UnusedImportsSpec.kt

package io.gitlab.arturbosch.detekt.rules.style

import io.gitlab.arturbosch.detekt.api.Config
import io.gitlab.arturbosch.detekt.rules.KotlinCoreEnvironmentTest
import io.gitlab.arturbosch.detekt.test.lintWithContext
import org.assertj.core.api.Assertions.assertThat
import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment
import org.junit.jupiter.api.Test

@KotlinCoreEnvironmentTest
class UnusedImportsSpec(val env: KotlinCoreEnvironment) {
    val subject = UnusedImports(Config.empty)

    @Test
    fun `does not report infix operators`() {
        val main = """
            import tasks.success

            fun task(f: () -> Unit) = 1

            fun main() {
                task {
                } success {
                }
            }
        """
        val additional = """
            package tasks

            infix fun Int.success(f: () -> Unit) {}
        """
        assertThat(subject.lintWithContext(env, main, additional)).isEmpty()
    }

    @Test
    fun `does not report imports in documentation`() {
        val main = """
            import tasks.success
            import tasks.failure
            import tasks.undefined

            fun task(f: () -> Unit) = 1

            /**
             *  Reference to [failure]
             */
            class Test {
                /** Reference to [undefined]*/
                fun main() {
                    task {
                    } success {
                    }
                }
            }
        """
        val additional = """
            package tasks

            infix fun Int.success(f: () -> Unit) {}
            infix fun Int.failure(f: () -> Unit) {}
            infix fun Int.undefined(f: () -> Unit) {}
        """
        assertThat(subject.lintWithContext(env, main, additional)).isEmpty()
    }

    @Test
    fun `should ignore import for link`() {
        val main = """
            import tasks.success
            import tasks.failure
            import tasks.undefined

            fun task(f: () -> Unit) = 1

            /**
             * Reference [undefined][failure]
             */
            fun main() {
                task {
                } success {
                }
            }                
        """
        val additional = """
            package tasks
            
            infix fun Int.success(f: () -> Unit) {}
            infix fun Int.failure(f: () -> Unit) {}
            infix fun Int.undefined(f: () -> Unit) {}
        """
        val lint = subject.lintWithContext(env, main, additional)
        with(lint) {
            assertThat(this).hasSize(1)
            assertThat(this[0].entity.signature).endsWith("import tasks.undefined")
        }
    }

    @Test
    fun `reports imports from the current package`() {
        val main = """
            package test
            import test.SomeClass

            val a: SomeClass? = null
        """
        val additional = """
            package test

            class SomeClass
        """
        val lint = subject.lintWithContext(env, main, additional)
        with(lint) {
            assertThat(this).hasSize(1)
            assertThat(this[0].entity.signature).endsWith("import test.SomeClass")
        }
    }

    @Test
    fun `does not report KDoc references with method calls`() {
        val main = """
            package com.example

            import android.text.TextWatcher

            class Test {
                /**
                 * [TextWatcher.beforeTextChanged]
                 */
                fun test() {
                    TODO()
                }
            }
        """
        val additional = """
            package android.text

            class TextWatcher {
                fun beforeTextChanged() {}
            }                
        """
        assertThat(subject.lintWithContext(env, main, additional)).isEmpty()
    }

    @Test
    fun `reports imports with different cases`() {
        val main = """
            import p.a
            import p.B6 // positive
            import p.B as B12 // positive
            import p2.B as B2
            import p.C
            import escaped.`when`
            import escaped.`foo` // positive
            import p.D

            /** reference to [D] */
            fun main() {
                println(a())
                C.call()
                fn(B2.NAME)
                `when`()
            }

            fun fn(s: String) {}
        """
        val p = """
            package p

            fun a() {}
            class B6
            class B
            object C {
                fun call() {}
            }
            class D
        """
        val p2 = """
            package p2

            object B {
                const val NAME = ""
            }
        """
        val escaped = """
            package escaped

            fun `when`() {}
            fun `foo`() {}
        """
        val lint = subject.lintWithContext(env, main, p, p2, escaped)
        with(lint) {
            assertThat(this).hasSize(3)
            assertThat(this[0].entity.signature).contains("import p.B6")
            assertThat(this[1].entity.signature).contains("import p.B as B12")
            assertThat(this[2].entity.signature).contains("import escaped.`foo`")
        }
    }

    @Test
    fun `does not report imports in same package when inner`() {
        val main = """
            package test
            
            import test.Outer.Inner
            
            open class Something<T>
            
            class Foo : Something<Inner>()                
        """
        val additional = """
            package test
            
            class Outer {
                class Inner
            }
        """
        val lint = subject.lintWithContext(env, main, additional)
        with(lint) {
            assertThat(this).isEmpty()
        }
    }

    @Test
    fun `does not report KDoc @see annotation linking to class`() {
        val main = """
            import tasks.success

            /**
             * Do something.
             * @see success
             */
            fun doSomething()
        """
        val additional = """
            package tasks

            fun success() {}
        """
        assertThat(subject.lintWithContext(env, main, additional)).isEmpty()
    }

    @Test
    fun `does not report KDoc @see annotation linking to class with description`() {
        val main = """
            import tasks.success

