Formatter: add line break between comma and semicolon

#KT-34744

idea/formatter/src/org/jetbrains/kotlin/idea/formatter/kotlinSpacingRules.kt

@@ -262,6 +262,8 @@ fun createSpacingBuilder(settings: CodeStyleSettings, builderUtil: KotlinSpacing
 
             between(ENUM_ENTRY, SEMICOLON).spaces(0)
 
+            between(COMMA, SEMICOLON).lineBreakInCodeIf(kotlinCustomSettings.ALLOW_TRAILING_COMMA)
+
             beforeInside(FUN, TokenSet.create(BODY, CLASS_BODY)).lineBreakInCode()
             beforeInside(SECONDARY_CONSTRUCTOR, TokenSet.create(BODY, CLASS_BODY)).lineBreakInCode()
             beforeInside(CLASS, TokenSet.create(BODY, CLASS_BODY)).lineBreakInCode()

idea/testData/formatter/trailingComma/enumEntry/Enum.after.inv.kt

@@ -0,0 +1,43 @@
+// SET_TRUE: ALLOW_TRAILING_COMMA
+
+enum class Enum1 {
+    A, B, ;
+}
+
+enum class Enum2 {
+    A, B;
+}
+
+enum class Enum3 {
+    A, B
+    ;
+}
+
+enum class Enum4 {
+    A, B,
+}
+
+enum class Enum5 {
+    A, B,
+}
+
+enum class Enum6(val a: Int) {
+    A(
+            1
+    ),
+    B,
+}
+
+enum class Enum7(val a: Int) {
+    A(
+            1
+    ),
+    B, ;
+}
+
+enum class Enum8(val a: Int) {
+    A(
+            1
+    ),
+    B;
+}

idea/testData/formatter/trailingComma/enumEntry/Enum.after.kt

@@ -0,0 +1,45 @@
+// SET_TRUE: ALLOW_TRAILING_COMMA
+
+enum class Enum1 {
+    A, B,
+    ;
+}
+
+enum class Enum2 {
+    A, B;
+}
+
+enum class Enum3 {
+    A, B
+    ;
+}
+
+enum class Enum4 {
+    A, B,
+}
+
+enum class Enum5 {
+    A, B,
+}
+
+enum class Enum6(val a: Int) {
+    A(
+            1,
+    ),
+    B,
+}
+
+enum class Enum7(val a: Int) {
+    A(
+            1,
+    ),
+    B,
+    ;
+}
+
+enum class Enum8(val a: Int) {
+    A(
+            1,
+    ),
+    B;
+}

idea/testData/formatter/trailingComma/enumEntry/Enum.kt

@@ -0,0 +1,40 @@
+// SET_TRUE: ALLOW_TRAILING_COMMA
+
+enum class Enum1 {
+    A, B,;
+}
+
+enum class Enum2 {
+    A, B;
+}
+
+enum class Enum3 {
+    A, B
+    ;
+}
+
+enum class Enum4 {
+    A, B,
+}
+
+enum class Enum5 {
+    A, B,
+}
+
+enum class Enum6(val a: Int) {
+    A(
+        1
+    ), B,
+}
+
+enum class Enum7(val a: Int) {
+    A(
+        1
+    ), B,;
+}
+
+enum class Enum8(val a: Int) {
+    A(
+        1
+    ), B;
+}

idea/tests/org/jetbrains/kotlin/formatter/FormatterTestGenerated.java

@@ -1205,6 +1205,24 @@ public class FormatterTestGenerated extends AbstractFormatterTest {
                 }
             }
 
+            @TestMetadata("idea/testData/formatter/trailingComma/enumEntry")
+            @TestDataPath("$PROJECT_ROOT")
+            @RunWith(JUnit3RunnerWithInners.class)
+            public static class EnumEntry extends AbstractFormatterTest {
+                private void runTest(String testDataFilePath) throws Exception {
+                    KotlinTestUtils.runTest(this::doTest, this, testDataFilePath);
+                }
+
+                public void testAllFilesPresentInEnumEntry() throws Exception {
+                    KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("idea/testData/formatter/trailingComma/enumEntry"), Pattern.compile("^([^\\.]+)\\.after\\.kt.*$"), null, true);
+                }
+
+                @TestMetadata("Enum.after.kt")
+                public void testEnum() throws Exception {
+                    runTest("idea/testData/formatter/trailingComma/enumEntry/Enum.after.kt");
+                }
+            }
+
             @TestMetadata("idea/testData/formatter/trailingComma/indices")
             @TestDataPath("$PROJECT_ROOT")
             @RunWith(JUnit3RunnerWithInners.class)
@@ -1785,6 +1803,24 @@ public class FormatterTestGenerated extends AbstractFormatterTest {
                 }
             }
 
+            @TestMetadata("idea/testData/formatter/trailingComma/enumEntry")
+            @TestDataPath("$PROJECT_ROOT")
+            @RunWith(JUnit3RunnerWithInners.class)
+            public static class EnumEntry extends AbstractFormatterTest {
+                private void runTest(String testDataFilePath) throws Exception {
+                    KotlinTestUtils.runTest(this::doTestInverted, this, testDataFilePath);
+                }
+
+                public void testAllFilesPresentInEnumEntry() throws Exception {
+                    KotlinTestUtils.assertAllTestsPresentByMetadataWithExcluded(this.getClass(), new File("idea/testData/formatter/trailingComma/enumEntry"), Pattern.compile("^([^\\.]+)\\.after\\.inv\\.kt.*$"), null, true);
+                }
+
+                @TestMetadata("Enum.after.inv.kt")
+                public void testEnum() throws Exception {
+                    runTest("idea/testData/formatter/trailingComma/enumEntry/Enum.after.inv.kt");
+                }
+            }
+
             @TestMetadata("idea/testData/formatter/trailingComma/indices")
             @TestDataPath("$PROJECT_ROOT")
             @RunWith(JUnit3RunnerWithInners.class)