fix(chat): thread path:line refs through file open

apps/desktop/src/components/workpanel/FilesTab.tsx

@@ -215,17 +215,28 @@ export function FilesTab() {
     [dirs, loadDir],
   );
 
-  const openFile = useCallback(async (rel: string, mimeType?: string) => {
-    setSelected(rel);
-    setSelectedMimeType(mimeType);
-    setFile(null);
-    setFileError(false);
-    try {
-      setFile(await api.fsRead(rel, mimeType));
-    } catch {
-      setFileError(true);
-    }
-  }, []);
+  const openFile = useCallback(
+    async (rel: string, mimeType?: string, position?: { line?: number; column?: number }) => {
+      setSelected(rel);
+      setSelectedMimeType(mimeType);
+      setFile(null);
+      setFileError(false);
+      try {
+        setFile(await api.fsRead(rel, mimeType));
+        if (position?.line != null) {
+          requestAnimationFrame(() => {
+            const lineNode = document.querySelector(
+              `.work-files-preview [data-line="${position.line}"]`,
+            );
+            lineNode?.scrollIntoView({ block: "center" });
+          });
+        }
+      } catch {
+        setFileError(true);
+      }
+    },
+    [],
+  );
 
   const openMp4 = useCallback(async () => {
     if (!selected) return;
@@ -260,7 +271,10 @@ export function FilesTab() {
       setExpanded((prev) => new Set([...prev, ...ancestors]));
       for (const dir of ancestors) void loadDir(dir);
     }
-    void openFile(path, fileRequest.mimeType);
+    void openFile(path, fileRequest.mimeType, {
+      line: fileRequest.line,
+      column: fileRequest.column,
+    });
   }, [fileRequest, root, loadDir, openFile]);
 
   const renderDir = (rel: string, depth: number): React.ReactNode => {

apps/desktop/src/features/chat/transcript/shared.tsx

@@ -418,13 +418,22 @@ export function FileRefChip({
   kind,
   mimeType,
   onOpen,
+  line,
+  column,
   ...position
 }: {
   name: string;
   path: string;
   kind?: "image" | "file";
   mimeType?: string;
-  onOpen: (path: string, baseDir?: string, mimeType?: string) => void;
+  onOpen: (
+    path: string,
+    baseDir?: string,
+    mimeType?: string,
+    position?: { line?: number; column?: number },
+  ) => void;
+  line?: number;
+  column?: number;
 } & SourcePositionProps) {
   const { t } = useTranslation();
   const Icon = fileChipIcon(name, kind);
@@ -438,7 +447,7 @@ export function FileRefChip({
         {...position}
         title={`${html ? t("chat.previewUrl") : t("chat.openFile")} — ${path}`}
         aria-label={`${name} — ${path}`}
-        onClick={() => onOpen(path, undefined, mimeType)}
+        onClick={() => onOpen(path, undefined, mimeType, { line, column })}
         onContextMenu={(event) => openFileMenu(event, { path })}
       >
         <span className="composer-chip-icon" aria-hidden>
@@ -515,6 +524,8 @@ export function LinkifiedText({ text, attachments }: { text: string; attachments
             key={index}
             name={segment.label}
             path={segment.target.path}
+            line={segment.target.line}
+            column={segment.target.column}
             onOpen={openFileRef}
             {...position}
           />

apps/desktop/src/hooks/use-preview-target.ts

@@ -27,7 +27,12 @@ export function useOpenPreviewTarget() {
   const openFileRef = useOpenChatFileRef();
   return useCallback(
     (target: ChatPreviewTarget) =>
-      target.kind === "file" ? openFileRef(target.path) : openHttpUrl(target.url),
+      target.kind === "file"
+        ? openFileRef(target.path, undefined, undefined, {
+            line: target.line,
+            column: target.column,
+          })
+        : openHttpUrl(target.url),
     [openFileRef],
   );
 }
@@ -144,7 +149,14 @@ export function useOpenChatFileRef() {
   );
 
   return useCallback(
-    (path: string, baseDir?: string, mimeType?: string) => {
+    (
+      path: string,
+      baseDir?: string,
+      mimeType?: string,
+      position?: { line?: number; column?: number },
+    ) => {
+      const line = position?.line;
+      const column = position?.column;
       void (async () => {
         const resolved = await resolveRef(path, baseDir);
         if (!resolved) return;
@@ -158,10 +170,12 @@ export function useOpenChatFileRef() {
           return;
         }
         if (resolved.inProject && fileViewAvailable) {
-          openTab(fileManagerPluginTab(resolved.path));
+          // Thread path:line into the plugin tab so the bundled file view can
+          // scroll to the line (#681 / #1149 review). Host fallback uses openFile.
+          openTab(fileManagerPluginTab(resolved.path, { line, column }));
           return;
         }
-        openFile(resolved.path, mimeType);
+        openFile(resolved.path, mimeType, { line, column });
       })();
     },
     [fileViewAvailable, openFile, openTab, openUrl, resolveRef],

apps/desktop/src/lib/chat-links.ts

@@ -55,6 +55,20 @@ function stripLineRef(path: string): string {
   return path.replace(/:\d+(?::\d+)?$/, "");
 }
 
