zig fmt: preserve formatting for function parameters with doc comments

lib/std/Build/WebServer.zig

@@ -672,20 +672,23 @@ fn buildClientWasm(ws: *WebServer, arena: Allocator, optimize: std.builtin.Optim
     return base_path.join(arena, bin_name);
 }
 
-pub fn updateTimeReportCompile(ws: *WebServer, opts: struct {
-    compile: *Build.Step.Compile,
+pub fn updateTimeReportCompile(
+    ws: *WebServer,
+    opts: struct {
+        compile: *Build.Step.Compile,
 
-    use_llvm: bool,
-    stats: abi.time_report.CompileResult.Stats,
-    ns_total: u64,
+        use_llvm: bool,
+        stats: abi.time_report.CompileResult.Stats,
+        ns_total: u64,
 
-    llvm_pass_timings_len: u32,
-    files_len: u32,
-    decls_len: u32,
+        llvm_pass_timings_len: u32,
+        files_len: u32,
+        decls_len: u32,
 
-    /// The trailing data of `abi.time_report.CompileResult`, except the step name.
-    trailing: []const u8,
-}) void {
+        /// The trailing data of `abi.time_report.CompileResult`, except the step name.
+        trailing: []const u8,
+    },
+) void {
     const gpa = ws.gpa;
 
     const step_idx: u32 = for (ws.all_steps, 0..) |s, i| {

lib/std/time/epoch.zig

@@ -182,14 +182,19 @@ pub const EpochSeconds = struct {
     }
 };
 
-fn testEpoch(secs: u64, expected_year_day: YearAndDay, expected_month_day: MonthAndDay, expected_day_seconds: struct {
-    /// 0 to 23
-    hours_into_day: u5,
-    /// 0 to 59
-    minutes_into_hour: u6,
-    /// 0 to 59
-    seconds_into_minute: u6,
-}) !void {
+fn testEpoch(
+    secs: u64,
+    expected_year_day: YearAndDay,
+    expected_month_day: MonthAndDay,
+    expected_day_seconds: struct {
+        /// 0 to 23
+        hours_into_day: u5,
+        /// 0 to 59
+        minutes_into_hour: u6,
+        /// 0 to 59
+        seconds_into_minute: u6,
+    },
+) !void {
     const epoch_seconds = EpochSeconds{ .secs = secs };
     const epoch_day = epoch_seconds.getEpochDay();
     const day_seconds = epoch_seconds.getDaySeconds();

lib/std/zig/Ast/Render.zig

@@ -1718,7 +1718,18 @@ fn renderFnProto(r: *Render, fn_proto: Ast.full.FnProto, space: Space) Error!voi
     // The params list is a sparse set that does *not* include anytype or ... parameters.
 
     const trailing_comma = tree.tokenTag(rparen - 1) == .comma;
-    if (!trailing_comma and !hasComment(tree, lparen, rparen)) {
+
+    // Check if there are any doc comment tokens between lparen and rparen
+    var has_doc_comment = false;
+    for (lparen..rparen) |i| {
+        const token: Ast.TokenIndex = @intCast(i);
+        if (tree.tokenTag(token) == .doc_comment) {
+            has_doc_comment = true;
+            break;
+        }
+    }
+
+    if (!trailing_comma and !hasComment(tree, lparen, rparen) and !has_doc_comment) {
         // Render all on one line, no trailing comma.
         try renderToken(r, lparen, .none); // (
 

lib/std/zig/parser_test.zig

@@ -1342,6 +1342,24 @@ test "zig fmt: doc comments on param decl" {
     );
 }
 
+test "zig fmt: doc comments on param decl without trailing comma" {
+    try testTransform(
+        \\fn f(
+        \\    /// comment
+        \\    x: u32,
+        \\    y: u32
+        \\) void {}
+        \\
+    ,
+        \\fn f(
+        \\    /// comment
+        \\    x: u32,
+        \\    y: u32,
+        \\) void {}
+        \\
+    );
+}
+
 test "zig fmt: aligned struct field" {
     try testCanonical(
         \\pub const S = struct {