fix: checking block emptiness (#3878)

calebcartwright · topecongiro · commit ed7c0329aff1 · 2019-10-26T11:11:42.000+09:00
diff --git a/src/expr.rs b/src/expr.rs
@@ -421,7 +421,7 @@ fn rewrite_empty_block(
     prefix: &str,
     shape: Shape,
 ) -> Option<String> {
-    if !block.stmts.is_empty() {
+    if block_has_statements(&block) {
         return None;
     }
 
@@ -1165,14 +1165,27 @@ pub(crate) fn is_simple_block_stmt(
         && attrs.map_or(true, |a| a.is_empty())
 }
 
+fn block_has_statements(block: &ast::Block) -> bool {
+    block.stmts.iter().any(|stmt| {
+        if let ast::StmtKind::Semi(ref expr) = stmt.kind {
+            if let ast::ExprKind::Tup(ref tup_exprs) = expr.kind {
+                if tup_exprs.is_empty() {
+                    return false;
+                }
+            }
+        }
+        true
+    })
+}
+
 /// Checks whether a block contains no statements, expressions, comments, or
 /// inner attributes.
 pub(crate) fn is_empty_block(
     context: &RewriteContext<'_>,
     block: &ast::Block,
     attrs: Option<&[ast::Attribute]>,
 ) -> bool {
-    block.stmts.is_empty()
+    !block_has_statements(&block)
         && !block_contains_comment(context, block)
         && attrs.map_or(true, |a| inner_attributes(a).is_empty())
 }
diff --git a/tests/source/control-brace-style-always-next-line.rs b/tests/source/control-brace-style-always-next-line.rs
@@ -2,33 +2,33 @@
 
 fn main() {
     loop {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
         }
 
 
-    'label: loop // loop comment  
+    'label: loop // loop comment
     {
-        ();
+        let foo = ();
     }
 
 
     cond = true;
     while cond {
-        ();
+        let foo = ();
     }
 
 
     'while_label: while cond { // while comment
-        ();
+        let foo = ();
     }
 
 
     for obj in iter {
         for sub_obj in obj
         {
             'nested_while_label: while cond {
-                ();
+                let foo = ();
             }
         }
     }
diff --git a/tests/source/control-brace-style-always-same-line.rs b/tests/source/control-brace-style-always-same-line.rs
@@ -1,32 +1,32 @@
 fn main() {
     loop {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
         }
 
 
-    'label: loop // loop comment  
+    'label: loop // loop comment
     {
-        ();
+        let foo = ();
     }
 
 
     cond = true;
     while cond {
-        ();
+        let foo = ();
     }
 
 
     'while_label: while cond { // while comment
-        ();
+        let foo = ();
     }
 
 
     for obj in iter {
         for sub_obj in obj
         {
             'nested_while_label: while cond {
-                ();
+                let foo = ();
             }
         }
     }
diff --git a/tests/source/else-if-brace-style-always-next-line.rs b/tests/source/else-if-brace-style-always-next-line.rs
@@ -3,14 +3,14 @@
 fn main() {
     if false
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     if false // lone if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
 
@@ -26,29 +26,29 @@ fn main() {
 
     if true
     {
-        ();
+        let foo = ();
     } else if false {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
     else {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 
     if true // else-if-chain if comment
     {
-        ();
+        let foo = ();
     }
     else if false // else-if-chain else-if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     } else // else-if-chain else comment
     {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 }
diff --git a/tests/source/else-if-brace-style-always-same-line.rs b/tests/source/else-if-brace-style-always-same-line.rs
@@ -1,14 +1,14 @@
 fn main() {
     if false
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     if false // lone if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
 
@@ -24,29 +24,29 @@ fn main() {
 
     if true
     {
-        ();
+        let foo = ();
     } else if false {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
     else {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 
     if true // else-if-chain if comment
     {
-        ();
+        let foo = ();
     }
     else if false // else-if-chain else-if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     } else // else-if-chain else comment
     {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 }
diff --git a/tests/source/else-if-brace-style-closing-next-line.rs b/tests/source/else-if-brace-style-closing-next-line.rs
@@ -3,14 +3,14 @@
 fn main() {
     if false
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     if false // lone if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
 
