From 0a2500665d514f27ad06828544c43a6f28924426 Mon Sep 17 00:00:00 2001
From: Paul Dingemans <paul-dingemans@users.noreply.github.com>
Date: Tue, 22 Aug 2023 15:43:59 +0200
Subject: [PATCH] Do not wrap expression after a spread operator (#2193)

Closes #2188
---
 CHANGELOG.md                                  |  3 ++-
 .../rules/MultilineExpressionWrappingRule.kt  |  6 +++++
 .../MultilineExpressionWrappingRuleTest.kt    | 27 +++++++++++++++++++
 3 files changed, 35 insertions(+), 1 deletion(-)

diff --git a/CHANGELOG.md b/CHANGELOG.md
index edc417122b..fff5a9b04a 100644
--- a/CHANGELOG.md
+++ b/CHANGELOG.md
@@ -49,7 +49,8 @@ Class "org.jetbrains.kotlin.com.intellij.treeCopyHandler" is no longer registere
 * Do not wrap a single line enum class `statement-wrapping` [#2177](https://github.com/pinterest/ktlint/issues/2177)
 * Fix alignment of type constraints after `where` keyword in function signature `indent` [#2175](https://github.com/pinterest/ktlint/issues/2175)
 * Fix wrapping of multiline postfix expression `multiline-expression-wrapping` [#2183](https://github.com/pinterest/ktlint/issues/2183)
-* Remove registration of class "org.jetbrains.kotlin.com.intellij.treeCopyHandler" as extension point for the compiler as this is not supported in the embedded Kotlin compiler version 1.9. Also remove Ktlint CLI command line flag `disable-kotlin-extension-point`, and parameter `enableKotlinCompilerExtensionPoint` from `KtLintRuleEngine` to disable the kotlin extension point  [#2061](https://github.com/pinterest/ktlint/issues/2061)
+* Remove registration of class "org.jetbrains.kotlin.com.intellij.treeCopyHandler" as extension point for the compiler as this is not supported in the embedded Kotlin compiler version 1.9. Also remove Ktlint CLI command line flag `disable-kotlin-extension-point`, and parameter `enableKotlinCompilerExtensionPoint` from `KtLintRuleEngine` to disable the kotlin extension point [#2061](https://github.com/pinterest/ktlint/issues/2061)
+* Do not wrap expression after a spread operator `multiline-expression-wrapping` [#2188](https://github.com/pinterest/ktlint/issues/2188)
 
 ### Changed
 
diff --git a/ktlint-ruleset-standard/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/MultilineExpressionWrappingRule.kt b/ktlint-ruleset-standard/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/MultilineExpressionWrappingRule.kt
index 7a9815814c..c2a95fdf68 100644
--- a/ktlint-ruleset-standard/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/MultilineExpressionWrappingRule.kt
+++ b/ktlint-ruleset-standard/src/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/MultilineExpressionWrappingRule.kt
@@ -13,6 +13,7 @@ import com.pinterest.ktlint.rule.engine.core.api.ElementType.EQ
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.FUN
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.IF
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.IS_EXPRESSION
+import com.pinterest.ktlint.rule.engine.core.api.ElementType.MUL
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.OBJECT_LITERAL
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.OPERATION_REFERENCE
 import com.pinterest.ktlint.rule.engine.core.api.ElementType.POSTFIX_EXPRESSION
@@ -74,6 +75,7 @@ public class MultilineExpressionWrappingRule :
         emit: (offset: Int, errorMessage: String, canBeAutoCorrected: Boolean) -> Unit,
     ) {
         if (node.elementType in CHAINABLE_EXPRESSION &&
+            !node.isPartOfSpreadOperatorExpression() &&
             (node.treeParent.elementType !in CHAINABLE_EXPRESSION || node.isRightHandSideOfBinaryExpression())
         ) {
             visitExpression(node, emit, autoCorrect)
@@ -85,6 +87,10 @@ public class MultilineExpressionWrappingRule :
         }
     }
 
+    private fun ASTNode.isPartOfSpreadOperatorExpression() =
+        prevCodeLeaf()?.elementType == MUL &&
+            treeParent.elementType == VALUE_ARGUMENT
+
     private fun visitExpression(
         node: ASTNode,
         emit: (offset: Int, errorMessage: String, canBeAutoCorrected: Boolean) -> Unit,
diff --git a/ktlint-ruleset-standard/src/test/kotlin/com/pinterest/ktlint/ruleset/standard/rules/MultilineExpressionWrappingRuleTest.kt b/ktlint-ruleset-standard/src/test/kotlin/com/pinterest/ktlint/ruleset/standard/rules/MultilineExpressionWrappingRuleTest.kt
index e55d8ec642..017cb4a7e6 100644
--- a/ktlint-ruleset-standard/src/test/kotlin/com/pinterest/ktlint/ruleset/standard/rules/MultilineExpressionWrappingRuleTest.kt
+++ b/ktlint-ruleset-standard/src/test/kotlin/com/pinterest/ktlint/ruleset/standard/rules/MultilineExpressionWrappingRuleTest.kt
@@ -803,4 +803,31 @@ class MultilineExpressionWrappingRuleTest {
             .hasLintViolation(1, 14, "A multiline expression should start on a new line")
             .isFormattedAs(formattedCode)
     }
+
+    @Test
+    fun `Issue 2188 - Given a multiline prefix expression then reformat but do not wrap after prefix operator`() {
+        val code =
+            """
+            val bar = bar(
+                *foo(
+                    "a",
+                    "b"
+                )
+            )
+            """.trimIndent()
+        val formattedCode =
+            """
+            val bar =
+                bar(
+                    *foo(
+                        "a",
+                        "b"
+                    )
+                )
+            """.trimIndent()
+        multilineExpressionWrappingRuleAssertThat(code)
+            .addAdditionalRuleProvider { IndentationRule() }
+            .hasLintViolation(1, 11, "A multiline expression should start on a new line")
+            .isFormattedAs(formattedCode)
+    }
 }