequestMessage;
+use project::Project;
+use schemars::JsonSchema;
+use serde::{Deserialize, Serialize};
+use std::{
+    fmt::Write,
+    path::{Path, PathBuf},
+    sync::Arc,
+};
+
+#[derive(Debug, Serialize, Deserialize, JsonSchema)]
+pub struct DiagnosticsToolInput {
+    /// The path to get diagnostics for. If not provided, returns a project-wide summary.
+    ///
+    /// This path should never be absolute, and the first component
+    /// of the path should always be a root directory in a project.
+    ///
+    /// <example>
+    /// If the project has the following root directories:
+    ///
+    /// - lorem
+    /// - ipsum
+    ///
+    /// If you wanna access diagnostics for `dolor.txt` in `ipsum`, you should use the path `ipsum/dolor.txt`.
+    /// </example>
+    pub path: Option<PathBuf>,
+}
+
+pub struct DiagnosticsTool;
+
+impl Tool for DiagnosticsTool {
+    fn name(&self) -> String {
+        "diagnostics".into()
+    }
+
+    fn description(&self) -> String {
+        include_str!("./diagnostics_tool/description.md").into()
+    }
+
+    fn input_schema(&self) -> serde_json::Value {
+        let schema = schemars::schema_for!(DiagnosticsToolInput);
+        serde_json::to_value(&schema).unwrap()
+    }
+
+    fn run(
+        self: Arc<Self>,
+        input: serde_json::Value,
+        _messages: &[LanguageModelRequestMessage],
+        project: Entity<Project>,
+        cx: &mut App,
+    ) -> Task<Result<String>> {
+        let input = match serde_json::from_value::<DiagnosticsToolInput>(input) {
+            Ok(input) => input,
+            Err(err) => return Task::ready(Err(anyhow!(err))),
+        };
+
+        if let Some(path) = input.path {
+            let Some(project_path) = project.read(cx).find_project_path(&path, cx) else {
+                return Task::ready(Err(anyhow!("Could not find path in project")));
+            };
+            let buffer = project.update(cx, |project, cx| project.open_buffer(project_path, cx));
+
+            cx.spawn(|cx| async move {
+                let mut output = String::new();
+                let buffer = buffer.await?;
+                let snapshot = buffer.read_with(&cx, |buffer, _cx| buffer.snapshot())?;
+
+                for (_, group) in snapshot.diagnostic_groups(None) {
+                    let entry = &group.entries[group.primary_ix];
+                    let range = entry.range.to_point(&snapshot);
+                    let severity = match entry.diagnostic.severity {
+                        DiagnosticSeverity::ERROR => "error",
+                        DiagnosticSeverity::WARNING => "warning",
+                        _ => continue,
+                    };
+
+                    writeln!(
+                        output,
+                        "{} at line {}: {}",
+                        severity,
+                        range.start.row + 1,
+                        entry.diagnostic.message
+                    )?;
+                }
+
+                if output.is_empty() {
+                    Ok("File doesn't have errors or warnings!".to_string())
+                } else {
+                    Ok(output)
+                }
+            })
+        } else {
+            let project = project.read(cx);
+            let mut output = String::new();
+            let mut has_diagnostics = false;
+
+            for (project_path, _, summary) in project.diagnostic_summaries(true, cx) {
+                if summary.error_count > 0 || summary.warning_count > 0 {
+                    let Some(worktree) = project.worktree_for_id(project_path.worktree_id, cx)
+                    else {
+                        continue;
+                    };
+
+                    has_diagnostics = true;
+                    output.push_str(&format!(
+                        "{}: {} error(s), {} warning(s)\n",
+                        Path::new(worktree.read(cx).root_name())
+                            .join(project_path.path)
+                            .display(),
+                        summary.error_count,
+                        summary.warning_count
+                    ));
+                }
+            }
+
+            if has_diagnostics {
+                Task::ready(Ok(output))
+            } else {
+                Task::ready(Ok("No errors or warnings found in the project.".to_string()))
+            }
+        }
+    }
+}