Don't add space when joining line to opening quote

crates/ide/src/join_lines.rs

@@ -7,6 +7,7 @@ use syntax::{
     SyntaxKind::{self, USE_TREE, WHITESPACE},
     SyntaxNode, SyntaxToken, TextRange, TextSize, T,
 };
+use test_utils::mark;
 use text_edit::{TextEdit, TextEditBuilder};
 
 // Feature: Join Lines
@@ -44,9 +45,9 @@ pub(crate) fn join_lines(file: &SourceFile, range: TextRange) -> TextEdit {
         let text = token.text();
         for (pos, _) in text[range].bytes().enumerate().filter(|&(_, b)| b == b'\n') {
             let pos: TextSize = (pos as u32).into();
-            let off = token.text_range().start() + range.start() + pos;
+            let offset = token.text_range().start() + range.start() + pos;
-            if !edit.invalidates_offset(off) {
+            if !edit.invalidates_offset(offset) {
-                remove_newline(&mut edit, &token, off);
+                remove_newline(&mut edit, &token, offset);
             }
         }
     }
@@ -56,14 +57,25 @@ pub(crate) fn join_lines(file: &SourceFile, range: TextRange) -> TextEdit {
 
 fn remove_newline(edit: &mut TextEditBuilder, token: &SyntaxToken, offset: TextSize) {
     if token.kind() != WHITESPACE || token.text().bytes().filter(|&b| b == b'\n').count() != 1 {
-        // The node is either the first or the last in the file
+        let mut string_open_quote = false;
-        let suff = &token.text()[TextRange::new(
+        if let Some(string) = ast::String::cast(token.clone()) {
-            offset - token.text_range().start() + TextSize::of('\n'),
+            if let Some(range) = string.open_quote_text_range() {
-            TextSize::of(token.text()),
+                mark::hit!(join_string_literal);
-        )];
+                string_open_quote = range.end() == offset;
-        let spaces = suff.bytes().take_while(|&b| b == b' ').count();
+            }
+        }
 
-        edit.replace(TextRange::at(offset, ((spaces + 1) as u32).into()), " ".to_string());
+        let n_spaces_after_line_break = {
+            let suff = &token.text()[TextRange::new(
+                offset - token.text_range().start() + TextSize::of('\n'),
+                TextSize::of(token.text()),
+            )];
+            suff.bytes().take_while(|&b| b == b' ').count()
+        };
+
+        let range = TextRange::at(offset, ((n_spaces_after_line_break + 1) as u32).into());
+        let replace_with = if string_open_quote { "" } else { " " };
+        edit.replace(range, replace_with.to_string());
         return;
     }
 
@@ -194,7 +206,7 @@ fn compute_ws(left: SyntaxKind, right: SyntaxKind) -> &'static str {
 #[cfg(test)]
 mod tests {
     use syntax::SourceFile;
-    use test_utils::{add_cursor, assert_eq_text, extract_offset, extract_range};
+    use test_utils::{add_cursor, assert_eq_text, extract_offset, extract_range, mark};
 
     use super::*;
 
@@ -771,4 +783,42 @@ fn foo() {
         ",
         );
     }
+
+    #[test]
+    fn join_string_literal() {
+        mark::check!(join_string_literal);
+        check_join_lines(
+            r#"
+fn main() {
+    $0"
+hello
+";
+}
+"#,
+            r#"
+fn main() {
+    $0"hello
+";
+}
+"#,
+        );
+
+        check_join_lines(
+            r#"
+fn main() {
+    "
+$0hello
+world
+";
+}
+"#,
+            r#"
+fn main() {
+    "
+$0hello world
+";
+}
+"#,
+        );
+    }
 }