Ignore reference expressions in chain-method-continuation (#2569)

Simple reference expressions like properties and enum values should be ignored by this rule as they are no method calls. Closes #2455
pinterest · Feb 27, 2024 · befa71d · befa71d
1 parent 773fd1d
commit befa71d
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diff --git a/...rc/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/ChainMethodContinuationRule.kt b/...rc/main/kotlin/com/pinterest/ktlint/ruleset/standard/rules/ChainMethodContinuationRule.kt
@@ -141,6 +141,7 @@ public class ChainMethodContinuationRule :
         chainedExpression
             .chainOperators
             .filterNot { it.isJavaClassReferenceExpression() }
+            .filterNot { it.isSimpleReferenceExpression() }
             .forEach { chainOperator ->
                 when {
                     chainOperator.shouldBeOnSameLineAsClosingElementOfPreviousExpressionInMethodChain() -> {
@@ -160,6 +161,11 @@ public class ChainMethodContinuationRule :
             nextCodeSibling()?.elementType == REFERENCE_EXPRESSION &&
             nextCodeSibling()?.firstChildLeafOrSelf()?.text == "java"
 
+    private fun ASTNode.isSimpleReferenceExpression() =
+        treeParent.elementType == DOT_QUALIFIED_EXPRESSION &&
+            prevCodeSibling()?.elementType == REFERENCE_EXPRESSION &&
+            nextCodeSibling()?.elementType == REFERENCE_EXPRESSION
+
     private fun ChainedExpression.wrapBeforeChainOperator() =
         when {
             hasNewlineBetweenFirstAndLastChainOperator -> {

diff --git a/...est/kotlin/com/pinterest/ktlint/ruleset/standard/rules/ChainMethodContinuationRuleTest.kt b/...est/kotlin/com/pinterest/ktlint/ruleset/standard/rules/ChainMethodContinuationRuleTest.kt
@@ -1011,4 +1011,31 @@ class ChainMethodContinuationRuleTest {
                 LintViolation(6, 46, "Exceeded max line length (45)", false),
             ).hasNoLintViolationsExceptInAdditionalRules()
     }
+
+    @Test
+    fun `Issue 2455 - Given a chained method including some simple reference expressions then do not wrap simple reference expressions`() {
+        val code =
+            """
+            // $MAX_LINE_LENGTH_MARKER      $EOL_CHAR
+            fun buildBar(): Foo.Bar = Foo.Bar.builder().baz().baz.build()
+            """.trimIndent()
+        val formattedCode =
+            """
+            // $MAX_LINE_LENGTH_MARKER      $EOL_CHAR
+            fun buildBar(): Foo.Bar = Foo.Bar
+                .builder()
+                .baz()
+                .baz
+                .build()
+            """.trimIndent()
+        chainMethodContinuationRuleAssertThat(code)
+            .setMaxLineLength()
+            .addAdditionalRuleProvider { MaxLineLengthRule() }
+            .hasLintViolations(
+                LintViolation(2, 34, "Expected newline before '.'"),
+                LintViolation(2, 44, "Expected newline before '.'"),
+                LintViolation(2, 50, "Expected newline before '.'"),
+                LintViolation(2, 54, "Expected newline before '.'"),
+            ).isFormattedAs(formattedCode)
+    }
 }