diff --git a/Configurations.md b/Configurations.md
index 58d7aac52ef..10fed5b4c1e 100644
--- a/Configurations.md
+++ b/Configurations.md
@@ -180,6 +180,56 @@ fn bar() {
See also: [`blank_lines_lower_bound`](#blank_lines_lower_bound)
+
+## `indent_blank_lines`
+
+Empty lines are indented like items in the same block.
+
+- **Default value**: `false`
+- **Possible values**: `true`, `false`
+- **Stable**: No (tracking issue: TBD)
+
+### Example
+
+#### `false` (default):
+```rust
+fn foo() {
+ println!("a");
+
+ if true {
+ println!("b");
+
+ let Some(x) = Some(x) else {
+ println!("c");
+
+ println!("d");
+ };
+
+ println!("e");
+ }
+}
+```
+
+#### `true`:
+```rust
+fn foo() {
+ println!("a");
+
+ if true {
+ println!("b");
+
+ let Some(x) = Some(x) else {
+ println!("c");
+
+ println!("d");
+ };
+
+ println!("e");
+ }
+}
+```
+
+
## `brace_style`
Brace style for items
diff --git a/src/config/mod.rs b/src/config/mod.rs
index b03674b6b3c..5f5cd24fbef 100644
--- a/src/config/mod.rs
+++ b/src/config/mod.rs
@@ -152,6 +152,8 @@ create_config! {
"Maximum number of blank lines which can be put between items";
blank_lines_lower_bound: BlankLinesLowerBound, false,
"Minimum number of blank lines which must be put between items";
+ indent_blank_lines: IndentBlankLines, false,
+ "Indent blank lines";
edition: EditionConfig, true, "The edition of the parser (RFC 2052)";
style_edition: StyleEditionConfig, true, "The edition of the Style Guide (RFC 3338)";
version: VersionConfig, false, "Version of formatting rules";
@@ -815,6 +817,7 @@ trailing_comma = "Vertical"
match_block_trailing_comma = false
blank_lines_upper_bound = 1
blank_lines_lower_bound = 0
+indent_blank_lines = false
edition = "2015"
style_edition = "2015"
version = "One"
@@ -907,6 +910,7 @@ trailing_comma = "Vertical"
match_block_trailing_comma = false
blank_lines_upper_bound = 1
blank_lines_lower_bound = 0
+indent_blank_lines = false
edition = "2015"
style_edition = "2024"
version = "Two"
diff --git a/src/config/options.rs b/src/config/options.rs
index 00f9c3f7ec1..69a3c8b8ff7 100644
--- a/src/config/options.rs
+++ b/src/config/options.rs
@@ -676,6 +676,7 @@ config_option_with_style_edition_default!(
MatchBlockTrailingComma, bool, _ => false;
BlankLinesUpperBound, usize, _ => 1;
BlankLinesLowerBound, usize, _ => 0;
+ IndentBlankLines, bool, _ => false;
EditionConfig, Edition, _ => Edition::Edition2015;
StyleEditionConfig, StyleEdition,
Edition2024 => StyleEdition::Edition2024, _ => StyleEdition::Edition2015;
diff --git a/src/formatting.rs b/src/formatting.rs
index 1e1e329f624..4edae7ca17b 100644
--- a/src/formatting.rs
+++ b/src/formatting.rs
@@ -494,6 +494,7 @@ struct FormatLines<'a> {
name: &'a FileName,
skipped_range: &'a [(usize, usize)],
last_was_space: bool,
+ line_all_space: bool,
line_len: usize,
cur_line: usize,
newline_count: usize,
@@ -514,6 +515,7 @@ impl<'a> FormatLines<'a> {
name,
skipped_range,
last_was_space: false,
+ line_all_space: true,
line_len: 0,
cur_line: 1,
newline_count: 0,
@@ -546,6 +548,7 @@ impl<'a> FormatLines<'a> {
if self.last_was_space {
if self.should_report_error(kind, &ErrorKind::TrailingWhitespace)
&& !self.is_skipped_line()
+ && !(self.line_all_space && self.config.indent_blank_lines())
{
self.push_err(
ErrorKind::TrailingWhitespace,
@@ -575,6 +578,7 @@ impl<'a> FormatLines<'a> {
.contains_line(self.name, self.cur_line);
self.newline_count += 1;
self.last_was_space = false;
+ self.line_all_space = true;
self.line_buffer.clear();
self.current_line_contains_string_literal = false;
