Fix for issue 4689 - indentation on multiline single generic bound (#4730)
diff --git a/src/formatting/types.rs b/src/formatting/types.rs
index 27768d5..efdb5af 100644
--- a/src/formatting/types.rs
+++ b/src/formatting/types.rs
@@ -952,6 +952,24 @@
ast::GenericBound::Trait(..) => last_line_extendable(s),
};
+ // Whether a PathSegment segment includes internal array containing more than one item
+ let is_segment_with_multi_items_array = |seg: &ast::PathSegment| {
+ if let Some(args_in) = &seg.args {
+ match &**args_in {
+ ast::AngleBracketed(args) => {
+ if args.args.len() > 1 {
+ true
+ } else {
+ false
+ }
+ }
+ _ => false,
+ }
+ } else {
+ false
+ }
+ };
+
let result = items.iter().enumerate().try_fold(
(String::new(), None, false),
|(strs, prev_trailing_span, prev_extendable), (i, item)| {
@@ -1046,10 +1064,33 @@
},
)?;
- if !force_newline
- && items.len() > 1
- && (result.0.contains('\n') || result.0.len() > shape.width)
- {
+ // Whether retry the function with forced newline is needed:
+ // Only if result is not already multiline and did not exceed line width,
+ // and either there is more than one item;
+ // or the single item is of type `Trait`,
+ // and any of the internal arrays contains more than one item;
+ let retry_with_force_newline =
+ if force_newline || (!result.0.contains('\n') && result.0.len() <= shape.width) {
+ false
+ } else {
+ if items.len() > 1 {
+ true
+ } else {
+ match items[0] {
+ ast::GenericBound::Trait(ref poly_trait_ref, ..) => {
+ let segments = &poly_trait_ref.trait_ref.path.segments;
+ if segments.len() > 1 {
+ true
+ } else {
+ is_segment_with_multi_items_array(&segments[0])
+ }
+ }
+ _ => false,
+ }
+ }
+ };
+
+ if retry_with_force_newline {
join_bounds_inner(context, shape, items, need_indent, true)
} else {
Some(result.0)
diff --git a/tests/source/issue-4689.rs b/tests/source/issue-4689.rs
new file mode 100644
index 0000000..83bbfde
--- /dev/null
+++ b/tests/source/issue-4689.rs
@@ -0,0 +1,147 @@
+// Based on the issue description
+pub trait PrettyPrinter<'tcx>:
+Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+>
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+> + fmt::Write
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+> + fmt::Write1 + fmt::Write2
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+fmt::Write + Printer<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+>
+{
+//
+}
+pub trait PrettyPrinter<'tcx>:
+fmt::Write + Printer1<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+> + Printer2<
+'tcx,
+Error = fmt::Error,
+Path = Self,
+Region = Self,
+Type = Self,
+DynExistential = Self,
+Const = Self,
+>
+{
+//
+}
+
+// Some test cases to ensure other cases formatting were not changed
+fn f() -> Box<
+FnMut() -> Thing<
+WithType = LongItemName,
+Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+>,
+> {
+}
+fn f() -> Box<
+FnMut() -> Thing<
+WithType = LongItemName,
+Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+> + fmt::Write1
++ fmt::Write2,
+> {
+}
+
+fn foo<F>(foo2: F)
+where
+F: Fn(
+// this comment is deleted
+)
+{
+}
+fn foo<F>(foo2: F)
+where
+F: Fn(
+// this comment is deleted
+) + fmt::Write
+{
+}
+
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+F: for<> FnMut(
+&mut ProbeContext<>,
+ty::PolyTraitRefffffffffffffffffffffffffffffffff<>,
+tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+),
+{
+}
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+F: for<> FnMut(
+&mut ProbeContext<>,
+ty::PolyTraitRefffffffffffffffffffffffffffffffff<>,
+tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+) + fmt::Write,
+{
+}
+
+fn build_sorted_static_get_entry_names(
+mut entries: entryyyyyyyy,
+) -> (
+impl Fn(
+AlphabeticalTraversal,
+Seconddddddddddddddddddddddddddddddddddd
+) -> Parammmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
++ Sendddddddddddddddddddddddddddddddddddddddddddd
+) {
+}
+
+pub trait SomeTrait:
+Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
++ Eqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
+{
+}
+
+trait B = where
+for<'b> &'b Self: Send
++ Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
++ Copyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy;
diff --git a/tests/target/issue-4689.rs b/tests/target/issue-4689.rs
new file mode 100644
index 0000000..9ad9474
--- /dev/null
+++ b/tests/target/issue-4689.rs
@@ -0,0 +1,150 @@
+// Based on the issue description
+pub trait PrettyPrinter<'tcx>:
+ Printer<
+ 'tcx,
+ Error = fmt::Error,
+ Path = Self,
+ Region = Self,
+ Type = Self,
+ DynExistential = Self,
+ Const = Self,
+ >
+{
+ //
+}
+pub trait PrettyPrinter<'tcx>:
+ Printer<
+ 'tcx,
+ Error = fmt::Error,
+ Path = Self,
+ Region = Self,
+ Type = Self,
+ DynExistential = Self,
+ Const = Self,
+ > + fmt::Write
+{
+ //
+}
+pub trait PrettyPrinter<'tcx>:
+ Printer<
+ 'tcx,
+ Error = fmt::Error,
+ Path = Self,
+ Region = Self,
+ Type = Self,
+ DynExistential = Self,
+ Const = Self,
+ > + fmt::Write1
+ + fmt::Write2
+{
+ //
+}
+pub trait PrettyPrinter<'tcx>:
+ fmt::Write
+ + Printer<
+ 'tcx,
+ Error = fmt::Error,
+ Path = Self,
+ Region = Self,
+ Type = Self,
+ DynExistential = Self,
+ Const = Self,
+ >
+{
+ //
+}
+pub trait PrettyPrinter<'tcx>:
+ fmt::Write
+ + Printer1<
+ 'tcx,
+ Error = fmt::Error,
+ Path = Self,
+ Region = Self,
+ Type = Self,
+ DynExistential = Self,
+ Const = Self,
+ > + Printer2<
+ 'tcx,
+ Error = fmt::Error,
+ Path = Self,
+ Region = Self,
+ Type = Self,
+ DynExistential = Self,
+ Const = Self,
+ >
+{
+ //
+}
+
+// Some test cases to ensure other cases formatting were not changed
+fn f() -> Box<
+ FnMut() -> Thing<
+ WithType = LongItemName,
+ Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+ >,
+> {
+}
+fn f() -> Box<
+ FnMut() -> Thing<
+ WithType = LongItemName,
+ Error = LONGLONGLONGLONGLONGONGEvenLongerErrorNameLongerLonger,
+ > + fmt::Write1
+ + fmt::Write2,
+> {
+}
+
+fn foo<F>(foo2: F)
+where
+ F: Fn(
+ // this comment is deleted
+ ),
+{
+}
+fn foo<F>(foo2: F)
+where
+ F: Fn(
+ // this comment is deleted
+ ) + fmt::Write,
+{
+}
+
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+ F: FnMut(
+ &mut ProbeContext,
+ ty::PolyTraitRefffffffffffffffffffffffffffffffff,
+ tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+ ),
+{
+}
+fn elaborate_bounds<F>(mut mk_cand: F)
+where
+ F: FnMut(
+ &mut ProbeContext,
+ ty::PolyTraitRefffffffffffffffffffffffffffffffff,
+ tyyyyyyyyyyyyyyyyyyyyy::AssociatedItem,
+ ) + fmt::Write,
+{
+}
+
+fn build_sorted_static_get_entry_names(
+ mut entries: entryyyyyyyy,
+) -> (
+ impl Fn(
+ AlphabeticalTraversal,
+ Seconddddddddddddddddddddddddddddddddddd,
+ ) -> Parammmmmmmmmmmmmmmmmmmmmmmmmmmmmmmm
+ + Sendddddddddddddddddddddddddddddddddddddddddddd
+) {
+}
+
+pub trait SomeTrait:
+ Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
+ + Eqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqqq
+{
+}
+
+trait B = where
+ for<'b> &'b Self: Send
+ + Cloneeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeeee
+ + Copyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyyy;
