Add overflow_closures and overflow_match_arms opts

Configurations.md

@@ -1265,6 +1265,64 @@ Maximum width of each line
 
 See also [`error_on_line_overflow`](#error_on_line_overflow).
 
+## `multiline_closure_forces_block`
+
+Force multiline closure bodies to be wrapped in a block
+
+- **Default value**: `false`
+- **Possible values**: `false`, `true`
+
+#### `false`:
+
+```rust
+result.and_then(|maybe_value| match maybe_value {
+ None => ...,
+ Some(value) => ...,
+})
+```
+
+#### `true`:
+
+```rust
+result.and_then(|maybe_value| {
+ match maybe_value {
+ None => ...,
+ Some(value) => ...,
+ }
+})
+```
+
+## `multiline_match_arm_forces_block`
+
+Force multiline match arm bodies to be wrapped in a block
+
+- **Default value**: `false`
+- **Possible values**: `false`, `true`
+
+#### `false`:
+
+```rust
+match lorem {
+ None => if ipsum {
+ println!("Hello World");
+ },
+ Some(dolor) => ...,
+}
+```
+
+#### `true`:
+
+```rust
+match lorem {
+ None => {
+ if ipsum {
+ println!("Hello World");
+ }
+ }
+ Some(dolor) => ...,
+}
+```
+
 ## `newline_style`
 
 Unix or Windows line endings

src/config.rs

@@ -615,6 +615,10 @@ create_config! {
  "Try to put attributes on the same line as fields.";
  attributes_on_same_line_as_variant: bool, true,
  "Try to put attributes on the same line as variants in enum declarations.";
+ multiline_closure_forces_block: bool, false,
+ "Force multiline closure bodies to be wrapped in a block";
+ multiline_match_arm_forces_block: bool, false,
+ "Force multiline match arm bodies to be wrapped in a block";
 }
 
 #[cfg(test)]

src/expr.rs

@@ -690,6 +690,13 @@ fn rewrite_closure_expr(
  if classify::expr_requires_semi_to_be_stmt(left_most_sub_expr(expr)) {
  rewrite = and_one_line(rewrite);
  }
+ rewrite = rewrite.and_then(|rw| {
+ if context.config.multiline_closure_forces_block() && rw.contains('\n') {
+ None
+ } else {
+ Some(rw)
+ }
+ });
  rewrite.map(|rw| format!("{} {}", prefix, rw))
 }
 
@@ -1690,12 +1697,20 @@ fn flatten_arm_body<'a>(context: &'a RewriteContext, body: &'a ast::Expr) -> (bo
  if !is_unsafe_block(block) && is_simple_block(block, context.codemap) =>
  {
  if let ast::StmtKind::Expr(ref expr) = block.stmts[0].node {
- (expr.can_be_overflowed(context, 1), &**expr)
+ (
+ !context.config.multiline_match_arm_forces_block() &&
+ expr.can_be_overflowed(context, 1),
+ &**expr,
+ )
  } else {
  (false, &*body)
  }
  }
- _ => (body.can_be_overflowed(context, 1), &*body),
+ _ => (
+ !context.config.multiline_match_arm_forces_block() &&
+ body.can_be_overflowed(context, 1),
+ &*body,
+ ),
  }
 }
 

tests/source/configs-multiline_closure_forces_block-false.rs

@@ -0,0 +1,11 @@
+// rustfmt-multiline_closure_forces_block: false
+// Option forces multiline closure bodies to be wrapped in a block
+
+fn main() {
+ result.and_then(|maybe_value| {
+ match maybe_value {
+ None => Err("oops"),
+ Some(value) => Ok(1),
+ }
+ });
+}

tests/source/configs-multiline_closure_forces_block-true.rs

@@ -0,0 +1,9 @@
+// rustfmt-multiline_closure_forces_block: true
+// Option forces multiline closure bodies to be wrapped in a block
+
+fn main() {
+ result.and_then(|maybe_value| match maybe_value {
+ None => Err("oops"),
+ Some(value) => Ok(1),
+ });
+}

tests/source/configs-multiline_match_arm_forces_block-false.rs

@@ -0,0 +1,13 @@
+// rustfmt-multiline_match_arm_forces_block: false
+// Option forces multiline match arm bodies to be wrapped in a block
+
+fn main() {
+ match lorem {
+ Lorem::Ipsum => {
+ if ipsum {
+ println!("dolor");
+ }
+ }
+ Lorem::Dolor => println!("amet"),
+ }
+}

tests/source/configs-multiline_match_arm_forces_block-true.rs

@@ -0,0 +1,11 @@
+// rustfmt-multiline_match_arm_forces_block: true
+// Option forces multiline match arm bodies to be wrapped in a block
+
+fn main() {
+ match lorem {
+ Lorem::Ipsum => if ipsum {
+ println!("dolor");
+ },
+ Lorem::Dolor => println!("amet"),
+ }
+}

tests/target/configs-multiline_closure_forces_block-false.rs

@@ -0,0 +1,9 @@
+// rustfmt-multiline_closure_forces_block: false
+// Option forces multiline closure bodies to be wrapped in a block
+
+fn main() {
+ result.and_then(|maybe_value| match maybe_value {
+ None => Err("oops"),
+ Some(value) => Ok(1),
+ });
+}

tests/target/configs-multiline_closure_forces_block-true.rs

@@ -0,0 +1,11 @@
+// rustfmt-multiline_closure_forces_block: true
+// Option forces multiline closure bodies to be wrapped in a block
+
+fn main() {
+ result.and_then(|maybe_value| {
+ match maybe_value {
+ None => Err("oops"),
+ Some(value) => Ok(1),
+ }
+ });
+}

tests/target/configs-multiline_match_arm_forces_block-false.rs

@@ -0,0 +1,11 @@
+// rustfmt-multiline_match_arm_forces_block: false
+// Option forces multiline match arm bodies to be wrapped in a block
+
+fn main() {
+ match lorem {
+ Lorem::Ipsum => if ipsum {
+ println!("dolor");
+ },
+ Lorem::Dolor => println!("amet"),
+ }
+}

tests/target/configs-multiline_match_arm_forces_block-true.rs

@@ -0,0 +1,13 @@
+// rustfmt-multiline_match_arm_forces_block: true
+// Option forces multiline match arm bodies to be wrapped in a block
+
+fn main() {
+ match lorem {
+ Lorem::Ipsum => {
+ if ipsum {
+ println!("dolor");
+ }
+ }
+ Lorem::Dolor => println!("amet"),
+ }
+}