@@ -26,29 +26,29 @@ fn main() {
 
     if true
     {
-        ();
+        let foo = ();
     } else if false {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
     else {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 
     if true // else-if-chain if comment
     {
-        ();
+        let foo = ();
     }
     else if false // else-if-chain else-if comment
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     } else // else-if-chain else comment
     {
-        ();
-        ();
-        ();
+        let foo = ();
+        let bar = ();
+        let baz = ();
     }
 }
diff --git a/tests/source/issue_3868.rs b/tests/source/issue_3868.rs
@@ -0,0 +1,13 @@
+fn foo() {
+    ;
+}
+
+fn bar() {
+    for _ in 0..1 {
+        ;
+    }
+}
+
+fn baz() {
+    ();
+    }
diff --git a/tests/target/control-brace-style-always-next-line.rs b/tests/target/control-brace-style-always-next-line.rs
@@ -3,26 +3,26 @@
 fn main() {
     loop
     {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     'label: loop
     // loop comment
     {
-        ();
+        let foo = ();
     }
 
     cond = true;
     while cond
     {
-        ();
+        let foo = ();
     }
 
     'while_label: while cond
     {
         // while comment
-        ();
+        let foo = ();
     }
 
     for obj in iter
@@ -31,7 +31,7 @@ fn main() {
         {
             'nested_while_label: while cond
             {
-                ();
+                let foo = ();
             }
         }
     }
diff --git a/tests/target/control-brace-style-always-same-line.rs b/tests/target/control-brace-style-always-same-line.rs
@@ -1,29 +1,29 @@
 fn main() {
     loop {
-        ();
-        ();
+        let foo = ();
+        let bar = ();
     }
 
     'label: loop
     // loop comment
     {
-        ();
+        let foo = ();
     }
 
     cond = true;
     while cond {
-        ();
+        let foo = ();
     }
 
     'while_label: while cond {
         // while comment
-        ();
+        let foo = ();
     }
 
     for obj in iter {
         for sub_obj in obj {
             'nested_while_label: while cond {
-                ();
+                let foo = ();
             }
         }
     }
diff --git a/tests/target/else-if-brace-style-always-next-line.rs b/tests/target/else-if-brace-style-always-next-line.rs
diff --git a/tests/target/else-if-brace-style-always-same-line.rs b/tests/target/else-if-brace-style-always-same-line.rs
diff --git a/tests/target/else-if-brace-style-closing-next-line.rs b/tests/target/else-if-brace-style-closing-next-line.rs
diff --git a/tests/target/issue_3868.rs b/tests/target/issue_3868.rs

