Fix not applicable on trailing comma for remove_dbg

`remove_dbg` not applicable for whitespaces after trailing comma

Example
---
```rust
fn foo() {
    dbg!(
        bar(),
    );
}
```

**Before this PR**:

Assist not applicable

**After this PR**:

```rust
fn foo() {
    bar();
}
```

1 files changed, 16 insertions, 1 deletions

diff --git a/src/tools/rust-analyzer/crates/ide-assists/src/handlers/remove_dbg.rs b/src/tools/rust-analyzer/crates/ide-assists/src/handlers/remove_dbg.rs
index 414f6746d44..08779a3ed1f 100644
--- a/src/tools/rust-analyzer/crates/ide-assists/src/handlers/remove_dbg.rs
+++ b/src/tools/rust-analyzer/crates/ide-assists/src/handlers/remove_dbg.rs
@@ -83,7 +83,9 @@ fn compute_dbg_replacement(
     let input_expressions = input_expressions
         .into_iter()
         .filter_map(|(is_sep, group)| (!is_sep).then_some(group))
-        .map(|mut tokens| syntax::hacks::parse_expr_from_str(&tokens.join(""), Edition::CURRENT))
+        .map(|tokens| tokens.collect::<Vec<_>>())
+        .filter(|tokens| !tokens.iter().all(|it| it.kind().is_trivia()))
+        .map(|tokens| syntax::hacks::parse_expr_from_str(&tokens.iter().join(""), Edition::CURRENT))
         .collect::<Option<Vec<ast::Expr>>>()?;
 
     let parent = macro_expr.syntax().parent()?;
@@ -268,6 +270,8 @@ fn foo() {
     dbg!('x');
     dbg!(&n);
     dbg!(n);
+    dbg!(n,);
+    dbg!(n, );
     // needless comment
     dbg!("foo");$0
 }
@@ -282,6 +286,17 @@ fn foo() {
     }
 
     #[test]
+    fn test_remove_trailing_comma_dbg() {
+        check("$0dbg!(1 + 1,)", "1 + 1");
+        check("$0dbg!(1 + 1, )", "1 + 1");
+        check("$0dbg!(1 + 1,\n)", "1 + 1");
+        check("$0dbg!(1 + 1, 2 + 3)", "(1 + 1, 2 + 3)");
+        check("$0dbg!(1 + 1, 2 + 3 )", "(1 + 1, 2 + 3)");
+        check("$0dbg!(1 + 1, 2 + 3, )", "(1 + 1, 2 + 3)");
+        check("$0dbg!(1 + 1, 2 + 3 ,)", "(1 + 1, 2 + 3)");
+    }
+
+    #[test]
     fn test_remove_dbg_not_applicable() {
         check_assist_not_applicable(remove_dbg, "fn main() {$0vec![1, 2, 3]}");
         check_assist_not_applicable(remove_dbg, "fn main() {$0dbg(5, 6, 7)}");