Merge pull request #1889 from topecongiro/match-arm

Do not put if on the same line as match arm

src/bin/cargo-fmt.rs

@@ -94,11 +94,13 @@ fn execute() -> i32 {
             print_usage_to_stderr(&opts, &e.to_string());
             failure
         }
-        Ok(status) => if status.success() {
-            success
-        } else {
-            status.code().unwrap_or(failure)
-        },
+        Ok(status) => {
+            if status.success() {
+                success
+            } else {
+                status.code().unwrap_or(failure)
+            }
+        }
     }
 }
 

src/config.rs

@@ -568,9 +568,11 @@ pub fn get_toml_path(dir: &Path) -> Result<Option<PathBuf>, Error> {
             Ok(ref md) if md.is_file() => return Ok(Some(config_file)),
             // Return the error if it's something other than `NotFound`; otherwise we didn't
             // find the project file yet, and continue searching.
-            Err(e) => if e.kind() != ErrorKind::NotFound {
-                return Err(e);
-            },
+            Err(e) => {
+                if e.kind() != ErrorKind::NotFound {
+                    return Err(e);
+                }
+            }
             _ => {}
         }
     }

src/expr.rs

@@ -462,18 +462,20 @@ where
                 None => DefinitiveListTactic::Vertical,
             }
         }
-        IndentStyle::Visual => if has_long_item || items.iter().any(ListItem::is_multiline) {
-            definitive_tactic(
-                &items,
-                ListTactic::LimitedHorizontalVertical(
-                    context.config.width_heuristics().array_width,
-                ),
-                Separator::Comma,
-                nested_shape.width,
-            )
-        } else {
-            DefinitiveListTactic::Mixed
-        },
+        IndentStyle::Visual => {
+            if has_long_item || items.iter().any(ListItem::is_multiline) {
+                definitive_tactic(
+                    &items,
+                    ListTactic::LimitedHorizontalVertical(
+                        context.config.width_heuristics().array_width,
+                    ),
+                    Separator::Comma,
+                    nested_shape.width,
+                )
+            } else {
+                DefinitiveListTactic::Mixed
+            }
+        }
     };
     let ends_with_newline = tactic.ends_with_newline(context.config.indent_style());
 
@@ -1500,8 +1502,8 @@ fn flatten_arm_body<'a>(context: &'a RewriteContext, body: &'a ast::Expr) -> (bo
         {
             if let ast::StmtKind::Expr(ref expr) = block.stmts[0].node {
                 (
-                    !context.config.force_multiline_blocks() && expr.can_be_overflowed(context, 1),
-                    &**expr,
+                    !context.config.force_multiline_blocks() && can_extend_match_arm_body(expr),
+                    &*expr,
                 )
             } else {
                 (false, &*body)
@@ -1723,6 +1725,33 @@ fn rewrite_pat_expr(
         .map(|expr_rw| format!("\n{}{}", nested_indent_str, expr_rw))
 }
 
+fn can_extend_match_arm_body(body: &ast::Expr) -> bool {
+    match body.node {
+        // We do not allow `if` to stay on the same line, since we could easily mistake
+        // `pat => if cond { ... }` and `pat if cond => { ... }`.
+        ast::ExprKind::If(..) | ast::ExprKind::IfLet(..) => false,
+        ast::ExprKind::ForLoop(..)
+        | ast::ExprKind::Loop(..)
+        | ast::ExprKind::While(..)
+        | ast::ExprKind::WhileLet(..)
+        | ast::ExprKind::Match(..)
+        | ast::ExprKind::Block(..)
+        | ast::ExprKind::Closure(..)
+        | ast::ExprKind::Array(..)
+        | ast::ExprKind::Call(..)
+        | ast::ExprKind::MethodCall(..)
+        | ast::ExprKind::Mac(..)
+        | ast::ExprKind::Struct(..)
+        | ast::ExprKind::Tup(..) => true,
+        ast::ExprKind::AddrOf(_, ref expr)
+        | ast::ExprKind::Box(ref expr)
+        | ast::ExprKind::Try(ref expr)
+        | ast::ExprKind::Unary(_, ref expr)
+        | ast::ExprKind::Cast(ref expr, _) => can_extend_match_arm_body(expr),
+        _ => false,
+    }
+}
+
 pub fn rewrite_literal(context: &RewriteContext, l: &ast::Lit, shape: Shape) -> Option<String> {
     match l.node {
         ast::LitKind::Str(_, ast::StrStyle::Cooked) => rewrite_string_lit(context, l.span, shape),

src/issues.rs

@@ -190,19 +190,25 @@ impl BadIssueSeeker {
         }
 
         match part {
-            NumberPart::OpenParen => if c != '(' {
-                return IssueClassification::Bad(issue);
-            } else {
-                part = NumberPart::Pound;
-            },
-            NumberPart::Pound => if c == '#' {
-                part = NumberPart::Number;
-            },
-            NumberPart::Number => if c >= '0' && c <= '9' {
-                part = NumberPart::CloseParen;
-            } else {
-                return IssueClassification::Bad(issue);
-            },
+            NumberPart::OpenParen => {
+                if c != '(' {
+                    return IssueClassification::Bad(issue);
+                } else {
+                    part = NumberPart::Pound;
+                }
+            }
+            NumberPart::Pound => {
+                if c == '#' {
+                    part = NumberPart::Number;
+                }
+            }
+            NumberPart::Number => {
+                if c >= '0' && c <= '9' {
+                    part = NumberPart::CloseParen;
+                } else {
+                    return IssueClassification::Bad(issue);
+                }
+            }
             NumberPart::CloseParen => {}
         }
 

