From 150765d755fdfcab5d6f2949be7ad9df37e36e86 Mon Sep 17 00:00:00 2001
From: csmoe <35686186+csmoe@users.noreply.github.com>
Date: Mon, 21 May 2018 12:18:06 +0800
Subject: [PATCH] format label break

---
 src/expr.rs                 |  7 ++++---
 tests/source/label_break.rs | 16 ++++++++++++++++
 tests/target/label_break.rs | 16 ++++++++++++++++
 3 files changed, 36 insertions(+), 3 deletions(-)
 create mode 100644 tests/source/label_break.rs
 create mode 100644 tests/target/label_break.rs

diff --git a/src/expr.rs b/src/expr.rs
index 8961cec4240..f1cfe8b4c4c 100644
--- a/src/expr.rs
+++ b/src/expr.rs
@@ -118,8 +118,7 @@ pub fn format_expr(
         | ast::ExprKind::While(..)
         | ast::ExprKind::WhileLet(..) => to_control_flow(expr, expr_type)
             .and_then(|control_flow| control_flow.rewrite(context, shape)),
-        // FIXME(topecongiro): Handle label on a block (#2722).
-        ast::ExprKind::Block(ref block, _) => {
+        ast::ExprKind::Block(ref block, opt_label) => {
             match expr_type {
                 ExprType::Statement => {
                     if is_unsafe_block(block) {
@@ -131,9 +130,11 @@ pub fn format_expr(
                         rw
                     } else {
                         let prefix = block_prefix(context, block, shape)?;
+                        let label_string = rewrite_label(opt_label);
+
                         rewrite_block_with_visitor(
                             context,
-                            &prefix,
+                            &format!("{}{}", &prefix, &label_string),
                             block,
                             Some(&expr.attrs),
                             shape,
diff --git a/tests/source/label_break.rs b/tests/source/label_break.rs
new file mode 100644
index 00000000000..d1e34bce4d4
--- /dev/null
+++ b/tests/source/label_break.rs
@@ -0,0 +1,16 @@
+// format with label break value.
+fn main() {
+
+'empty_block: {}
+
+let result = 'block: {
+    if foo() {
+        // comment
+        break 'block 1;
+    }
+    if bar() { /* comment */
+        break 'block      2;
+    }
+    3
+};
+}
\ No newline at end of file
diff --git a/tests/target/label_break.rs b/tests/target/label_break.rs
new file mode 100644
index 00000000000..2e05159de39
--- /dev/null
+++ b/tests/target/label_break.rs
@@ -0,0 +1,16 @@
+// format with label break value.
+fn main() {
+    {}
+
+    let result = {
+        if foo() {
+            // comment
+            break 'block 1;
+        }
+        if bar() {
+            /* comment */
+            break 'block 2;
+        }
+        3
+    };
+}