Expose apply_patch preflight metadata

crates/tui/src/core/engine.rs

@@ -1987,7 +1987,7 @@ use self::dispatch::{
 };
 use self::loop_guard::{AttemptDecision, LoopGuard, OutcomeDecision};
 #[cfg(test)]
-use self::lsp_hooks::{edited_paths_for_tool, parse_patch_paths};
+use self::lsp_hooks::edited_paths_for_tool;
 #[cfg(test)]
 use self::streaming::TOOL_CALL_START_MARKERS;
 use self::streaming::{

crates/tui/src/core/engine/lsp_hooks.rs

@@ -7,6 +7,8 @@
 
 use std::path::PathBuf;
 
+use crate::tools::apply_patch::preflight_apply_patch;
+
 use super::*;
 
 /// #136: derive the file path(s) edited by a tool call. Returns the empty
@@ -22,54 +24,19 @@ pub(super) fn edited_paths_for_tool(tool_name: &str, input: &serde_json::Value)
                 Vec::new()
             }
         }
-        "apply_patch" => {
-            // `apply_patch` accepts either a `path` override or a list of
-            // `files` (each `{path, content}`). We try both shapes.
-            let mut out = Vec::new();
-            if let Some(path) = input.get("path").and_then(|v| v.as_str()) {
-                out.push(PathBuf::from(path));
-            }
-            if let Some(files) = input.get("files").and_then(|v| v.as_array()) {
-                for entry in files {
-                    if let Some(path) = entry.get("path").and_then(|v| v.as_str()) {
-                        out.push(PathBuf::from(path));
-                    }
-                }
-            }
-            // Fallback: parse `---`/`+++` headers from a unified diff payload.
-            if out.is_empty()
-                && let Some(patch) = input.get("patch").and_then(|v| v.as_str())
-            {
-                out.extend(parse_patch_paths(patch));
-            }
-            out
-        }
+        "apply_patch" => preflight_apply_patch(input)
+            .map(|preflight| {
+                preflight
+                    .touched_files
+                    .into_iter()
+                    .map(PathBuf::from)
+                    .collect()
+            })
+            .unwrap_or_default(),
         _ => Vec::new(),
     }
 }
 
-/// Lightweight parser for `+++ b/<path>` lines in a unified diff. Used as a
-/// fallback when `apply_patch` is invoked with raw `patch` text and no
-/// `path`/`files` override. We deliberately keep this dumb — the real
-/// `apply_patch` tool already validates the patch shape; we only need a
-/// best-effort hint for the LSP hook.
-pub(super) fn parse_patch_paths(patch: &str) -> Vec<PathBuf> {
-    let mut out = Vec::new();
-    for line in patch.lines() {
-        if let Some(rest) = line.strip_prefix("+++ ") {
-            let trimmed = rest.trim();
-            // Strip leading `b/` per git diff conventions.
-            let path = trimmed.strip_prefix("b/").unwrap_or(trimmed);
-            // Skip `/dev/null` (deletion).
-            if path == "/dev/null" {
-                continue;
-            }
-            out.push(PathBuf::from(path));
-        }
-    }
-    out
-}
-
 impl Engine {
     /// #136: post-edit hook. Inspects the tool name + input, derives the
     /// edited file path, and asks the LSP manager for diagnostics. The

crates/tui/src/core/engine/tests.rs

@@ -2233,9 +2233,9 @@ fn edited_paths_for_write_file_returns_path() {
 }
 
 #[test]
-fn edited_paths_for_apply_patch_with_files_returns_each_path() {
+fn edited_paths_for_apply_patch_with_changes_returns_each_path() {
     let input = json!({
-        "files": [
+        "changes": [
             { "path": "a.rs", "content": "" },
             { "path": "b.rs", "content": "" }
         ]
@@ -2253,6 +2253,15 @@ fn edited_paths_for_apply_patch_with_diff_text_extracts_paths() {
     assert_eq!(paths, vec![PathBuf::from("foo.rs")]);
 }
 
+#[test]
+fn edited_paths_for_apply_patch_with_invalid_diff_returns_empty() {
+    let input = json!({
+        "patch": "@@ -1 +1 @@\n-old\n+new\n"
+    });
+    let paths = edited_paths_for_tool("apply_patch", &input);
+    assert!(paths.is_empty());
+}
+
 #[test]
 fn edited_paths_for_unknown_tool_returns_empty() {
     let input = json!({ "path": "irrelevant.rs" });
@@ -2264,8 +2273,8 @@ fn edited_paths_for_unknown_tool_returns_empty() {
 
 #[test]
 fn parse_patch_paths_skips_dev_null() {
-    let patch = "--- a/keep.rs\n+++ b/keep.rs\n--- a/deleted.rs\n+++ /dev/null\n";
-    let paths = parse_patch_paths(patch);
+    let patch = "--- a/keep.rs\n+++ b/keep.rs\n@@ -1 +1 @@\n-old\n+new\n--- a/deleted.rs\n+++ /dev/null\n@@ -1 +0,0 @@\n-delete me\n";
+    let paths = edited_paths_for_tool("apply_patch", &json!({ "patch": patch }));
     assert_eq!(paths, vec![PathBuf::from("keep.rs")]);
 }