}
@@ -587,6 +591,7 @@ impl<'a> FormatLines<'a> {
1
};
self.last_was_space = c.is_whitespace();
+ self.line_all_space &= self.last_was_space;
self.line_buffer.push(c);
if kind.is_string() {
self.current_line_contains_string_literal = true;
diff --git a/src/missed_spans.rs b/src/missed_spans.rs
index 384de1ce9ae..ce01b9d6ed2 100644
--- a/src/missed_spans.rs
+++ b/src/missed_spans.rs
@@ -114,25 +114,36 @@ impl<'a> FmtVisitor<'a> {
}
fn push_vertical_spaces(&mut self, mut newline_count: usize) {
- let offset = self.buffer.chars().rev().take_while(|c| *c == '\n').count();
- let newline_upper_bound = self.config.blank_lines_upper_bound() + 1;
- let newline_lower_bound = self.config.blank_lines_lower_bound() + 1;
-
- if newline_count + offset > newline_upper_bound {
- if offset >= newline_upper_bound {
- newline_count = 0;
- } else {
- newline_count = newline_upper_bound - offset;
- }
- } else if newline_count + offset < newline_lower_bound {
- if offset >= newline_lower_bound {
- newline_count = 0;
- } else {
- newline_count = newline_lower_bound - offset;
- }
+ if let [] | [.., b'\n'] = self.buffer.as_bytes() {
+ /* Already at the start of a new line */
+ } else {
+ self.push_str("\n");
+ newline_count = newline_count.saturating_sub(1);
}
- let blank_lines = "\n".repeat(newline_count);
+ let indent = if self.config.indent_blank_lines() {
+ // FIXME: Should this include the alignment as well?
+ &*self.block_indent.block_only().to_string(self.config)
+ } else {
+ ""
+ };
+
+ let existing_blanks = self
+ .buffer
+ .rsplit_terminator('\n')
+ .take_while(|&line| line == indent)
+ .count();
+
+ // Clamp new total count to configuration.
+ let total = (existing_blanks + newline_count).clamp(
+ self.config.blank_lines_lower_bound(),
+ self.config.blank_lines_upper_bound(),
+ );
+
+ let blank_lines = std::iter::repeat(indent)
+ .take(total.saturating_sub(existing_blanks))
+ .fold(String::new(), |s, indent| s + indent + "\n");
+
self.push_str(&blank_lines);
}
diff --git a/tests/source/configs/indent_blank_lines/true.rs b/tests/source/configs/indent_blank_lines/true.rs
new file mode 100644
index 00000000000..91aa11708d6
--- /dev/null
+++ b/tests/source/configs/indent_blank_lines/true.rs
@@ -0,0 +1,40 @@
+// rustfmt-indent_blank_lines: true
+
+fn foo() {
+ if true {
+ println!("a");
+
+ match 4 {
+ 0 => {
+ println!("b");
+
+ println!("c");
+ // FIXME: empty lines between match arms currently ignore this configuration:
+ }
+
+ x => {
+ x = x
+ .wrapping_add({
+ // inner block
+ let a = 4;
+
+ a + 5
+ })
+ .unwrap();
+
+ if x > 10 {
+ println!("{x}");
+
+ println!("{x}");
+ }
+ }
+ }
+ }
+}
+
+fn bar()
+where
+ u32: Sized, // FIXME: empty lines between where bounds ignores it
+
+ i32: Sized,
+{}
\ No newline at end of file
diff --git a/tests/target/configs/indent_blank_lines/true.rs b/tests/target/configs/indent_blank_lines/true.rs
new file mode 100644
index 00000000000..614b956f0a4
--- /dev/null
+++ b/tests/target/configs/indent_blank_lines/true.rs
@@ -0,0 +1,41 @@
+// rustfmt-indent_blank_lines: true
+
+fn foo() {
+ if true {
+ println!("a");
+
+ match 4 {
+ 0 => {
+ println!("b");
+
+ println!("c");
+ // FIXME: empty lines between match arms currently ignore this configuration:
+ }
+
+ x => {
+ x = x
+ .wrapping_add({
+ // inner block
+ let a = 4;
+
+ a + 5
+ })
+ .unwrap();
+
+ if x > 10 {
+ println!("{x}");
+
+ println!("{x}");
+ }
+ }
+ }
+ }
+}
+
+fn bar()
+where
+ u32: Sized, // FIXME: empty lines between where bounds ignores it
+
+ i32: Sized,
+{
+}