Make sure enums are always laid out vertically

Close #266

Author: NathanLovato

CHANGELOG.md

@@ -21,6 +21,7 @@ This file documents the changes made to the formatter with each release.
 - Remove all `unwrap()` calls from the project and follow stricter linting rules (#145)
 - Remove multiple third-party dependencies and greatly improve compilation speed
 - Improve performance by an order of magnitude (10x to over 50x speedup depending on the case)
+- Always lay enums vertically (one member per line) (#266)
 
 ### Fixed
 

src/formatter.rs

@@ -1238,7 +1238,9 @@ fn process_container(
 ) {
     let node_kind = GDScriptNodeKind::get_kind_from_ast_node(node);
     let child_count = node.child_count();
-    if child_count < 3 {
+    // The style guide requires enum members to be written vertically, even
+    // when the list would fit on one line. Empty enums are the only exception.
+    if child_count < 3 && node_kind != GDScriptNodeKind::EnumeratorList {
         if let Some(open) = node.child(0) {
             process_node(input, open, render_elements);
         }
@@ -1371,6 +1373,7 @@ fn process_container(
     // for a forced line break.
     const MIN_CHILD_COUNT_BEYOND_SINGLE_ELEMENT: usize = 4;
     let contains_more_than_one_element = child_count >= MIN_CHILD_COUNT_BEYOND_SINGLE_ELEMENT;
+    let is_non_empty_enum = node_kind == GDScriptNodeKind::EnumeratorList;
     // A single lambda in a collection will cause a syntax error unless we wrap
     // it in parentheses or insert a trailing comma on the last line
     let mut is_array_with_single_lambda = false;
@@ -1395,12 +1398,20 @@ fn process_container(
         render_elements.push(RenderElement::TextStatic(","));
     }
 
-    if contains_more_than_one_element && let Some(open) = node.child(0) {
+    // A single enum member also needs a trailing comma in its mandatory
+    // multiline layout.
+    if is_non_empty_enum && !contains_more_than_one_element && !trailing_comma_handled {
+        render_elements.push(RenderElement::TextStatic(","));
+    }
+
+    if (contains_more_than_one_element || is_non_empty_enum)
+        && let Some(open) = node.child(0)
+    {
         let close_byte = node
             .child((child_count - 1) as u32)
             .expect("container node has close delimiter")
             .start_byte();
-        if has_newline(input.source, open.end_byte(), close_byte) {
+        if is_non_empty_enum || has_newline(input.source, open.end_byte(), close_byte) {
             render_elements.push(RenderElement::ForceBreakingParent);
         }
     }

tests/expected/enums.gd

@@ -1,9 +1,16 @@
 # Enum spacing and wrapping
-# Single line enum get spaces between members, multi-line enums get 1 indent and
-# trailing commas.
-enum { A, B, C }
+# Enums are always vertical, with one indent and trailing commas.
+enum {
+	A,
+	B,
+	C,
+}
 
-enum Named { A, B, C }
+enum Named {
+	A,
+	B,
+	C,
+}
 
 enum ThirdEnum {
 	Aaaaaaaaaaaaaaaaaaaaaa,
@@ -25,3 +32,7 @@ enum Test {
 	A,
 	B,
 }
+
+enum Single {
+	ONLY,
+}

tests/expected/trailing_comma.gd

@@ -42,7 +42,11 @@ enum Foo2 {
 	C, # comment
 }
 
-enum Foo3 { A, B, C }
+enum Foo3 {
+	A,
+	B,
+	C,
+}
 
 
 func foo(

tests/input/enums.gd

@@ -1,6 +1,5 @@
 # Enum spacing and wrapping
-# Single line enum get spaces between members, multi-line enums get 1 indent and
-# trailing commas.
+# Enums are always vertical, with one indent and trailing commas.
 enum {A,B,C}
 
 
@@ -23,3 +22,5 @@ func foo():
 
 enum Test {
 	A, B }
+
+enum Single { ONLY }

tests/reorder_code/expected/reorder_complete.gd

@@ -6,8 +6,15 @@ extends Node
 
 signal test_signal(value: int)
 
-enum TestEnum { OPTION_A, OPTION_B, OPTION_C }
-enum { UNNAMED_A, UNNAMED_B }
+enum TestEnum {
+	OPTION_A,
+	OPTION_B,
+	OPTION_C,
+}
+enum {
+	UNNAMED_A,
+	UNNAMED_B,
+}
 
 const TEST_CONSTANT = 42
 const _PRIVATE_CONSTANT = "hidden"