fix: join lines doesn't add space before closing quote

Author: matklad

crates/ide/src/join_lines.rs

@@ -1,3 +1,5 @@
+use std::convert::TryFrom;
+
 use ide_assists::utils::extract_trivial_expression;
 use itertools::Itertools;
 use syntax::{
@@ -85,6 +87,21 @@ fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextS
             suff.bytes().take_while(|&b| b == b' ').count()
         };
 
+        let mut no_space = false;
+        if let Some(string) = ast::String::cast(token.clone()) {
+            if let Some(range) = string.open_quote_text_range() {
+                cov_mark::hit!(join_string_literal_open_quote);
+                no_space |= range.end() == offset;
+            }
+            if let Some(range) = string.close_quote_text_range() {
+                cov_mark::hit!(join_string_literal_close_quote);
+                no_space |= range.start()
+                    == offset
+                        + TextSize::of('\n')
+                        + TextSize::try_from(n_spaces_after_line_break).unwrap();
+            }
+        }
+
         let range = TextRange::at(offset, ((n_spaces_after_line_break + 1) as u32).into());
         let replace_with = if no_space { "" } else { " " };
         edit.replace(range, replace_with.to_string());
@@ -833,6 +850,19 @@ fn main() {
 fn main() {
     $0"hello";
 }
+"#,
+            );
+            check_join_lines(
+                r#"
+fn main() {
+    $0r"hello
+    ";
+}
+"#,
+                r#"
+fn main() {
+    $0r"hello";
+}
 "#,
             );
         }