Original file line number	Diff line number	Diff line change
`@@ -2,33 +2,33 @@`
`2`	`2`
`3`	`3`	`fn main() {`
`4`	`4`	`loop {`
`5`		`- ();`
`6`		`- ();`
	`5`	`+ let foo = ();`
	`6`	`+ let bar = ();`
`7`	`7`	`}`
`8`	`8`
`9`	`9`
`10`		`- 'label: loop // loop comment`
	`10`	`+ 'label: loop // loop comment`
`11`	`11`	`{`
`12`		`- ();`
	`12`	`+ let foo = ();`
`13`	`13`	`}`
`14`	`14`
`15`	`15`
`16`	`16`	`cond = true;`
`17`	`17`	`while cond {`
`18`		`- ();`
	`18`	`+ let foo = ();`
`19`	`19`	`}`
`20`	`20`
`21`	`21`
`22`	`22`	`'while_label: while cond { // while comment`
`23`		`- ();`
	`23`	`+ let foo = ();`
`24`	`24`	`}`
`25`	`25`
`26`	`26`
`27`	`27`	`for obj in iter {`
`28`	`28`	`for sub_obj in obj`
`29`	`29`	`{`
`30`	`30`	`'nested_while_label: while cond {`
`31`		`- ();`
	`31`	`+ let foo = ();`
`32`	`32`	`}`
`33`	`33`	`}`
`34`	`34`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,32 +1,32 @@`
`1`	`1`	`fn main() {`
`2`	`2`	`loop {`
`3`		`- ();`
`4`		`- ();`
	`3`	`+ let foo = ();`
	`4`	`+ let bar = ();`
`5`	`5`	`}`
`6`	`6`
`7`	`7`
`8`		`- 'label: loop // loop comment`
	`8`	`+ 'label: loop // loop comment`
`9`	`9`	`{`
`10`		`- ();`
	`10`	`+ let foo = ();`
`11`	`11`	`}`
`12`	`12`
`13`	`13`
`14`	`14`	`cond = true;`
`15`	`15`	`while cond {`
`16`		`- ();`
	`16`	`+ let foo = ();`
`17`	`17`	`}`
`18`	`18`
`19`	`19`
`20`	`20`	`'while_label: while cond { // while comment`
`21`		`- ();`
	`21`	`+ let foo = ();`
`22`	`22`	`}`
`23`	`23`
`24`	`24`
`25`	`25`	`for obj in iter {`
`26`	`26`	`for sub_obj in obj`
`27`	`27`	`{`
`28`	`28`	`'nested_while_label: while cond {`
`29`		`- ();`
	`29`	`+ let foo = ();`
`30`	`30`	`}`
`31`	`31`	`}`
`32`	`32`	`}`
Original file line number	Diff line number	Diff line change
`@@ -3,14 +3,14 @@`
`3`	`3`	`fn main() {`
`4`	`4`	`if false`
`5`	`5`	`{`
`6`		`- ();`
`7`		`- ();`
	`6`	`+ let foo = ();`
	`7`	`+ let bar = ();`
`8`	`8`	`}`
`9`	`9`
`10`	`10`	`if false // lone if comment`
`11`	`11`	`{`
`12`		`- ();`
`13`		`- ();`
	`12`	`+ let foo = ();`
	`13`	`+ let bar = ();`
`14`	`14`	`}`
`15`	`15`
`16`	`16`
`@@ -26,29 +26,29 @@ fn main() {`
`26`	`26`
`27`	`27`	`if true`
`28`	`28`	`{`
`29`		`- ();`
	`29`	`+ let foo = ();`
`30`	`30`	`} else if false {`
`31`		`- ();`
`32`		`- ();`
	`31`	`+ let foo = ();`
	`32`	`+ let bar = ();`
`33`	`33`	`}`
`34`	`34`	`else {`
`35`		`- ();`
`36`		`- ();`
`37`		`- ();`
	`35`	`+ let foo = ();`
	`36`	`+ let bar = ();`
	`37`	`+ let baz = ();`
`38`	`38`	`}`
`39`	`39`
`40`	`40`	`if true // else-if-chain if comment`
`41`	`41`	`{`
`42`		`- ();`
	`42`	`+ let foo = ();`
`43`	`43`	`}`
`44`	`44`	`else if false // else-if-chain else-if comment`
`45`	`45`	`{`
`46`		`- ();`
`47`		`- ();`
	`46`	`+ let foo = ();`
	`47`	`+ let bar = ();`
`48`	`48`	`} else // else-if-chain else comment`
`49`	`49`	`{`
`50`		`- ();`
`51`		`- ();`
`52`		`- ();`
	`50`	`+ let foo = ();`
	`51`	`+ let bar = ();`
