Allow overflowing rhs of unit variant (#3566)

Author: topecongiro

src/expr.rs

@@ -1894,6 +1894,9 @@ pub(crate) enum RhsTactics {
     Default,
     /// Put the rhs on the next line if it uses multiple line, without extra indentation.
     ForceNextLineWithoutIndent,
+    /// Allow overflowing max width if neither `Default` nor `ForceNextLineWithoutIndent`
+    /// did not work.
+    AllowOverflow,
 }
 
 // The left hand side must contain everything up to, and including, the
@@ -1970,6 +1973,10 @@ fn choose_rhs<R: Rewrite>(
                     Some(format!("{}{}", new_indent_str, new_rhs))
                 }
                 (None, Some(ref new_rhs)) => Some(format!("{}{}", new_indent_str, new_rhs)),
+                (None, None) if rhs_tactics == RhsTactics::AllowOverflow => {
+                    let shape = shape.infinite_width();
+                    expr.rewrite(context, shape).map(|s| format!(" {}", s))
+                }
                 (None, None) => None,
                 (Some(orig_rhs), _) => Some(format!(" {}", orig_rhs)),
             }
@@ -1986,7 +1993,7 @@ fn shape_from_rhs_tactic(
         RhsTactics::ForceNextLineWithoutIndent => shape
             .with_max_width(context.config)
             .sub_width(shape.indent.width()),
-        RhsTactics::Default => {
+        RhsTactics::Default | RhsTactics::AllowOverflow => {
             Shape::indented(shape.indent.block_indent(context.config), context.config)
                 .sub_width(shape.rhs_overhead(context.config))
         }

src/items.rs

@@ -592,7 +592,13 @@ impl<'a> FmtVisitor<'a> {
                         rewrite_ident(&context, field.node.ident),
                         pad_discrim_ident_to
                     );
-                    rewrite_assign_rhs(&context, lhs, &*expr.value, shape)?
+                    rewrite_assign_rhs_with(
+                        &context,
+                        lhs,
+                        &*expr.value,
+                        shape,
+                        RhsTactics::AllowOverflow,
+                    )?
                 } else {
                     rewrite_ident(&context, field.node.ident).to_owned()
                 }

src/shape.rs

@@ -136,6 +136,9 @@ impl Sub<usize> for Indent {
     }
 }
 
+// 8096 is close enough to infinite for rustfmt.
+const INFINITE_SHAPE_WIDTH: usize = 8096;
+
 #[derive(Copy, Clone, Debug)]
 pub(crate) struct Shape {
     pub(crate) width: usize,
@@ -274,6 +277,14 @@ impl Shape {
         offset_indent.alignment = self.offset;
         offset_indent.to_string_inner(config, 0)
     }
+
+    /// Creates a `Shape` with a virtually infinite width.
+    pub(crate) fn infinite_width(&self) -> Shape {
+        Shape {
+            width: INFINITE_SHAPE_WIDTH,
+            ..*self
+        }
+    }
 }
 
 #[cfg(test)]

tests/source/enum.rs

@@ -195,3 +195,10 @@ pub enum QlError {
 // #2594
 enum Foo {}
 enum Bar { }
+
+// #3562
+enum PublishedFileVisibility {
+    Public = sys::ERemoteStoragePublishedFileVisibility_k_ERemoteStoragePublishedFileVisibilityPublic,
+    FriendsOnly = sys::ERemoteStoragePublishedFileVisibility_k_ERemoteStoragePublishedFileVisibilityFriendsOnly,
+    Private = sys::ERemoteStoragePublishedFileVisibility_k_ERemoteStoragePublishedFileVisibilityPrivate,
+}

tests/target/enum.rs

@@ -264,3 +264,12 @@ pub enum QlError {
 // #2594
 enum Foo {}
 enum Bar {}
+
+// #3562
+enum PublishedFileVisibility {
+    Public =
+        sys::ERemoteStoragePublishedFileVisibility_k_ERemoteStoragePublishedFileVisibilityPublic,
+    FriendsOnly = sys::ERemoteStoragePublishedFileVisibility_k_ERemoteStoragePublishedFileVisibilityFriendsOnly,
+    Private =
+        sys::ERemoteStoragePublishedFileVisibility_k_ERemoteStoragePublishedFileVisibilityPrivate,
+}