Commit ee5f9ffad0

@@ -1406,7 +1406,7 @@ pub fn parse(allocator: &mem.Allocator, source: []const u8) !ast.Tree {
             },
 
             State.SwitchCaseCommaOrEnd => |list_state| {
-                switch (expectCommaOrEnd(&tok_it, &tree, Token.Id.RParen)) {
+                switch (expectCommaOrEnd(&tok_it, &tree, Token.Id.RBrace)) {
                     ExpectCommaOrEndResult.end_token => |maybe_end| if (maybe_end) |end| {
                         *list_state.ptr = end;
                         continue;

@@ -1,3 +1,34 @@
+test "zig fmt: add comma on last switch prong" {
+    try testTransform(
+        \\test "aoeu" {
+        \\switch (self.init_arg_expr) {
+        \\    InitArg.Type => |t| { },
+        \\    InitArg.None,
+        \\    InitArg.Enum => { }
+        \\}
+        \\ switch (self.init_arg_expr) {
+        \\     InitArg.Type => |t| { },
+        \\     InitArg.None,
+        \\     InitArg.Enum => { }//line comment
+        \\ }
+        \\}
+    ,
+        \\test "aoeu" {
+        \\    switch (self.init_arg_expr) {
+        \\        InitArg.Type => |t| {},
+        \\        InitArg.None,
+        \\        InitArg.Enum => {},
+        \\    }
+        \\    switch (self.init_arg_expr) {
+        \\        InitArg.Type => |t| {},
+        \\        InitArg.None,
+        \\        InitArg.Enum => {}, //line comment
+        \\    }
+        \\}
+        \\
+    );
+}
+
 test "zig fmt: same-line doc comment on variable declaration" {
     try testTransform(
         \\pub const MAP_ANONYMOUS = 0x1000; /// allocated from memory, swap space

@@ -831,7 +831,20 @@ fn renderExpression(allocator: &mem.Allocator, stream: var, tree: &ast.Tree, ind
             }
 
             try renderExpression(allocator, stream, tree, indent, switch_case.expr);
-            try renderToken(tree, stream, switch_case.lastToken() + 1, indent, true);
+            {
+                // Handle missing comma after last switch case
+                var index = switch_case.lastToken() + 1;
+                switch (tree.tokens.at(index).id) {
+                    Token.Id.RBrace => {
+                        try stream.write(",");
+                    },
+                    Token.Id.LineComment => {
+                        try stream.write(", ");
+                        try renderToken(tree, stream, index, indent, true);
+                    },
+                    else => try renderToken(tree, stream, index, indent, true),
+                }
+            }
         },
         ast.Node.Id.SwitchElse => {
             const switch_else = @fieldParentPtr(ast.Node.SwitchElse, "base", base);