From 7126e4ba3e1b40f55fad9b17af477f78fea67add Mon Sep 17 00:00:00 2001
From: Matthew Haughton <3flex@users.noreply.github.com>
Date: Tue, 8 Feb 2022 07:49:00 +1100
Subject: [PATCH] Migrate detekt-rules-performance tests to JUnit (#4569)

---
 detekt-rules-performance/build.gradle.kts     |   3 +-
 .../rules/performance/ArrayPrimitiveSpec.kt   | 158 ++++++++++++------
 .../rules/performance/ForEachOnRangeSpec.kt   |  31 ++--
 .../rules/performance/SpreadOperatorSpec.kt   |  82 +++++----
 .../UnnecessaryTemporaryInstantiationSpec.kt  |  19 ++-
 5 files changed, 191 insertions(+), 102 deletions(-)

diff --git a/detekt-rules-performance/build.gradle.kts b/detekt-rules-performance/build.gradle.kts
index 78e6820b8..e0469ce85 100644
--- a/detekt-rules-performance/build.gradle.kts
+++ b/detekt-rules-performance/build.gradle.kts
@@ -5,6 +5,5 @@ plugins {
 dependencies {
     compileOnly(projects.detektApi)
     testImplementation(projects.detektTest)
-    testImplementation(libs.bundles.testImplementation)
-    testRuntimeOnly(libs.spek.runner)
+    testImplementation(libs.assertj)
 }
diff --git a/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/ArrayPrimitiveSpec.kt b/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/ArrayPrimitiveSpec.kt
index ac59de62c..f5124439c 100644
--- a/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/ArrayPrimitiveSpec.kt
+++ b/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/ArrayPrimitiveSpec.kt
@@ -1,210 +1,266 @@
 package io.gitlab.arturbosch.detekt.rules.performance
 
-import io.gitlab.arturbosch.detekt.rules.setupKotlinEnvironment
+import io.gitlab.arturbosch.detekt.rules.KotlinCoreEnvironmentTest
 import io.gitlab.arturbosch.detekt.test.compileAndLint
 import io.gitlab.arturbosch.detekt.test.compileAndLintWithContext
 import org.assertj.core.api.Assertions.assertThat
 import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment
-import org.spekframework.spek2.Spek
-import org.spekframework.spek2.style.specification.describe
+import org.junit.jupiter.api.DisplayName
+import org.junit.jupiter.api.Nested
+import org.junit.jupiter.api.Test
 
-class ArrayPrimitiveSpec : Spek({
-    setupKotlinEnvironment()
+@KotlinCoreEnvironmentTest
+class ArrayPrimitiveSpec(val env: KotlinCoreEnvironment) {
 
-    val env: KotlinCoreEnvironment by memoized()
-    val subject by memoized { ArrayPrimitive() }
+    val subject = ArrayPrimitive()
 
-    describe("one function parameter") {
-        it("is an array of primitive type") {
+    @Nested
+    inner class `one function parameter` {
+        @Test
+        fun `is an array of primitive type`() {
             val code = "fun function(array: Array<Int>) {}"
             assertThat(subject.compileAndLint(code)).hasSize(1)
         }
 
-        it("is not an array") {
+        @Test
+        fun `is not an array`() {
             val code = "fun function(i: Int) {}"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
 
-        it("is a specialized array") {
+        @Test
+        fun `is a specialized array`() {
             val code = "fun function(array: ByteArray) {}"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
 
-        it("is a star-projected array") {
+        @Test
+        fun `is a star-projected array`() {
             val code = "fun function(array: Array<*>) {}"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
 
-        it("is not present") {
+        @Test
+        fun `is not present`() {
             val code = "fun function() {}"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
 
-        it("is an array of a non-primitive type") {
+        @Test
+        fun `is an array of a non-primitive type`() {
             val code = "fun function(array: Array<String>) {}"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
 
