Remove rest of line in unused_import if there is nothing else

Author: clubby789

compiler/rustc_resolve/src/check_unused.rs

@@ -373,7 +373,14 @@ impl Resolver<'_, '_> {
                 }
             );
 
-            let fix_msg = if fixes.len() == 1 && fixes[0].0 == unused.item_span {
+            let fix_msg = if let [(sp, _)] = fixes.as_mut_slice()
+                && *sp == unused.item_span
+            {
+                // If this is the only import on the line, remove the whole line
+                if let Ok(next) = tcx.sess.source_map().span_to_next_source(*sp) {
+                    let whitespace = next.chars().take_while(char::is_ascii_whitespace).count();
+                    *sp = sp.with_hi(sp.hi() + rustc_span::BytePos(whitespace as u32));
+                }
                 "remove the whole `use` item"
             } else if ms.primary_spans().len() > 1 {
                 "remove the unused imports"

tests/ui/imports/unused-import-issue-87973.fixed

@@ -2,7 +2,6 @@
 #![deny(unused_imports)]
 
 // Check that attributes get removed too. See #87973.
-
 //~^ ERROR unused import
 
 fn main() {}

tests/ui/lint/unused/import_remove_line.fixed

@@ -0,0 +1,10 @@
+// run-rustfix
+// check-pass
+
+#![crate_type = "lib"]
+#![warn(unused_imports)]
+
+//~^ WARN unused imports
+//~^ WARN unused import
+//~^ WARN unused import
+//~| WARN unused import

tests/ui/lint/unused/import_remove_line.rs

@@ -0,0 +1,13 @@
+// run-rustfix
+// check-pass
+
+#![crate_type = "lib"]
+#![warn(unused_imports)]
+
+use std::time::{Duration, Instant};
+//~^ WARN unused imports
+use std::time::SystemTime;
+//~^ WARN unused import
+use std::time::SystemTimeError;use std::time::TryFromFloatSecsError;
+//~^ WARN unused import
+//~| WARN unused import

tests/ui/lint/unused/import_remove_line.stderr

@@ -0,0 +1,32 @@
+warning: unused imports: `Duration`, `Instant`
+  --> $DIR/import_remove_line.rs:7:17
+   |
+LL | use std::time::{Duration, Instant};
+   |                 ^^^^^^^^  ^^^^^^^
+   |
+note: the lint level is defined here
+  --> $DIR/import_remove_line.rs:5:9
+   |
+LL | #![warn(unused_imports)]
+   |         ^^^^^^^^^^^^^^
+
+warning: unused import: `std::time::SystemTime`
+  --> $DIR/import_remove_line.rs:9:5
+   |
+LL | use std::time::SystemTime;
+   |     ^^^^^^^^^^^^^^^^^^^^^
+
+warning: unused import: `std::time::SystemTimeError`
+  --> $DIR/import_remove_line.rs:11:5
+   |
+LL | use std::time::SystemTimeError;use std::time::TryFromFloatSecsError;
+   |     ^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: unused import: `std::time::TryFromFloatSecsError`
+  --> $DIR/import_remove_line.rs:11:36
+   |
+LL | use std::time::SystemTimeError;use std::time::TryFromFloatSecsError;
+   |                                    ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
+
+warning: 4 warnings emitted
+