From 0c27280f74a668a9abe98b9bbd97aa358fd3475a Mon Sep 17 00:00:00 2001
From: Toshiaki Kameyama <kmymtsak@gmail.com>
Date: Sun, 9 Oct 2022 20:48:37 +0900
Subject: [PATCH] Fix false negative MultilineLambdaItParameter on complex
 multiline single statement

---
 .../rules/style/MultilineLambdaItParameter.kt     |  6 ++++--
 .../rules/style/MultilineLambdaItParameterSpec.kt | 15 +++++++++++++++
 2 files changed, 19 insertions(+), 2 deletions(-)

diff --git a/detekt-rules-style/src/main/kotlin/io/gitlab/arturbosch/detekt/rules/style/MultilineLambdaItParameter.kt b/detekt-rules-style/src/main/kotlin/io/gitlab/arturbosch/detekt/rules/style/MultilineLambdaItParameter.kt
index 40d08f0131a..a493f2786e8 100644
--- a/detekt-rules-style/src/main/kotlin/io/gitlab/arturbosch/detekt/rules/style/MultilineLambdaItParameter.kt
+++ b/detekt-rules-style/src/main/kotlin/io/gitlab/arturbosch/detekt/rules/style/MultilineLambdaItParameter.kt
@@ -11,7 +11,9 @@ import io.gitlab.arturbosch.detekt.api.internal.RequiresTypeResolution
 import io.gitlab.arturbosch.detekt.rules.IT_LITERAL
 import io.gitlab.arturbosch.detekt.rules.hasImplicitParameterReference
 import io.gitlab.arturbosch.detekt.rules.implicitParameter
+import org.jetbrains.kotlin.psi.KtBlockExpression
 import org.jetbrains.kotlin.psi.KtLambdaExpression
+import org.jetbrains.kotlin.psi.psiUtil.collectDescendantsOfType
 
 /**
  * Lambda expressions are very useful in a lot of cases, and they often include very small chunks of
@@ -74,8 +76,8 @@ class MultilineLambdaItParameter(val config: Config) : Rule(config) {
 
     override fun visitLambdaExpression(lambdaExpression: KtLambdaExpression) {
         super.visitLambdaExpression(lambdaExpression)
-        val size = lambdaExpression.bodyExpression?.statements?.size
-        if (size == null || size <= 1) return
+        val size = lambdaExpression.collectDescendantsOfType<KtBlockExpression>().flatMap { it.statements }.size
+        if (size <= 1) return
 
         val parameterNames = lambdaExpression.valueParameters.map { it.name }
         // Explicit `it`
diff --git a/detekt-rules-style/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/style/MultilineLambdaItParameterSpec.kt b/detekt-rules-style/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/style/MultilineLambdaItParameterSpec.kt
index f60ad833601..21cff6dbac6 100644
--- a/detekt-rules-style/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/style/MultilineLambdaItParameterSpec.kt
+++ b/detekt-rules-style/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/style/MultilineLambdaItParameterSpec.kt
@@ -114,6 +114,21 @@ class MultilineLambdaItParameterSpec(val env: KotlinCoreEnvironment) {
             val findings = subject.compileAndLintWithContext(env, code)
             assertThat(findings).isEmpty()
         }
+
+        @Test
+        fun `reports when statement is spanning multiple lines`() {
+            val code = """
+            fun f() {
+                val digits = 1234.let {
+                    check(it > 0) {
+                        println(it)
+                    }
+                }
+            }
+            """.trimIndent()
+            val findings = subject.compileAndLintWithContext(env, code)
+            assertThat(findings).hasSize(1)
+        }
     }
 
     @Nested