-        it("is an array of an array of a primitive type") {
+        @Test
+        fun `is an array of an array of a primitive type`() {
             val code = "fun function(array: Array<Array<Int>>) {}"
             assertThat(subject.compileAndLint(code)).hasSize(1)
         }
 
-        it("is a dictionary with an array of a primitive type as key") {
+        @Test
+        fun `is a dictionary with an array of a primitive type as key`() {
             val code = "fun function(dict: java.util.Dictionary<Int, Array<Int>>) {}"
             assertThat(subject.compileAndLint(code)).hasSize(1)
         }
     }
 
-    describe("multiple function parameters") {
-        it("one is Array<Primitive> and the other is not") {
+    @Nested
+    inner class `multiple function parameters` {
+        @Test
+        @DisplayName("one is Array<Primitive> and the other is not")
+        fun oneArrayPrimitive() {
             val code = "fun function(array: Array<Int>, array2: IntArray) {}"
             assertThat(subject.compileAndLint(code)).hasSize(1)
         }
 
-        it("both are arrays of primitive types") {
+        @Test
+        fun `both are arrays of primitive types`() {
             val code = "fun function(array: Array<Int>, array2: Array<Double>) {}"
             assertThat(subject.compileAndLint(code)).hasSize(2)
         }
     }
 
-    describe("return type") {
-        it("is Array<Primitive>") {
+    @Nested
+    inner class `return type` {
+        @Test
+        @DisplayName("is Array<Primitive>")
+        fun isArrayPrimitive() {
             val code = "fun returningFunction(): Array<Float> { return emptyArray() }"
             assertThat(subject.compileAndLint(code)).hasSize(1)
         }
 
-        it("is not an array") {
+        @Test
+        fun `is not an array`() {
             val code = "fun returningFunction(): Int { return 1 }"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
 
-        it("is a specialized array") {
+        @Test
+        fun `is a specialized array`() {
             val code = "fun returningFunction(): CharArray { return CharArray(0) }"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
 
-        it("is a star-projected array") {
+        @Test
+        fun `is a star-projected array`() {
             val code = "fun returningFunction(): Array<*> { return emptyArray<Any>() }"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
 
-        it("is not explicitly set") {
+        @Test
+        fun `is not explicitly set`() {
             val code = "fun returningFunction() {}"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
     }
 
-    describe("variable type") {
-        it("is Array<Primitive>") {
+    @Nested
+    inner class `variable type` {
+        @Test
+        @DisplayName("is Array<Primitive>")
+        fun isArrayPrimitive() {
             val code = "val foo: Array<Int>? = null"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
     }
 
-    describe("receiver type") {
-        it("is Array<Primitive>") {
+    @Nested
+    inner class `receiver type` {
+        @Test
+        @DisplayName("is Array<Primitive>")
+        fun isArrayPrimitive() {
             val code = "fun Array<Boolean>.foo() { println(this) }"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
     }
 
-    describe("arrayOf") {
-        it("is arrayOf(Char)") {
+    @Nested
+    inner class `arrayOf` {
+        @Test
+        fun `is arrayOf(Char)`() {
             val code = "fun foo(x: Char) = arrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is arrayOf(Byte)") {
+        @Test
+        fun `is arrayOf(Byte)`() {
             val code = "fun foo(x: Byte) = arrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is arrayOf(Short)") {
+        @Test
+        fun `is arrayOf(Short)`() {
             val code = "fun foo(x: Short) = arrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is arrayOf(Int)") {
+        @Test
+        fun `is arrayOf(Int)`() {
             val code = "fun foo(x: Int) = arrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is arrayOf(Long)") {
+        @Test
+        fun `is arrayOf(Long)`() {
             val code = "fun foo(x: Long) = arrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is arrayOf(Float)") {
+        @Test
+        fun `is arrayOf(Float)`() {
             val code = "fun foo(x: Float) = arrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is arrayOf(Double)") {
+        @Test
+        fun `is arrayOf(Double)`() {
             val code = "fun foo(x: Double) = arrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is arrayOf(Boolean)") {
+        @Test
+        fun `is arrayOf(Boolean)`() {
             val code = "fun foo(x: Boolean) = arrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is arrayOf(String)") {
+        @Test
+        fun `is arrayOf(String)`() {
             val code = "fun foo(x: String) = arrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
         }
 
