From a43bc03f7d04efbd6a3a1d4f9d4e53cd41874dd2 Mon Sep 17 00:00:00 2001
From: Dominic Zirbel <dominiczirbel@gmail.com>
Date: Thu, 26 May 2022 12:26:42 -0700
Subject: [PATCH] UnnecessaryInnerClass: add test for safe qualified
 expressions

Add a unit test for a bug in which safe qualified references to a nullable field
in the parent class (i.e. as `?.`) would not be marked as warnings in release
1.20.0. This issue has been inadvertently fixed by
https://github.com/detekt/detekt/pull/4738, but adding a unit test will guard
against future regressions.

I was able to confirm this test fails by checking out the 1.20.0 tag and running
the unit test; against that tag the fix was to override the
visitSafeQualifiedExpression() function with the same logic as
visitCallExpression().
---
 .../rules/style/UnnecessaryInnerClassSpec.kt    | 17 +++++++++++++++++
 1 file changed, 17 insertions(+)

diff --git a/detekt-rules-style/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/style/UnnecessaryInnerClassSpec.kt b/detekt-rules-style/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/style/UnnecessaryInnerClassSpec.kt
index a20068ddcf4..e3f6d02cc6a 100644
--- a/detekt-rules-style/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/style/UnnecessaryInnerClassSpec.kt
+++ b/detekt-rules-style/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/style/UnnecessaryInnerClassSpec.kt
@@ -274,6 +274,23 @@ class UnnecessaryInnerClassSpec(val env: KotlinCoreEnvironment) {
             assertThat(subject.lintWithContext(env, code)).isEmpty()
         }
 
+        @Test
+        fun `as a safe qualified expression`() {
+            val code = """
+                class A {
+                    var foo: String? = null
+
+                    inner class B {
+                        fun fooLength() {
+                            foo?.length
+                        }
+                    }
+                }
+            """.trimIndent()
+
+            assertThat(subject.lintWithContext(env, code)).isEmpty()
+        }
+
         @Test
         fun `to call a function of the member`() {
             val code = """