	`52`	`+ let baz = ();`
`53`	`53`	`}`
`54`	`54`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,14 +1,14 @@`
`1`	`1`	`fn main() {`
`2`	`2`	`if false`
`3`	`3`	`{`
`4`		`- ();`
`5`		`- ();`
	`4`	`+ let foo = ();`
	`5`	`+ let bar = ();`
`6`	`6`	`}`
`7`	`7`
`8`	`8`	`if false // lone if comment`
`9`	`9`	`{`
`10`		`- ();`
`11`		`- ();`
	`10`	`+ let foo = ();`
	`11`	`+ let bar = ();`
`12`	`12`	`}`
`13`	`13`
`14`	`14`
`@@ -24,29 +24,29 @@ fn main() {`
`24`	`24`
`25`	`25`	`if true`
`26`	`26`	`{`
`27`		`- ();`
	`27`	`+ let foo = ();`
`28`	`28`	`} else if false {`
`29`		`- ();`
`30`		`- ();`
	`29`	`+ let foo = ();`
	`30`	`+ let bar = ();`
`31`	`31`	`}`
`32`	`32`	`else {`
`33`		`- ();`
`34`		`- ();`
`35`		`- ();`
	`33`	`+ let foo = ();`
	`34`	`+ let bar = ();`
	`35`	`+ let baz = ();`
`36`	`36`	`}`
`37`	`37`
`38`	`38`	`if true // else-if-chain if comment`
`39`	`39`	`{`
`40`		`- ();`
	`40`	`+ let foo = ();`
`41`	`41`	`}`
`42`	`42`	`else if false // else-if-chain else-if comment`
`43`	`43`	`{`
`44`		`- ();`
`45`		`- ();`
	`44`	`+ let foo = ();`
	`45`	`+ let bar = ();`
`46`	`46`	`} else // else-if-chain else comment`
`47`	`47`	`{`
`48`		`- ();`
`49`		`- ();`
`50`		`- ();`
	`48`	`+ let foo = ();`
	`49`	`+ let bar = ();`
	`50`	`+ let baz = ();`
`51`	`51`	`}`
`52`	`52`	`}`
Original file line number	Diff line number	Diff line change
`@@ -3,26 +3,26 @@`
`3`	`3`	`fn main() {`
`4`	`4`	`loop`
`5`	`5`	`{`
`6`		`- ();`
`7`		`- ();`
	`6`	`+ let foo = ();`
	`7`	`+ let bar = ();`
`8`	`8`	`}`
`9`	`9`
`10`	`10`	`'label: loop`
`11`	`11`	`// loop comment`
`12`	`12`	`{`
`13`		`- ();`
	`13`	`+ let foo = ();`
`14`	`14`	`}`
`15`	`15`
`16`	`16`	`cond = true;`
`17`	`17`	`while cond`
`18`	`18`	`{`
`19`		`- ();`
	`19`	`+ let foo = ();`
`20`	`20`	`}`
`21`	`21`
`22`	`22`	`'while_label: while cond`
`23`	`23`	`{`
`24`	`24`	`// while comment`
`25`		`- ();`
	`25`	`+ let foo = ();`
`26`	`26`	`}`
`27`	`27`
`28`	`28`	`for obj in iter`
`@@ -31,7 +31,7 @@ fn main() {`
`31`	`31`	`{`
`32`	`32`	`'nested_while_label: while cond`
`33`	`33`	`{`
`34`		`- ();`
	`34`	`+ let foo = ();`
`35`	`35`	`}`
`36`	`36`	`}`
`37`	`37`	`}`
Original file line number	Diff line number	Diff line change
`@@ -1,29 +1,29 @@`
`1`	`1`	`fn main() {`
`2`	`2`	`loop {`
`3`		`- ();`
`4`		`- ();`
	`3`	`+ let foo = ();`
	`4`	`+ let bar = ();`
`5`	`5`	`}`
`6`	`6`
`7`	`7`	`'label: loop`
`8`	`8`	`// loop comment`
`9`	`9`	`{`
`10`		`- ();`
	`10`	`+ let foo = ();`
`11`	`11`	`}`
`12`	`12`
`13`	`13`	`cond = true;`
`14`	`14`	`while cond {`
`15`		`- ();`
	`15`	`+ let foo = ();`
`16`	`16`	`}`
`17`	`17`
`18`	`18`	`'while_label: while cond {`
`19`	`19`	`// while comment`
`20`		`- ();`
	`20`	`+ let foo = ();`
`21`	`21`	`}`
`22`	`22`
`23`	`23`	`for obj in iter {`
`24`	`24`	`for sub_obj in obj {`
`25`	`25`	`'nested_while_label: while cond {`
`26`		`- ();`
	`26`	`+ let foo = ();`
`27`	`27`	`}`
`28`	`28`	`}`
`29`	`29`	`}`