+/** Trailing `:line[:col]` on a file token, if any. */
+export function parseFileRefPosition(
+  text: string,
+): { line: number; column?: number } | null {
+  const match = text.trim().match(/:(\d+)(?::(\d+))?$/);
+  if (!match) return null;
+  const line = Number(match[1]);
+  if (!Number.isFinite(line) || line < 1) return null;
+  const column = match[2] !== undefined ? Number(match[2]) : undefined;
+  return column !== undefined && Number.isFinite(column) && column >= 1
+    ? { line, column }
+    : { line };
+}
+
 function leafName(path: string): string {
   const normalized = path.replaceAll("\\", "/").replace(/\/+$/, "");
   return normalized.slice(normalized.lastIndexOf("/") + 1) || path;
@@ -182,7 +196,7 @@ export function toWorkspaceRel(
 }
 
 export type ChatPreviewTarget =
-  | { kind: "file"; path: string }
+  | { kind: "file"; path: string; line?: number; column?: number }
   | { kind: "url"; url: string };
 
 /** Resolve one raw chat token into a previewable target, or null. */
@@ -195,15 +209,19 @@ export function resolvePreviewTarget(
   if (isHttpUrl(trimmed)) return { kind: "url", url: trimmed };
   const at = unwrapAtFileRef(trimmed);
   if (at) {
-    // Scratch/attachment @refs stay absolute so fs/open can contain them.
-    if (at.startsWith("/")) return { kind: "file", path: at };
-    const rel = toWorkspaceRel(at, root, baseDir);
-    return rel ? { kind: "file", path: rel } : null;
+    const position = parseFileRefPosition(at);
+    const cleaned = stripLineRef(at);
+    if (cleaned.startsWith("/")) {
+      return { kind: "file", path: cleaned, ...(position ?? {}) };
+    }
+    const rel = toWorkspaceRel(cleaned, root, baseDir);
+    return rel ? { kind: "file", path: rel, ...(position ?? {}) } : null;
   }
   const file = parseFileRef(trimmed);
   if (!file) return null;
   const rel = toWorkspaceRel(file, root, baseDir);
-  return rel ? { kind: "file", path: rel } : null;
+  const position = parseFileRefPosition(trimmed);
+  return rel ? { kind: "file", path: rel, ...(position ?? {}) } : null;
 }
 
 /** Tool-call args → preview target (Read/Write/Edit paths, fetch URLs). */

apps/desktop/src/lib/work-panel-tabs.ts

@@ -15,6 +15,9 @@ export type WorkPanelTab = {
   location?: string;
   /** Stored attachment mimeType for extension-less `attachments/<sha256>` images. */
   mimeType?: string;
+  /** Optional 1-based line/column for host file tabs (chat `path:line` refs). */
+  line?: number;
+  column?: number;
 };
 
 export type WorkPanelTabsState = {
@@ -24,7 +27,13 @@ export type WorkPanelTabsState = {
 
 export type WorkPanelContext = WorkPanelTabsState & {
   open: boolean;
-  fileRequest: { path: string; seq: number; mimeType?: string } | null;
+  fileRequest: {
+    path: string;
+    seq: number;
+    mimeType?: string;
+    line?: number;
+    column?: number;
+  } | null;
 };
 
 let newWorkPanelTabSequence = 0;
@@ -145,14 +154,19 @@ export const FILE_MANAGER_PLUGIN_TAB = {
   viewId: "manager",
 } as const;
 
-/** The file view, asked to show one file. */
-export function fileManagerPluginTab(location: string): WorkPanelTab {
+/** The file view, asked to show one file (optional chat `path:line` position). */
+export function fileManagerPluginTab(
+  location: string,
+  position?: { line?: number; column?: number },
+): WorkPanelTab {
   return {
     ...pluginWorkPanelTab(
       FILE_MANAGER_PLUGIN_TAB.pluginId,
       FILE_MANAGER_PLUGIN_TAB.viewId,
     ),
     location,
+    ...(position?.line != null ? { line: position.line } : {}),
+    ...(position?.column != null ? { column: position.column } : {}),
   };
 }
 
@@ -267,13 +281,19 @@ export function normalizeWorkPanelFilePath(path: string): string {
   return absolute ? `/${normalized}` : normalized;
 }
 