-        it("is intArrayOf()") {
+        @Test
+        fun `is intArrayOf()`() {
             val code = "fun test(x: Int) = intArrayOf(x)"
             assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
         }
     }
 
-    describe("emptyArray") {
-        it("is emptyArray<Char>()") {
+    @Nested
+    inner class `emptyArray` {
+        @Test
+        @DisplayName("is emptyArray<Char>()")
+        fun isEmptyArrayChar() {
             val code = "val a = emptyArray<Char>()"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is emptyArray<Byte>()") {
+        @Test
+        @DisplayName("is emptyArray<Byte>()")
+        fun isEmptyArrayByte() {
             val code = "val a = emptyArray<Byte>()"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is emptyArray<Short>()") {
+        @Test
+        @DisplayName("is emptyArray<Short>()")
+        fun isEmptyArrayShort() {
             val code = "val a = emptyArray<Short>()"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is emptyArray<Int>()") {
+        @Test
+        @DisplayName("is emptyArray<Int>()")
+        fun isEmptyArrayInt() {
             val code = "val a = emptyArray<Int>()"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is emptyArray<Long>()") {
+        @Test
+        @DisplayName("is emptyArray<Long>()")
+        fun isEmptyArrayLong() {
             val code = "val a = emptyArray<Long>()"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is emptyArray<Float>()") {
+        @Test
+        @DisplayName("is emptyArray<Float>()")
+        fun isEmptyArrayFloat() {
             val code = "val a = emptyArray<Float>()"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is emptyArray<Double>()") {
+        @Test
+        @DisplayName("is emptyArray<Double>()")
+        fun isEmptyArrayDouble() {
             val code = "val a = emptyArray<Double>()"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is emptyArray<Boolean>()") {
+        @Test
+        @DisplayName("is emptyArray<Boolean>()")
+        fun isEmptyArrayBoolean() {
             val code = "val a = emptyArray<Boolean>()"
             assertThat(subject.compileAndLintWithContext(env, code)).hasSize(1)
         }
 
-        it("is emptyArray<String>()") {
+        @Test
+        @DisplayName("is emptyArray<String>()")
+        fun isEmptyArrayString() {
             val code = "val a = emptyArray<String>()"
             assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
         }
     }
-})
+}
diff --git a/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/ForEachOnRangeSpec.kt b/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/ForEachOnRangeSpec.kt
index 51d086fa1..43198b501 100644
--- a/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/ForEachOnRangeSpec.kt
+++ b/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/ForEachOnRangeSpec.kt
@@ -2,16 +2,18 @@ package io.gitlab.arturbosch.detekt.rules.performance
 
 import io.gitlab.arturbosch.detekt.test.compileAndLint
 import org.assertj.core.api.Assertions.assertThat
-import org.spekframework.spek2.Spek
-import org.spekframework.spek2.style.specification.describe
+import org.junit.jupiter.api.Nested
+import org.junit.jupiter.api.Test
 
-class ForEachOnRangeSpec : Spek({
+class ForEachOnRangeSpec {
 
-    val subject by memoized { ForEachOnRange() }
+    val subject = ForEachOnRange()
 
-    describe("ForEachOnRange rule") {
+    @Nested
+    inner class `ForEachOnRange rule` {
 
-        context("using a forEach on a range") {
+        @Nested
+        inner class `using a forEach on a range` {
             val code = """
             fun test() {
                 (1..10).forEach {
@@ -29,26 +31,30 @@ class ForEachOnRangeSpec : Spek({
             }
         """
 
-            it("should report the forEach usage") {
+            @Test
+            fun `should report the forEach usage`() {
                 val findings = subject.compileAndLint(code)
                 assertThat(findings).hasSize(4)
             }
         }
 
