From 965d151168f3c58c4463ea4fd1eaf220f108c694 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?S=C3=A9bastien=20Besnier?=
 <sebastien.fabrice.besnier@gmail.com>
Date: Mon, 28 Dec 2020 18:57:45 +0100
Subject: [PATCH] add tag union tests for trailing commas formatting

---
 compiler/fmt/src/expr.rs       |  2 +-
 compiler/fmt/tests/test_fmt.rs | 62 ++++++++++++++++++++++++++--------
 2 files changed, 48 insertions(+), 16 deletions(-)

diff --git a/compiler/fmt/src/expr.rs b/compiler/fmt/src/expr.rs
index 623326ac19..1be56ee514 100644
--- a/compiler/fmt/src/expr.rs
+++ b/compiler/fmt/src/expr.rs
@@ -415,7 +415,7 @@ pub fn fmt_list<'a>(
             for item in loc_items.iter() {
                 match &item.value {
                     // TODO?? These SpaceAfter/SpaceBefore litany seems overcomplicated
-                    // Can we simplify this?
+                    // Can we simplify this? Or at least move this in a separate function.
                     Expr::SpaceBefore(expr_below, spaces_above_expr) => {
                         newline(buf, item_indent);
                         fmt_comments_only(
diff --git a/compiler/fmt/tests/test_fmt.rs b/compiler/fmt/tests/test_fmt.rs
index 8b7004fbcb..adcbfd46b7 100644
--- a/compiler/fmt/tests/test_fmt.rs
+++ b/compiler/fmt/tests/test_fmt.rs
@@ -2452,22 +2452,54 @@ mod test_fmt {
         ));
     }
 
-    // TODO This raises a parse error:
-    // NotYetImplemented("TODO the : in this declaration seems outdented")
-    // #[test]
-    // fn multiline_tag_union_annotation() {
-    //     expr_formats_same(indoc!(
-    //         r#"
-    //         b :
-    //             [
-    //                 True,
-    //                 False,
-    //             ]
+    #[test]
+    fn multiline_tag_union_annotation() {
+        expr_formats_same(indoc!(
+            r#"
+            b :
+                [
+                    True,
+                    False,
+                ]
 
-    //         b
-    //         "#
-    //     ));
-    // }
+            b
+            "#
+        ));
+    }
+
+    #[test]
+    fn multiline_tag_union_annotation_with_final_comment() {
+        expr_formats_to(
+            indoc!(
+                r#"
+            b :
+                [
+                    True,
+                    # comment 1
+                    False # comment 2
+                    ,
+                    # comment 3
+                ]
+
+            b
+            "#
+            ),
+            indoc!(
+                r#"
+                b :
+                    [
+                        True,
+                        # comment 1
+                        False,
+                        # comment 2
+                        # comment 3
+                    ]
+    
+                b
+                "#
+            ),
+        );
+    }
 
     #[test]
     fn tag_union() {