agent: improve eval parsing and command recording

- Extract `getJsonString` helper in Agent.zig.
- Match specific triple quote types in EVAL blocks to allow nested quotes.
- Use `cmd.format` and larger buffers in Recorder.zig.

src/agent/Agent.zig

@@ -415,31 +415,22 @@ fn toolCallToCommand(arena: std.mem.Allocator, tool_name: []const u8, arguments:
         else => return null,
     };
 
-    const getString = struct {
-        fn f(o: std.json.ObjectMap, key: []const u8) ?[]const u8 {
-            return switch (o.get(key) orelse return null) {
-                .string => |s| s,
-                else => null,
-            };
-        }
-    }.f;
-
     return switch (action) {
-        .goto => .{ .goto = getString(obj, "url") orelse return null },
-        .click => .{ .click = getString(obj, "selector") orelse return null },
-        .hover => .{ .hover = getString(obj, "selector") orelse return null },
-        .eval => .{ .eval_js = getString(obj, "script") orelse return null },
-        .waitForSelector => .{ .wait = getString(obj, "selector") orelse return null },
+        .goto => .{ .goto = getJsonString(obj, "url") orelse return null },
+        .click => .{ .click = getJsonString(obj, "selector") orelse return null },
+        .hover => .{ .hover = getJsonString(obj, "selector") orelse return null },
+        .eval => .{ .eval_js = getJsonString(obj, "script") orelse return null },
+        .waitForSelector => .{ .wait = getJsonString(obj, "selector") orelse return null },
         .fill => .{ .type_cmd = .{
-            .selector = getString(obj, "selector") orelse return null,
-            .value = getString(obj, "value") orelse return null,
+            .selector = getJsonString(obj, "selector") orelse return null,
+            .value = getJsonString(obj, "value") orelse return null,
         } },
         .selectOption => .{ .select = .{
-            .selector = getString(obj, "selector") orelse return null,
-            .value = getString(obj, "value") orelse return null,
+            .selector = getJsonString(obj, "selector") orelse return null,
+            .value = getJsonString(obj, "value") orelse return null,
         } },
         .setChecked => .{ .check = .{
-            .selector = getString(obj, "selector") orelse return null,
+            .selector = getJsonString(obj, "selector") orelse return null,
             .checked = switch (obj.get("checked") orelse return null) {
                 .bool => |b| b,
                 else => return null,
@@ -461,6 +452,13 @@ fn toolCallToCommand(arena: std.mem.Allocator, tool_name: []const u8, arguments:
     };
 }
 
+fn getJsonString(o: std.json.ObjectMap, key: []const u8) ?[]const u8 {
+    return switch (o.get(key) orelse return null) {
+        .string => |s| s,
+        else => null,
+    };
+}
+
 fn getEnvApiKey(provider_type: Config.AiProvider) ?[:0]const u8 {
     return switch (provider_type) {
         .anthropic => std.posix.getenv("ANTHROPIC_API_KEY"),

src/agent/Command.zig

@@ -248,9 +248,9 @@ pub const ScriptIterator = struct {
             const trimmed = std.mem.trim(u8, line, &std.ascii.whitespace);
             if (trimmed.len == 0) continue;
 
-            if (isEvalTripleQuote(trimmed)) {
+            if (isEvalTripleQuote(trimmed)) |quote_type| {
                 const start_line = self.line_num;
-                if (self.collectEvalBlock()) |js| {
+                if (self.collectEvalBlock(quote_type)) |js| {
                     return .{
                         .line_num = start_line,
                         .raw_line = trimmed,
@@ -274,21 +274,23 @@ pub const ScriptIterator = struct {
         return null;
     }
 
-    fn isEvalTripleQuote(line: []const u8) bool {
+    fn isEvalTripleQuote(line: []const u8) ?[]const u8 {
         const cmd_end = std.mem.indexOfAny(u8, line, &std.ascii.whitespace) orelse line.len;
         const cmd_word = line[0..cmd_end];
-        if (!std.ascii.eqlIgnoreCase(cmd_word, "EVAL")) return false;
+        if (!std.ascii.eqlIgnoreCase(cmd_word, "EVAL")) return null;
         const rest = std.mem.trim(u8, line[cmd_end..], &std.ascii.whitespace);
-        return std.mem.startsWith(u8, rest, "\"\"\"") or std.mem.startsWith(u8, rest, "'''");
+        if (std.mem.startsWith(u8, rest, "\"\"\"")) return "\"\"\"";
+        if (std.mem.startsWith(u8, rest, "'''")) return "'''";
+        return null;
     }
 
-    /// Collect lines until closing triple quote (""" or '''), return the JS content.
-    fn collectEvalBlock(self: *ScriptIterator) ?[]const u8 {
+    /// Collect lines until matching closing triple quote, return the JS content.
+    fn collectEvalBlock(self: *ScriptIterator, quote_type: []const u8) ?[]const u8 {
         var parts: std.ArrayListUnmanaged(u8) = .empty;
         while (self.lines.next()) |line| {
             self.line_num += 1;
             const trimmed = std.mem.trim(u8, line, &std.ascii.whitespace);
-            if (std.mem.eql(u8, trimmed, "\"\"\"") or std.mem.eql(u8, trimmed, "'''")) {
+            if (std.mem.eql(u8, trimmed, quote_type)) {
                 return parts.toOwnedSlice(self.allocator) catch null;
             }
             if (parts.items.len > 0) {
@@ -671,6 +673,21 @@ test "ScriptIterator unterminated EVAL" {
     try std.testing.expectEqualStrings("unterminated EVAL block", e1.command.natural_language);
 }
 
+test "ScriptIterator multi-line EVAL mismatched triple quote" {
+    const script =
+        \\EVAL """
+        \\  const s = " ''' ";
+        \\  console.log(s);
+        \\"""
+    ;
+    var iter: ScriptIterator = .init(script, std.testing.allocator);
+
+    const e1 = iter.next().?;
+    try std.testing.expect(e1.command == .eval_js);
+    try std.testing.expectEqualStrings("  const s = \" ''' \";\n  console.log(s);", e1.command.eval_js);
+    std.testing.allocator.free(e1.command.eval_js);
+}
+
 test "trimMatchingQuotes" {
     const cases = [_]struct { in: []const u8, out: ?[]const u8 }{
         .{ .in = "'hello'", .out = "hello" },

src/agent/Recorder.zig

@@ -37,16 +37,22 @@ pub fn record(self: *Self, cmd: Command.Command) void {
     const f = self.file orelse return;
     if (!cmd.isRecorded()) return;
 
-    var buf: [1024]u8 = undefined;
-    const line = std.fmt.bufPrint(&buf, "{f}\n", .{cmd}) catch return;
-    _ = f.write(line) catch return;
+    var buf: [8192]u8 = undefined;
+    var fba = std.heap.FixedBufferAllocator.init(&buf);
+    var aw: std.Io.Writer.Allocating = .init(fba.allocator());
+
+    cmd.format(&aw.writer) catch return;
+    aw.writer.writeByte('\n') catch return;
+
+    _ = f.write(aw.written()) catch return;
     self.needs_separator = true;
 }
 
 pub fn recordComment(self: *Self, comment: []const u8) void {
     const f = self.file orelse return;
-    var buf: [1024]u8 = undefined;
     const prefix: []const u8 = if (self.needs_separator) "\n# " else "# ";
+
+    var buf: [8192]u8 = undefined;
     const line = std.fmt.bufPrint(&buf, "{s}{s}\n", .{ prefix, comment }) catch return;
     _ = f.write(line) catch return;
     self.needs_separator = true;