Check for comment before Ident and related changes to tests

Author: davidBar-On

src/formatting/items.rs

@@ -1136,6 +1136,12 @@ pub(crate) fn format_trait(
         );
         result.push_str(&header);
 
+        // FIXME: rustfmt fails to format when there are comments between `trait` and ident.
+        let trait_hi = context.snippet_provider.span_after(item.span, "trait");
+        if contains_comment(context.snippet(mk_sp(trait_hi, generics.span.lo()))) {
+            return None;
+        }
+
         let body_lo = context.snippet_provider.span_after(item.span, "{");
 
         let shape = Shape::indented(offset, context.config).offset_left(result.len())?;

tests/source/lhs-to-rhs-bewteen-comments/trait.rs

@@ -36,17 +36,32 @@ fn university(&self) -> String;
 trait Programmer/* comment1 */{
 fn fav_language(&self) -> String;
 }
-trait/* comment1 */CompSciStudent1:/* comment2 */Programmer + Student/* comment3 */{
+trait CompSciStudent1:/* comment1 */Programmer + Student/* comment2 */{
 fn git_username(&self) -> String;
 }
-trait/* comment1 */CompSciStudent2:/* comment2 Longggggggggggggggggggggggggggggggggggggggggggggggggg */Programmer + Student/* comment3 */{
+trait CompSciStudent2:/* comment1 Longggggggggggggggggggggggggggggggggggggggggggggggggg */Programmer + Student/* comment2 */{
 fn git_username(&self) -> String;
 }
-trait/* comment1 */CompSciStudent3:// comment2
-Programmer + Student/* comment3 */{
+trait CompSciStudent3:// comment1
+Programmer + Student/* comment2 */{
 fn git_username(&self) -> String;
 }
-trait/* comment1 */CompSciStudent4:// comment2 Longgggggggggggggggggggggggggggggggggggggggggggggggggg
-Programmer + Student/* comment3 */{
+trait CompSciStudent4:// comment1 Longgggggggggggggggggggggggggggggggggggggggggggggggggg
+Programmer + Student/* comment2 */{
 fn git_username(&self) -> String;
 }
+
+// Comment before Ident
+trait /* comment1 */ Person {
+    fn fav_language(&self) -> String;
+}
+trait // comment1
+Person {
+    fn fav_language(&self) -> String;
+}
+trait /* comment 1 */ Programmer /* comment2 */ {
+    fn fav_language(&self) -> String;
+}
+trait /* comment1 */ CompSciStudent1: /* comment2 */ Programmer + Student /* comment3 */ {
+    fn git_username(&self) -> String;
+}

tests/target/lhs-to-rhs-bewteen-comments/trait.rs

@@ -30,22 +30,37 @@ trait Student: /* comment1 */ Person /* comment2 */ {
 trait Programmer /* comment1 */ {
     fn fav_language(&self) -> String;
 }
-trait CompSciStudent1: /* comment2 */ Programmer + Student /* comment3 */ {
+trait CompSciStudent1: /* comment1 */ Programmer + Student /* comment2 */ {
     fn git_username(&self) -> String;
 }
 trait CompSciStudent2:
-    /* comment2 Longggggggggggggggggggggggggggggggggggggggggggggggggg */
-    Programmer + Student /* comment3 */
+    /* comment1 Longggggggggggggggggggggggggggggggggggggggggggggggggg */
+    Programmer + Student /* comment2 */
 {
     fn git_username(&self) -> String;
 }
-trait CompSciStudent3: // comment2
-    Programmer + Student /* comment3 */
+trait CompSciStudent3: // comment1
+    Programmer + Student /* comment2 */
 {
     fn git_username(&self) -> String;
 }
-trait CompSciStudent4: // comment2 Longgggggggggggggggggggggggggggggggggggggggggggggggggg
-    Programmer + Student /* comment3 */
+trait CompSciStudent4: // comment1 Longgggggggggggggggggggggggggggggggggggggggggggggggggg
+    Programmer + Student /* comment2 */
 {
     fn git_username(&self) -> String;
 }
+
+// Comment before Ident
+trait /* comment1 */ Person {
+    fn fav_language(&self) -> String;
+}
+trait // comment1
+Person {
+    fn fav_language(&self) -> String;
+}
+trait /* comment 1 */ Programmer /* comment2 */ {
+    fn fav_language(&self) -> String;
+}
+trait /* comment1 */ CompSciStudent1: /* comment2 */ Programmer + Student /* comment3 */ {
+    fn git_username(&self) -> String;
+}