Prove multi-file terminal coding loop

src/tui.zig

@@ -474,6 +474,10 @@ pub const Client = struct {
         return self.saved_bytes orelse Error.NothingSaved;
     }
 
+    pub fn currentPath(self: *const Client) ?[]const u8 {
+        return self.current_path;
+    }
+
     pub fn snapshotBytesAlloc(self: *const Client, allocator: std.mem.Allocator) ![]u8 {
         const snap = try self.session.snapshot();
         return allocator.dupe(u8, snap.bytes);
@@ -487,6 +491,10 @@ pub const Client = struct {
         return self.discard_on_quit;
     }
 
+    pub fn openFilePicker(self: *Client) !void {
+        try self.openFilePickerPanel();
+    }
+
     pub fn clearQuit(self: *Client) void {
         self.quit = false;
         self.discard_on_quit = false;
@@ -669,11 +677,18 @@ pub const Client = struct {
         const path = repo_mod.gitPathFromStatusRow(selected) catch return Error.ProtocolRejected;
         const content = repo_mod.readRepoFileAlloc(self.allocator, io, cwd, path) catch return Error.ProtocolRejected;
         defer self.allocator.free(content);
-        try self.session.openFixture(content);
+        try self.openRepoContentAtPath(path, content, 0);
         try self.session.closePanel();
         self.message = null;
     }
 
+    fn openRepoContentAtPath(self: *Client, path: []const u8, content: []const u8, cursor: usize) !void {
+        if (self.current_path) |old| self.allocator.free(old);
+        self.current_path = try self.allocator.dupe(u8, path);
+        try self.session.openFixtureAt(content, cursor);
+        self.message = null;
+    }
+
     fn openJobRun(self: *Client, cwd_and_command: []const u8) !void {
         const io = self.io orelse return Error.ProtocolRejected;
         const split = splitCwdAndCommand(cwd_and_command) orelse return Error.ProtocolRejected;
@@ -2239,9 +2254,13 @@ pub const Client = struct {
                 self.message = "quit:discard";
             },
             .open => |path| {
-                const line = try std.fmt.allocPrint(self.allocator, "open {s}", .{path});
-                defer self.allocator.free(line);
-                try self.applyProtocol(line);
+                if (self.repo.content(path)) |content| {
+                    try self.openRepoContentAtPath(path, content, 0);
+                } else |_| {
+                    const line = try std.fmt.allocPrint(self.allocator, "open {s}", .{path});
+                    defer self.allocator.free(line);
+                    try self.applyProtocol(line);
+                }
             },
             .symbol => |symbol| try self.applyProtocol(symbol_mod.protocolCommand(symbol)),
             .file_picker => try self.openFilePickerPanel(),