Fix postfix completion indentation compensation

crates/ide-completion/src/completions/postfix.rs

@@ -355,12 +355,20 @@ fn get_receiver_text(
         range.range = TextRange::at(range.range.start(), range.range.len() - TextSize::of('.'))
     }
     let file_text = sema.db.file_text(range.file_id.file_id(sema.db));
-    let mut text = file_text.text(sema.db)[range.range].to_owned();
+    let text = file_text.text(sema.db);
+    let indent_spaces = indent_of_tail_line(&text[TextRange::up_to(range.range.start())]);
+    let mut text = stdx::dedent_by(indent_spaces, &text[range.range]);
 
     // The receiver texts should be interpreted as-is, as they are expected to be
     // normal Rust expressions.
     escape_snippet_bits(&mut text);
-    text
+    return text;
+
+    fn indent_of_tail_line(text: &str) -> usize {
+        let tail_line = text.rsplit_once('\n').map_or(text, |(_, s)| s);
+        let trimmed = tail_line.trim_start_matches(' ');
+        tail_line.len() - trimmed.len()
+    }
 }
 
 /// Escapes `\` and `$` so that they don't get interpreted as snippet-specific constructs.
@@ -977,9 +985,9 @@ use core::ops::ControlFlow;
 
 fn main() {
     ControlFlow::Break(match true {
-        true => "\${1:placeholder}",
-        false => "\\\$",
-    })
+    true => "\${1:placeholder}",
+    false => "\\\$",
+})
 }
 "#,
         );
@@ -1219,4 +1227,31 @@ fn foo() {
         "#,
         );
     }
+
+    #[test]
+    fn snippet_dedent() {
+        check_edit(
+            "let",
+            r#"
+//- minicore: option
+fn foo(x: Option<i32>, y: Option<i32>) {
+    let _f = || {
+        x
+            .and(y)
+            .map(|it| it+2)
+            .$0
+    };
+}
+"#,
+            r#"
+fn foo(x: Option<i32>, y: Option<i32>) {
+    let _f = || {
+        let $0 = x
+    .and(y)
+    .map(|it| it+2);
+    };
+}
+"#,
+        );
+    }
 }

crates/stdx/src/lib.rs

@@ -207,12 +207,7 @@ pub fn trim_indent(mut text: &str) -> String {
     if text.starts_with('\n') {
         text = &text[1..];
     }
-    let indent = text
-        .lines()
-        .filter(|it| !it.trim().is_empty())
-        .map(|it| it.len() - it.trim_start().len())
-        .min()
-        .unwrap_or(0);
+    let indent = indent_of(text);
     text.split_inclusive('\n')
         .map(
             |line| {
@@ -222,6 +217,25 @@ pub fn trim_indent(mut text: &str) -> String {
         .collect()
 }
 
+#[must_use]
+fn indent_of(text: &str) -> usize {
+    text.lines()
+        .filter(|it| !it.trim().is_empty())
+        .map(|it| it.len() - it.trim_start().len())
+        .min()
+        .unwrap_or(0)
+}
+
+#[must_use]
+pub fn dedent_by(spaces: usize, text: &str) -> String {
+    text.split_inclusive('\n')
+        .map(|line| {
+            let trimmed = line.trim_start_matches(' ');
+            if line.len() - trimmed.len() <= spaces { trimmed } else { &line[spaces..] }
+        })
+        .collect()
+}
+
 pub fn equal_range_by<T, F>(slice: &[T], mut key: F) -> ops::Range<usize>
 where
     F: FnMut(&T) -> Ordering,
@@ -352,6 +366,37 @@ mod tests {
         );
     }
 
+    #[test]
+    fn test_dedent() {
+        assert_eq!(dedent_by(0, ""), "");
+        assert_eq!(dedent_by(1, ""), "");
+        assert_eq!(dedent_by(2, ""), "");
+        assert_eq!(dedent_by(0, "foo"), "foo");
+        assert_eq!(dedent_by(2, "foo"), "foo");
+        assert_eq!(dedent_by(2, "  foo"), "foo");
+        assert_eq!(dedent_by(2, "    foo"), "  foo");
+        assert_eq!(dedent_by(2, "    foo\nbar"), "  foo\nbar");
+        assert_eq!(dedent_by(2, "foo\n    bar"), "foo\n  bar");
+        assert_eq!(dedent_by(2, "foo\n\n    bar"), "foo\n\n  bar");
+        assert_eq!(dedent_by(2, "foo\n.\n    bar"), "foo\n.\n  bar");
+        assert_eq!(dedent_by(2, "foo\n .\n    bar"), "foo\n.\n  bar");
+        assert_eq!(dedent_by(2, "foo\n   .\n    bar"), "foo\n .\n  bar");
+    }
+
+    #[test]
+    fn test_indent_of() {
+        assert_eq!(indent_of(""), 0);
+        assert_eq!(indent_of(" "), 0);
+        assert_eq!(indent_of(" x"), 1);
+        assert_eq!(indent_of(" x\n"), 1);
+        assert_eq!(indent_of(" x\ny"), 0);
+        assert_eq!(indent_of(" x\n y"), 1);
+        assert_eq!(indent_of(" x\n  y"), 1);
+        assert_eq!(indent_of("  x\n  y"), 2);
+        assert_eq!(indent_of("  x\n  y\n"), 2);
+        assert_eq!(indent_of("  x\n\n  y\n"), 2);
+    }
+
     #[test]
     fn test_replace() {
         #[track_caller]