fix: classify file content conflicts as retryable

crates/tools/src/edit.rs

@@ -298,7 +298,12 @@ mod tests {
             .execute(&inp.to_string(), Default::default())
             .await
             .unwrap_err();
-        let msg = format!("{err}");
-        assert!(msg.contains("modified externally"), "{msg}");
+        match err {
+            ToolError::ExecutionFailed(message) => assert_eq!(
+                message,
+                "The target file's content or existence changed since it was last observed; read the file again before retrying: a.txt"
+            ),
+            other => panic!("expected execution failure, got {other:?}"),
+        }
     }
 }

crates/tools/src/error.rs

@@ -43,7 +43,8 @@ impl From<ToolsError> for ToolError {
                 | workdir::WorkdirError::Io { .. }
                 | workdir::WorkdirError::Unavailable(_)
                 | workdir::WorkdirError::OperationFailed
-                | workdir::WorkdirError::Transport(_),
+                | workdir::WorkdirError::Transport(_)
+                | workdir::WorkdirError::Conflict(_),
             ) => ToolError::ExecutionFailed(err.to_string()),
             ToolsError::FileSystem(_)
             | ToolsError::WorkdirSession(_)
@@ -55,3 +56,48 @@ impl From<ToolsError> for ToolError {
         }
     }
 }
+
+#[cfg(test)]
+mod tests {
+    use super::*;
+    use workdir::http::{WorkdirTransportError, WorkdirTransportErrorCode};
+
+    #[test]
+    fn local_workdir_content_conflict_is_retryable_execution_failure() {
+        let error = ToolError::from(ToolsError::WorkdirSession(
+            fs_operation::FsError::Conflict("src/main.rs".to_string()).into(),
+        ));
+
+        match error {
+            ToolError::ExecutionFailed(message) => assert_eq!(
+                message,
+                "The target file's content or existence changed since it was last observed; read the file again before retrying: src/main.rs"
+            ),
+            other => panic!("expected execution failure, got {other:?}"),
+        }
+    }
+
+    #[test]
+    fn remote_workdir_content_conflict_is_retryable_without_host_path() {
+        let transport = WorkdirTransportError::from_workdir_error(
+            &workdir::WorkdirError::Conflict("/runtime/private/checkout/src/main.rs".to_string()),
+        );
+        assert_eq!(transport.code, WorkdirTransportErrorCode::Conflict);
+        assert_eq!(
+            transport.message,
+            "The target file's content or existence changed since it was last observed; read the file again before retrying"
+        );
+        let error = ToolError::from(ToolsError::WorkdirSession(transport.into_workdir_error()));
+
+        match error {
+            ToolError::ExecutionFailed(message) => {
+                assert_eq!(
+                    message,
+                    "The target file's content or existence changed since it was last observed; read the file again before retrying"
+                );
+                assert!(!message.contains("/runtime/private"));
+            }
+            other => panic!("expected execution failure, got {other:?}"),
+        }
+    }
+}

crates/tools/src/write.rs

@@ -219,8 +219,13 @@ mod tests {
             )
             .await
             .unwrap_err();
-        let msg = format!("{err}");
-        assert!(msg.contains("modified externally"), "{msg}");
+        match err {
+            ToolError::ExecutionFailed(message) => assert_eq!(
+                message,
+                "The target file's content or existence changed since it was last observed; read the file again before retrying: a.txt"
+            ),
+            other => panic!("expected execution failure, got {other:?}"),
+        }
     }
 
     #[tokio::test]