Ignore missing whitespace after trailing comma in single line paramet…

…er value list Closes #2794
pinterest · Sep 18, 2024 · c0f608b · c0f608b
1 parent a997d75
commit c0f608b
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Showing 2 changed files with 13 additions and 2 deletions.
diff --git a/...d/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/ParameterListSpacingRule.kt b/...d/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/ParameterListSpacingRule.kt
@@ -5,6 +5,7 @@ import com.pinterest.ktlint.rule.engine.core.api.ElementType.ANNOTATION_ENTRY
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.COLON
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.COMMA
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.MODIFIER_LIST
+import com.pinterest.ktlint.rule.engine.core.api.ElementType.RPAR
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.TYPE_REFERENCE
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.VALUE_PARAMETER
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.VALUE_PARAMETER_LIST
@@ -107,10 +108,10 @@ public class ParameterListSpacingRule :
                 }
 
                 COMMA -> {
-                    // Comma must be followed by whitespace
+                    // Comma, except when it is the trailing comma, must be followed by whitespace
                     el
                         .nextLeaf()
-                        ?.takeIf { it.elementType != WHITE_SPACE }
+                        ?.takeUnless { it.elementType == WHITE_SPACE || it.elementType == RPAR }
                         ?.let { addMissingWhiteSpaceAfterMe(el, emit) }
                 }
 

diff --git a/...c/test/kotlin/com/pinterest/ktlint/ruleset/standard/rules/ParameterListSpacingRuleTest.kt b/...c/test/kotlin/com/pinterest/ktlint/ruleset/standard/rules/ParameterListSpacingRuleTest.kt
@@ -511,6 +511,16 @@ class ParameterListSpacingRuleTest {
             .isFormattedAs(formattedCode)
     }
 
+    @Test
+    fun `Issue 2794 - Given a single line function signature and the last parameter is followed by a trailing comma`() {
+        val code =
+            """
+            fun foo(bar: Int,) {
+            }
+            """.trimIndent()
+        parameterListSpacingRuleAssertThat(code).hasNoLintViolations()
+    }
+
     private companion object {
         const val TOO_MANY_SPACES = "  "
     }