fix: surround template literal type unions with newlines when too long

src/generation/generate.rs

@@ -3279,6 +3279,7 @@ fn gen_template_literal<'a>(quasis: Vec<Node<'a>>, exprs: Vec<Node<'a>>, context
       Node::OptChainExpr(expr) => get_possible_surround_newlines(expr.base.as_node()),
       Node::CondExpr(_) => true,
       Node::BinExpr(_) => true,
+      Node::TsUnionType(_) | Node::TsIntersectionType(_) => true,
       Node::MemberExpr(expr) => !keep_member_expr_on_one_line(expr),
       Node::CallExpr(expr) => !keep_call_expr_on_one_line(expr.into()),
       Node::OptCall(expr) => !keep_call_expr_on_one_line(expr.into()),

tests/specs/types/TplLitType/TplLitType_All.txt

@@ -1,5 +1,28 @@
+~~ lineWidth: 80, indentWidth: 2 ~~
 == should format a template literal type ==
 type Test<T> = `${string    &    keyof    T}Changed`;
 
 [expect]
 type Test<T> = `${string & keyof T}Changed`;
+
+== should keep union template literal type expression on one line when it fits ==
+type Foo = `${typeof X | typeof Y}__${typeof Z | typeof W}`;
+
+[expect]
+type Foo = `${typeof X | typeof Y}__${typeof Z | typeof W}`;
+
+== should surround union template literal type expression with newlines when too long ==
+export type SortSelector = `${typeof Descending | typeof Ascending}${SortItems}`;
+
+[expect]
+export type SortSelector = `${
+  typeof Descending | typeof Ascending
+}${SortItems}`;
+
+== should surround intersection template literal type expression with newlines when too long ==
+export type IntersectionTpl = `${typeof Descending & typeof Ascending}${SortItems}`;
+
+[expect]
+export type IntersectionTpl = `${
+  typeof Descending & typeof Ascending
+}${SortItems}`;