src/items.rs

@@ -550,12 +550,14 @@ impl<'a> FmtVisitor<'a> {
                 self.block_indent,
                 Some(one_line_width),
             )?,
-            ast::VariantData::Unit(..) => if let Some(ref expr) = field.node.disr_expr {
-                let lhs = format!("{} =", field.node.name);
-                rewrite_assign_rhs(&context, lhs, &**expr, shape)?
-            } else {
-                field.node.name.to_string()
-            },
+            ast::VariantData::Unit(..) => {
+                if let Some(ref expr) = field.node.disr_expr {
+                    let lhs = format!("{} =", field.node.name);
+                    rewrite_assign_rhs(&context, lhs, &**expr, shape)?
+                } else {
+                    field.node.name.to_string()
+                }
+            }
         };
 
         let attrs_extendable = attrs_str.is_empty()
@@ -643,11 +645,13 @@ pub fn format_impl(
             _ if last_line_contains_single_line_comment(&result) => result.push_str(&sep),
             BraceStyle::AlwaysNextLine => result.push_str(&sep),
             BraceStyle::PreferSameLine => result.push(' '),
-            BraceStyle::SameLineWhere => if !where_clause_str.is_empty() {
-                result.push_str(&sep);
-            } else {
-                result.push(' ');
-            },
+            BraceStyle::SameLineWhere => {
+                if !where_clause_str.is_empty() {
+                    result.push_str(&sep);
+                } else {
+                    result.push(' ');
+                }
+            }
         }
 
         result.push('{');
@@ -1039,14 +1043,16 @@ pub fn format_trait(context: &RewriteContext, item: &ast::Item, offset: Indent)
                 result.push_str(&offset.to_string(context.config));
             }
             BraceStyle::PreferSameLine => result.push(' '),
-            BraceStyle::SameLineWhere => if !where_clause_str.is_empty()
-                && (!trait_items.is_empty() || result.contains('\n'))
-            {
-                result.push('\n');
-                result.push_str(&offset.to_string(context.config));
-            } else {
-                result.push(' ');
-            },
+            BraceStyle::SameLineWhere => {
+                if !where_clause_str.is_empty()
+                    && (!trait_items.is_empty() || result.contains('\n'))
+                {
+                    result.push('\n');
+                    result.push_str(&offset.to_string(context.config));
+                } else {
+                    result.push(' ');
+                }
+            }
         }
         result.push('{');
 

src/macros.rs

@@ -126,11 +126,13 @@ pub fn rewrite_macro(
 
     let macro_name = match extra_ident {
         None => format!("{}!", mac.node.path),
-        Some(ident) => if ident == symbol::keywords::Invalid.ident() {
-            format!("{}!", mac.node.path)
-        } else {
-            format!("{}! {}", mac.node.path, ident)
-        },
+        Some(ident) => {
+            if ident == symbol::keywords::Invalid.ident() {
+                format!("{}!", mac.node.path)
+            } else {
+                format!("{}! {}", mac.node.path, ident)
+            }
+        }
     };
 
     let style = if FORCED_BRACKET_MACROS.contains(&&macro_name[..]) {

src/patterns.rs

@@ -51,11 +51,13 @@ impl Rewrite for Pat {
 
                 Some(format!("{}{}{}{}", prefix, mut_infix, id_str, sub_pat))
             }
-            PatKind::Wild => if 1 <= shape.width {
-                Some("_".to_owned())
-            } else {
-                None
-            },
+            PatKind::Wild => {
+                if 1 <= shape.width {
+                    Some("_".to_owned())
+                } else {
+                    None
+                }
+            }
             PatKind::Range(ref lhs, ref rhs, ref end_kind) => {
                 let infix = match *end_kind {
                     RangeEnd::Included(RangeSyntax::DotDotDot) => "...",

src/types.rs

@@ -720,11 +720,13 @@ impl Rewrite for ast::Ty {
                     SeparatorPlace::Back,
                 )
             }
-            ast::TyKind::Infer => if shape.width >= 1 {
-                Some("_".to_owned())
-            } else {
-                None
-            },
+            ast::TyKind::Infer => {
+                if shape.width >= 1 {
+                    Some("_".to_owned())
+                } else {
+                    None
+                }
+            }
             ast::TyKind::BareFn(ref bare_fn) => rewrite_bare_fn(bare_fn, self.span, context, shape),
             ast::TyKind::Never => Some(String::from("!")),
             ast::TyKind::Mac(..) => None,

src/visitor.rs

@@ -321,10 +321,12 @@ impl<'a> FmtVisitor<'a> {
                     attrs = &filtered_attrs;
                 }
             }
-            _ => if self.visit_attrs(&item.attrs, ast::AttrStyle::Outer) {
-                self.push_rewrite(item.span, None);
-                return;
-            },
+            _ => {
+                if self.visit_attrs(&item.attrs, ast::AttrStyle::Outer) {
+                    self.push_rewrite(item.span, None);
+                    return;
+                }
+            }
         }
 
         match item.node {

tests/target/configs-force_multiline_block-false.rs

@@ -3,9 +3,11 @@
 
 fn main() {
     match lorem {
-        Lorem::Ipsum => if ipsum {
-            println!("dolor");
-        },
+        Lorem::Ipsum => {
+            if ipsum {
+                println!("dolor");
+            }
+        }
         Lorem::Dolor => println!("amet"),
     }
 }