-        context("using any other method on a range") {
+        @Nested
+        inner class `using any other method on a range` {
             val code = """
             fun test() {
                 (1..10).isEmpty()
             }
         """
 
-            it("should not report any issues") {
+            @Test
+            fun `should not report any issues`() {
                 val findings = subject.compileAndLint(code)
                 assertThat(findings).isEmpty()
             }
         }
 
-        context("using a forEach on a list") {
+        @Nested
+        inner class `using a forEach on a list` {
             val code = """
             fun test() {
                 listOf(1, 2, 3).forEach {
@@ -57,10 +63,11 @@ class ForEachOnRangeSpec : Spek({
             }
         """
 
-            it("should not report any issues") {
+            @Test
+            fun `should not report any issues`() {
                 val findings = subject.compileAndLint(code)
                 assertThat(findings).isEmpty()
             }
         }
     }
-})
+}
diff --git a/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/SpreadOperatorSpec.kt b/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/SpreadOperatorSpec.kt
index 23ff9b6dd..6b0dc7df1 100644
--- a/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/SpreadOperatorSpec.kt
+++ b/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/SpreadOperatorSpec.kt
@@ -1,31 +1,33 @@
 package io.gitlab.arturbosch.detekt.rules.performance
 
-import io.gitlab.arturbosch.detekt.rules.setupKotlinEnvironment
+import io.gitlab.arturbosch.detekt.rules.KotlinCoreEnvironmentTest
 import io.gitlab.arturbosch.detekt.test.compileAndLint
 import io.gitlab.arturbosch.detekt.test.compileAndLintWithContext
 import org.assertj.core.api.Assertions.assertThat
 import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment
-import org.spekframework.spek2.Spek
-import org.spekframework.spek2.style.specification.describe
+import org.junit.jupiter.api.Nested
+import org.junit.jupiter.api.Test
 
-class SpreadOperatorSpec : Spek({
-    setupKotlinEnvironment()
+@KotlinCoreEnvironmentTest
+class SpreadOperatorSpec(val env: KotlinCoreEnvironment) {
 
-    val env: KotlinCoreEnvironment by memoized()
-    val subject by memoized { SpreadOperator() }
+    val subject = SpreadOperator()
 
-    describe("SpreadOperator rule") {
+    @Nested
+    inner class `SpreadOperator rule` {
         /**
          * This rule has different behaviour depending on whether type resolution is enabled in detekt or not. The two
          * `context` blocks are there to test behaviour when type resolution is enabled and type resolution is disabled
          * as different warning messages are shown in each case.
          */
-        context("with type resolution") {
+        @Nested
+        inner class `with type resolution` {
 
             val typeResolutionEnabledMessage = "Used in this way a spread operator causes a full copy of the array to" +
                 " be created before calling a method. This may result in a performance penalty."
 
-            it("reports when array copy required using named parameters") {
+            @Test
+            fun `reports when array copy required using named parameters`() {
                 val code = """
                     val xsArray = intArrayOf(1)
                     fun foo(vararg xs: Int) {}
@@ -35,7 +37,9 @@ class SpreadOperatorSpec : Spek({
                 assertThat(actual).hasSize(1)
                 assertThat(actual.first().message).isEqualTo(typeResolutionEnabledMessage)
             }
-            it("reports when array copy required without using named parameters") {
+
+            @Test
+            fun `reports when array copy required without using named parameters`() {
                 val code = """
                     val xsArray = intArrayOf(1)
                     fun foo(vararg xs: Int) {}
@@ -45,7 +49,9 @@ class SpreadOperatorSpec : Spek({
                 assertThat(actual).hasSize(1)
                 assertThat(actual.first().message).isEqualTo(typeResolutionEnabledMessage)
             }
-            it("doesn't report when using array constructor with spread operator") {
+
+            @Test
+            fun `doesn't report when using array constructor with spread operator`() {
                 val code = """
                     fun foo(vararg xs: Int) {}
                     val testVal = foo(xs = *intArrayOf(1))
@@ -53,7 +59,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
             }
 