-export function fileWorkPanelTab(path: string, mimeType?: string): WorkPanelTab {
+export function fileWorkPanelTab(
+  path: string,
+  mimeType?: string,
+  position?: { line?: number; column?: number },
+): WorkPanelTab {
   const resource = normalizeWorkPanelFilePath(path);
   return {
     id: `file:${resource}`,
     kind: "file",
     resource,
     ...(mimeType ? { mimeType } : {}),
+    ...(position?.line != null ? { line: position.line } : {}),
+    ...(position?.column != null ? { column: position.column } : {}),
   };
 }
 

apps/desktop/src/stores/app-state.ts

@@ -357,7 +357,13 @@ export type AppState = {
   workPanelContexts: Record<string, WorkPanelContext>;
   workPanelWidth: number;
   /** Chat-initiated "preview this file" request consumed by the files viewer. */
-  workPanelFileRequest: { path: string; seq: number; mimeType?: string } | null;
+  workPanelFileRequest: {
+    path: string;
+    seq: number;
+    mimeType?: string;
+    line?: number;
+    column?: number;
+  } | null;
   /** Open (or activate) the transcript tab of one delegated subagent. */
   openSubagentTab: (delegationId: string, agentName?: string) => void;
   /** Abort one session's running turn, visible or not. */
@@ -381,7 +387,11 @@ export type AppState = {
   /** Hide the visible panel while retaining its session-owned context. */
   resetWorkPanelContext: () => void;
   setWorkPanelWidth: (width: number) => void;
-  openFileInWorkPanel: (path: string, mimeType?: string) => void;
+  openFileInWorkPanel: (
+    path: string,
+    mimeType?: string,
+    position?: { line?: number; column?: number },
+  ) => void;
   openUrlInWorkPanel: (url: string) => void;
   updateBrowserWorkPanelTab: (state: BrowserState) => void;
 };

apps/desktop/src/stores/slices/work-panel-slice.ts

@@ -379,8 +379,8 @@ export function createWorkPanelSlice({
     saveWorkPanelWidth(get().workPanelWidth);
   },
 
-  openFileInWorkPanel: (path, mimeType) => {
-    get().openWorkPanelTab(fileWorkPanelTab(path, mimeType));
+  openFileInWorkPanel: (path, mimeType, position) => {
+    get().openWorkPanelTab(fileWorkPanelTab(path, mimeType, position));
   },
   updateBrowserWorkPanelTab: (event) => {
     const sessionId = event.sessionId;

apps/desktop/test/chat-links.test.mjs

@@ -6,6 +6,7 @@ import {
   isHttpUrl,
   linkifyMdastTree,
   parseFileRef,
+  parseFileRefPosition,
   remarkChatFileLinks,
   resolvePreviewTarget,
   splitChatText,
@@ -91,6 +92,7 @@ test("resolvePreviewTarget classifies urls and workspace files", () => {
   assert.deepEqual(resolvePreviewTarget("src/a.ts:10", ROOT), {
     kind: "file",
     path: "src/a.ts",
+    line: 10,
   });
   assert.deepEqual(resolvePreviewTarget("./README.md", ROOT, "docs"), {
     kind: "file",
@@ -350,3 +352,24 @@ test("adjacent parenthesis-wrapped URLs all remain independently linkable", () =
   assert.equal(segments.filter(s => s.kind === "target").length, 1000);
   assert.equal(segments.map(s => s.text).join(""), source);
 });
+
+test("parseFileRefPosition keeps :line[:col] that parseFileRef strips", () => {
+  assert.deepEqual(parseFileRefPosition("src/main.rs:42"), { line: 42 });
+  assert.deepEqual(parseFileRefPosition("src/main.rs:42:7"), { line: 42, column: 7 });
+  assert.equal(parseFileRefPosition("src/main.rs"), null);
+  assert.equal(parseFileRefPosition("src/main.rs:0"), null);
+});
+
+test("resolvePreviewTarget carries line/col on file chips (#681)", () => {
+  assert.deepEqual(resolvePreviewTarget("src/a.ts:42", ROOT), {
+    kind: "file",
+    path: "src/a.ts",
+    line: 42,
+  });
+  assert.deepEqual(resolvePreviewTarget("src/a.ts:42:7", ROOT), {
+    kind: "file",
+    path: "src/a.ts",
+    line: 42,
+    column: 7,
+  });
+});

apps/desktop/test/transcript-file-chips.test.mjs

@@ -25,7 +25,7 @@ test("sent user-message file refs render as composer-like chips", () => {
   assert.match(transcript, /composer-chip-name/);
   assert.match(styles, /\.chat-file-chip[\s\S]*?appearance: none/);
   assert.match(transcript, /mimeType=\{attachment\.mimeType\}/);
-  assert.match(transcript, /onOpen\(path, undefined, mimeType\)/);
+  assert.match(transcript, /onOpen\(path, undefined, mimeType, \{ line, column \}\)/);
 });
 
 test("a file chip is routed by where the reference resolved, never optimistically", () => {
@@ -47,7 +47,7 @@ test("a file chip is routed by where the reference resolved, never optimisticall
   // A project file prefers the bundled file view; without that plugin the
   // host file tab is the same surface this hook used before.
   assert.match(hook, /FILE_MANAGER_PLUGIN_TAB/);
-  assert.match(hook, /fileManagerPluginTab\(resolved\.path\)/);
+  assert.match(hook, /fileManagerPluginTab\(resolved\.path, \{ line, column \}\)/);
   // Session scratch and attachment files live outside the plugin's project
   // roots, so completion hands them back as an absolute path.
   assert.match(hook, /inProject: false/);