Filter out block comment in filter_normal_code (#4668)

Add idempotent tests for wrapping block-style comment

Author: ChinYing-Li

Diff for: src/formatting/comment.rs

@@ -1422,7 +1422,9 @@ impl<'a> Iterator for LineClasses<'a> {
             None => unreachable!(),
         };
 
+        let mut prev_kind = FullCodeCharKind::Normal;
         while let Some((kind, c)) = self.base.next() {
+            prev_kind = self.kind;
             // needed to set the kind of the ending character on the last line
             self.kind = kind;
             if c == '\n' {
@@ -1439,6 +1441,9 @@ impl<'a> Iterator for LineClasses<'a> {
                     (FullCodeCharKind::InStringCommented, FullCodeCharKind::InComment) => {
                         FullCodeCharKind::EndStringCommented
                     }
+                    (_, FullCodeCharKind::Normal) if prev_kind == FullCodeCharKind::EndComment => {
+                        FullCodeCharKind::EndComment
+                    }
                     _ => kind,
                 };
                 break;
@@ -1993,12 +1998,28 @@ fn main() {
 }
 "#;
         assert_eq!(s, filter_normal_code(s));
-        let s_with_comment = r#"
+        let s_with_line_comment = r#"
 fn main() {
     // hello, world
     println!("hello, world");
 }
 "#;
-        assert_eq!(s, filter_normal_code(s_with_comment));
+        assert_eq!(s, filter_normal_code(s_with_line_comment));
+        let s_with_block_comment = r#"
+fn main() {
+    /* hello, world */
+    println!("hello, world");
+}
+"#;
+        assert_eq!(s, filter_normal_code(s_with_block_comment));
+        let s_with_multi_line_comment = r#"
+fn main() {
+    /* hello,
+     * world
+     */
+    println!("hello, world");
+}
+"#;
+        assert_eq!(s, filter_normal_code(s_with_multi_line_comment));
     }
 }

Diff for: tests/source/comment2.rs

@@ -2,3 +2,11 @@
 
 /// This is a long line that angers rustfmt. Rustfmt shall deal with it swiftly and justly.
 pub mod foo {}
+
+fn chains() {
+    test().map(|| {
+        let x = 11;
+        /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam lectus. Sed sit amet ipsum mauris. Maecenas congue
+         * ligula ac quam */ x
+    });
+}

Diff for: tests/source/comment4.rs

@@ -50,3 +50,46 @@ fn debug_function() {
 #[no_mangle] // Test this attribute is preserved.
 #[cfg_attr(rustfmt, rustfmt::skip)]
 pub static ISSUE_1284: [i32; 16] = [];
+
+// issue 4668
+fn f() {
+    fn g() -> int {
+        let foo = 12;
+        match foo {
+            0..=10 => {
+                /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex. */
+            }
+            _ => {
+                let st = None;
+                let res = st.unwrap_or(
+                    /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex. */ "abc"
+                );
+            }
+        }
+    }
+}
+
+fn h() {
+    let mut y = 0;
+    while let x = vec![1, 2, 3]
+        .iter()
+        /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex... */
+        .take(3)
+        .skip(1)
+        .to_owned()
+        .next()
+    {
+        y += x.unwrap_or_else(|/* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex... */_| &0) * 2;
+    }
+}
+
+pub fn t(x: int) {
+    if x == 3 {
+        let y = match context {
+            True => {
+                |x| /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex... */ x+2
+            }
+            False => |x| x,
+        };
+    } else {}
+}

Diff for: tests/source/issue-4668.rs

@@ -0,0 +1,2 @@
+const C: usize = 0_usize;
+const U: usize = /* A long block-style comment A long block-style comment A long block-style comment A long block-style comment */ if C > 0 { 4 } else { 3 };

Diff for: tests/target/comment2.rs

@@ -3,3 +3,12 @@
 /// This is a long line that angers rustfmt. Rustfmt shall deal with it swiftly
 /// and justly.
 pub mod foo {}
+
+fn chains() {
+    test().map(|| {
+        let x = 11;
+        /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Donec a diam
+         * lectus. Sed sit amet ipsum mauris. Maecenas congue ligula ac quam */
+        x
+    });
+}

Diff for: tests/target/comment4.rs

@@ -49,3 +49,56 @@ fn debug_function() {
 #[no_mangle] // Test this attribute is preserved.
 #[cfg_attr(rustfmt, rustfmt::skip)]
 pub static ISSUE_1284: [i32; 16] = [];
+
+// issue 4668
+fn f() {
+    fn g() -> int {
+        let foo = 12;
+        match foo {
+            0..=10 => {
+                /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex. */
+            }
+            _ => {
+                let st = None;
+                let res = st.unwrap_or(
+                    /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex. */
+                    "abc",
+                );
+            }
+        }
+    }
+}
+
+fn h() {
+    let mut y = 0;
+    while let x = vec![1, 2, 3]
+        .iter()
+        /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex... */
+        .take(3)
+        .skip(1)
+        .to_owned()
+        .next()
+    {
+        y += x.unwrap_or_else(
+            |
+                /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex... */
+                _,
+            | &0,
+        ) * 2;
+    }
+}
+
+pub fn t(x: int) {
+    if x == 3 {
+        let y = match context {
+            True => {
+                |x| {
+                    /* Lorem ipsum dolor sit amet, consectetur adipiscing elit. Proin urna felis, molestie ex... */
+                    x + 2
+                }
+            }
+            False => |x| x,
+        };
+    } else {
+    }
+}

Diff for: tests/target/issue-4668.rs

@@ -0,0 +1,4 @@
+const C: usize = 0_usize;
+const U: usize =
+    /* A long block-style comment A long block-style comment A long block-style comment A long block-style comment */
+    if C > 0 { 4 } else { 3 };