-            it("doesn't report when using array constructor with spread operator when varargs parameter comes first") {
+            @Test
+            fun `doesn't report when using array constructor with spread operator when varargs parameter comes first`() {
                 val code = """
                     fun <T> asList(vararg ts: T, stringValue: String): List<Int> = listOf(1,2,3)
                     val list = asList(-1, 0, *arrayOf(1, 2, 3), 4, stringValue = "5")
@@ -61,7 +68,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
             }
 
-            it("doesn't report when passing values directly") {
+            @Test
+            fun `doesn't report when passing values directly`() {
                 val code = """
                     fun <T> asList(vararg ts: T, stringValue: String): List<Int> = listOf(1,2,3)
                     val list = asList(-1, 0, 1, 2, 3, 4, stringValue = "5")
@@ -69,7 +77,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
             }
 
-            it("doesn't report when function doesn't take a vararg parameter") {
+            @Test
+            fun `doesn't report when function doesn't take a vararg parameter`() {
                 val code = """
                 fun test0(strs: Array<String>) {
                     test(strs)
@@ -82,7 +91,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
             }
 
-            it("doesn't report with expression inside params") {
+            @Test
+            fun `doesn't report with expression inside params`() {
                 val code = """
                 fun test0(strs: Array<String>) {
                     test(2*2)
@@ -95,7 +105,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
             }
 
-            it("respects pass through of vararg parameter - #3145") {
+            @Test
+            fun `respects pass through of vararg parameter - #3145`() {
                 val code = """
                     fun b(vararg bla: Int) = Unit
                     fun a(vararg bla: Int) { 
@@ -105,7 +116,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLintWithContext(env, code)).isEmpty()
             }
 
-            it("reports shadowed vararg declaration which may lead to array copy - #3145") {
+            @Test
+            fun `reports shadowed vararg declaration which may lead to array copy - #3145`() {
                 val code = """
                     fun b(vararg bla: String) = Unit
 
@@ -118,12 +130,14 @@ class SpreadOperatorSpec : Spek({
             }
         }
 
-        context("without type resolution") {
+        @Nested
+        inner class `without type resolution` {
 
             val typeResolutionDisabledMessage = "In most cases using a spread operator causes a full copy of the " +
                 "array to be created before calling a method. This may result in a performance penalty."
 
-            it("reports when array copy required using named parameters") {
+            @Test
+            fun `reports when array copy required using named parameters`() {
                 val code = """
                     val xsArray = intArrayOf(1)
                     fun foo(vararg xs: Int) {}
@@ -133,7 +147,9 @@ class SpreadOperatorSpec : Spek({
                 assertThat(actual).hasSize(1)
                 assertThat(actual.first().message).isEqualTo(typeResolutionDisabledMessage)
             }
-            it("reports when array copy required without using named parameters") {
+
+            @Test
+            fun `reports when array copy required without using named parameters`() {
                 val code = """
                     val xsArray = intArrayOf(1)
                     fun foo(vararg xs: Int) {}
@@ -143,7 +159,9 @@ class SpreadOperatorSpec : Spek({
                 assertThat(actual).hasSize(1)
                 assertThat(actual.first().message).isEqualTo(typeResolutionDisabledMessage)
             }
-            it("doesn't report when using array constructor with spread operator") {
+
+            @Test
+            fun `doesn't report when using array constructor with spread operator`() {
                 val code = """
                     fun foo(vararg xs: Int) {}
                     val testVal = foo(xs = *intArrayOf(1))
@@ -153,7 +171,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(actual.first().message).isEqualTo(typeResolutionDisabledMessage)
             }
 
