WIP

crates/harness-tools/src/bash.rs

@@ -151,6 +151,7 @@ mod tests {
             metadata,
             spawner: None,
             context_reporter: None,
+            diagnostics: None,
         }
     }
 

crates/harness-tools/src/diagnostics.rs

@@ -0,0 +1,68 @@
+//! Shared LSP-diagnostics reporting for the edit/write tools. After a file is written we ask
+//! the (optional) diagnostics source to re-analyze it and append any error-severity items to
+//! the tool output so the model sees mistakes it just introduced. Best-effort: no source, a
+//! slow server, or a timeout all just mean "no diagnostics" — never a tool failure.
+
+use std::path::Path;
+use std::time::Duration;
+
+use harness_core::lsp::Severity;
+use harness_core::tool::{ToolCtx, ToolOutput};
+
+/// docs/09-integrations.md: wait up to 1.5s for the server to (re)publish after the change.
+const DIAGNOSTICS_WAIT: Duration = Duration::from_millis(1500);
+
+/// Touches `path` in the language server and appends error-severity diagnostics to `output`
+/// (both as a human-readable block in the text and the full set in metadata under `diagnostics`).
+pub async fn append_diagnostics(ctx: &ToolCtx, path: &Path, display_name: &str, output: &mut ToolOutput) {
+    let Some(source) = &ctx.diagnostics else {
+        return;
+    };
+    source.touch(path).await;
+    let diagnostics = source.diagnostics(path, DIAGNOSTICS_WAIT).await;
+    if diagnostics.is_empty() {
+        return;
+    }
+
+    let errors: Vec<_> = diagnostics
+        .iter()
+        .filter(|d| d.severity == Severity::Error)
+        .collect();
+    if !errors.is_empty() {
+        output
+            .output
+            .push_str("\n\nLSP errors detected in this file, please fix:");
+        for diag in &errors {
+            output.output.push('\n');
+            output.output.push_str(&diag.display_line(display_name));
+        }
+    }
+
+    // Full set (all severities) into metadata for the TUI.
+    let items: Vec<serde_json::Value> = diagnostics
+        .iter()
+        .map(|d| {
+            serde_json::json!({
+                "line": d.line,
+                "character": d.character,
+                "severity": severity_str(d.severity),
+                "message": d.message,
+                "source": d.source,
+            })
+        })
+        .collect();
+    if let serde_json::Value::Object(map) = &mut output.metadata {
+        map.insert("diagnostics".into(), serde_json::Value::Array(items));
+    } else {
+        output.metadata = serde_json::json!({ "diagnostics": items });
+    }
+}
+
+fn severity_str(severity: Severity) -> &'static str {
+    match severity {
+        Severity::Error => "error",
+        Severity::Warning => "warning",
+        Severity::Info => "info",
+        Severity::Hint => "hint",
+    }
+}

crates/harness-tools/src/edit/mod.rs

@@ -196,8 +196,9 @@ impl Tool for EditTool {
             .map_err(|e| ToolError::Other(format!("{}: {e}", path.display())))?;
 
         let (added, removed) = diff_stats(&content_old, &content_new);
-        let mut output = ToolOutput::new(pattern, "Edit applied successfully.".to_string());
+        let mut output = ToolOutput::new(pattern.clone(), "Edit applied successfully.".to_string());
         output.metadata = serde_json::json!({"diff": diff, "added": added, "removed": removed});
+        crate::diagnostics::append_diagnostics(&ctx, &path, &pattern, &mut output).await;
         Ok(output)
     }
 }
@@ -234,6 +235,7 @@ mod tests {
             metadata,
             spawner: None,
             context_reporter: None,
+            diagnostics: None,
         }
     }
 

crates/harness-tools/src/glob.rs

@@ -132,6 +132,7 @@ mod tests {
             metadata,
             spawner: None,
             context_reporter: None,
+            diagnostics: None,
         }
     }
 

crates/harness-tools/src/grep.rs

@@ -161,6 +161,7 @@ mod tests {
             metadata,
             spawner: None,
             context_reporter: None,
+            diagnostics: None,
         }
     }
 

crates/harness-tools/src/lib.rs

@@ -1,4 +1,5 @@
 mod bash;
+mod diagnostics;
 mod edit;
 mod glob;
 mod grep;

crates/harness-tools/src/read.rs

@@ -148,6 +148,7 @@ mod tests {
             metadata,
             spawner: None,
             context_reporter: None,
+            diagnostics: None,
         }
     }
 

crates/harness-tools/src/write.rs

@@ -80,6 +80,7 @@ impl Tool for WriteTool {
             format!("wrote {} bytes", params.content.len()),
         );
         output.metadata = serde_json::json!({"diff": diff, "added": added, "removed": removed});
+        crate::diagnostics::append_diagnostics(&ctx, &path, &params.file_path, &mut output).await;
         Ok(output)
     }
 }
@@ -116,6 +117,7 @@ mod tests {
             metadata,
             spawner: None,
             context_reporter: None,
+            diagnostics: None,
         }
     }