-            it("doesn't report when using array constructor with spread operator when varargs parameter comes first") {
+            @Test
+            fun `doesn't report when using array constructor with spread operator when varargs parameter comes first`() {
                 val code = """
                     fun <T> asList(vararg ts: T, stringValue: String): List<Int> = listOf(1,2,3)
                     val list = asList(-1, 0, *arrayOf(1, 2, 3), 4, stringValue = "5")
@@ -163,7 +182,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(actual.first().message).isEqualTo(typeResolutionDisabledMessage)
             }
 
-            it("doesn't report when passing values directly") {
+            @Test
+            fun `doesn't report when passing values directly`() {
                 val code = """
                     fun <T> asList(vararg ts: T, stringValue: String): List<Int> = listOf(1,2,3)
                     val list = asList(-1, 0, 1, 2, 3, 4, stringValue = "5")
@@ -171,7 +191,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLint(code)).isEmpty()
             }
 
-            it("doesn't report when function doesn't take a vararg parameter") {
+            @Test
+            fun `doesn't report when function doesn't take a vararg parameter`() {
                 val code = """
                 fun test0(strs: Array<String>) {
                     test(strs)
@@ -184,7 +205,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLint(code)).isEmpty()
             }
 
-            it("doesn't report with expression inside params") {
+            @Test
+            fun `doesn't report with expression inside params`() {
                 val code = """
                 fun test0(strs: Array<String>) {
                     test(2*2)
@@ -197,7 +219,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLint(code)).isEmpty()
             }
 
-            it("respects pass through of vararg parameter - #3145") {
+            @Test
+            fun `respects pass through of vararg parameter - #3145`() {
                 val code = """
                     fun b(vararg bla: Int) = Unit
                     fun a(vararg bla: Int) { 
@@ -207,7 +230,8 @@ class SpreadOperatorSpec : Spek({
                 assertThat(subject.compileAndLint(code)).isEmpty()
             }
 
-            it("does not report shadowed vararg declaration, we except this false negative here - #3145") {
+            @Test
+            fun `does not report shadowed vararg declaration, we except this false negative here - #3145`() {
                 val code = """
                     fun b(vararg bla: String) = Unit
 
@@ -220,4 +244,4 @@ class SpreadOperatorSpec : Spek({
             }
         }
     }
-})
+}
diff --git a/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/UnnecessaryTemporaryInstantiationSpec.kt b/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/UnnecessaryTemporaryInstantiationSpec.kt
index a3e9ee272..f82c70b7f 100644
--- a/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/UnnecessaryTemporaryInstantiationSpec.kt
+++ b/detekt-rules-performance/src/test/kotlin/io/gitlab/arturbosch/detekt/rules/performance/UnnecessaryTemporaryInstantiationSpec.kt
@@ -2,22 +2,25 @@ package io.gitlab.arturbosch.detekt.rules.performance
 
 import io.gitlab.arturbosch.detekt.test.compileAndLint
 import org.assertj.core.api.Assertions.assertThat
-import org.spekframework.spek2.Spek
-import org.spekframework.spek2.style.specification.describe
+import org.junit.jupiter.api.Nested
+import org.junit.jupiter.api.Test
 
-class UnnecessaryTemporaryInstantiationSpec : Spek({
-    val subject by memoized { UnnecessaryTemporaryInstantiation() }
+class UnnecessaryTemporaryInstantiationSpec {
+    val subject = UnnecessaryTemporaryInstantiation()
 
-    describe("UnnecessaryTemporaryInstantiation rule") {
+    @Nested
+    inner class `UnnecessaryTemporaryInstantiation rule` {
 
-        it("temporary instantiation for conversion") {
+        @Test
+        fun `temporary instantiation for conversion`() {
             val code = "val i = Integer(1).toString()"
             assertThat(subject.compileAndLint(code)).hasSize(1)
         }
 
-        it("right conversion without instantiation") {
+        @Test
+        fun `right conversion without instantiation`() {
             val code = "val i = Integer.toString(1)"
             assertThat(subject.compileAndLint(code)).isEmpty()
         }
     }
-})
+}