            /**
             * Do something.
             * @see success something
             */
            fun doSomething() {}
        """
        val additional = """
            package tasks

            fun success() {}
        """
        assertThat(subject.lintWithContext(env, main, additional)).isEmpty()
    }

    @Test
    fun `reports KDoc @see annotation that does not link to class`() {
        val main = """
            import tasks.success

            /**
             * Do something.
             * @see something
             */
            fun doSomething() {}
        """
        val additional = """
            package tasks

            fun success() {}
        """
        assertThat(subject.lintWithContext(env, main, additional)).hasSize(1)
    }

    @Test
    fun `reports KDoc @see annotation that links after description`() {
        val main = """
            import tasks.success

            /**
             * Do something.
             * @see something success
             */
            fun doSomething() {}
        """
        val additional = """
            package tasks

            fun success() {}
        """
        assertThat(subject.lintWithContext(env, main, additional)).hasSize(1)
    }

    @Test
    fun `does not report imports in KDoc`() {
        val main = """
            import tasks.success   // here
            import tasks.undefined // and here

            /**
             * Do something.
             * @throws success when ...
             * @exception success when ...
             * @see undefined
             * @sample success when ...
             */
            fun doSomething() {}
        """
        val additional = """
            package tasks

            fun success() {}
            fun undefined() {}
        """
        assertThat(subject.lintWithContext(env, main, additional)).isEmpty()
    }

    @Test
    fun `should not report import alias as unused when the alias is used`() {
        val main = """
            import test.forEach as foreach
            fun foo() = listOf().iterator().foreach {}
        """
        val additional = """
            package test
            fun Iterator<Int>.forEach(f: () -> Unit) {}
        """
        assertThat(subject.lintWithContext(env, main, additional)).isEmpty()
    }

    @Test
    fun `should not report used alias even when import is from same package`() {
        val main = """
            package com.example

            import com.example.foo as myFoo // from same package but with alias, check alias usage
            import com.example.other.foo as otherFoo // not from package with used alias

            fun f(): Boolean {
                return myFoo() == otherFoo()
            }
        """
        val additional1 = """
            package com.example
            fun foo() = 1                
        """
        val additional2 = """
            package com.example.other
            fun foo() = 1                
        """
        assertThat(subject.lintWithContext(env, main, additional1, additional2)).isEmpty()
    }

    @Test
    fun `should not report import of provideDelegate operator overload - #1608`() {
        val main = """
            import org.gradle.kotlin.dsl.Foo
            import org.gradle.kotlin.dsl.provideDelegate // this line specifically should not be reported
            
            class DumpVersionProperties {
                private val dumpVersionProperties by Foo()
            }                
        """
        val additional = """
            package org.gradle.kotlin.dsl
            
            import kotlin.reflect.KProperty
            
            class Foo
            
            operator fun <T> Foo.provideDelegate(
                thisRef: T,
                prop: KProperty<*>
            ) = lazy { "" }                
        """
        assertThat(subject.lintWithContext(env, main, additional)).isEmpty()
    }

    @Test
    fun `should not report import of componentN operator`() {
        val main = """
            import com.example.MyClass.component1
            import com.example.MyClass.component2
            import com.example.MyClass.component543

            fun test() {
                val (a, b) = MyClass(1, 2)
            }
        """
        val additional = """
            package com.example
            data class MyClass(val a: Int, val b: Int)                
        """

        assertThat(subject.lintWithContext(env, main, additional)).isEmpty()
    }

    @Test
    fun `should report import of identifiers with component in the name`() {
        val main = """
            import com.example.TestComponent
            import com.example.component1.Unused
            import com.example.components
            import com.example.component1AndSomethingElse

            fun test() {
                println("Testing")
            }
        """
        val additional1 = """
            package com.example
            class TestComponent
            fun components() {}
            fun component1AndSomethingElse() {}
        """
        val additional2 = """
            package com.example.component1
            class Unused
        """
        val lint = subject.lintWithContext(env, main, additional1, additional2)

        with(lint) {
            assertThat(this).hasSize(4)
            assertThat(this[0].entity.signature).endsWith("import com.example.TestComponent")
            assertThat(this[1].entity.signature).endsWith("import com.example.component1.Unused")
            assertThat(this[2].entity.signature).endsWith("import com.example.components")
            assertThat(this[3].entity.signature).endsWith("import com.example.component1AndSomethingElse")
        }
    }

    @Test
    fun `reports when same name identifiers are imported and used`() {
        val mainFile = """
            import foo.test
            import bar.test
            fun main() {
                test(1)
            }      
        """
        val additionalFile1 = """
            package foo
            fun test(i: Int) {}
        """
        val additionalFile2 = """
            package bar
            fun test(s: String) {}
        """
        val findings = subject.lintWithContext(env, mainFile, additionalFile1, additionalFile2)
        assertThat(findings).hasSize(1)
        assertThat(findings[0].entity.signature).endsWith("import bar.test")
    }

    @Test
    fun `does not report when used as a type`() {
        val code = """
            import java.util.HashMap
            
            fun doesNothing(thing: HashMap<String, String>) {
            }
        """
        val findings = subject.lintWithContext(env, code)
        assertThat(findings).isEmpty()
    }

    @Test
    fun `does not report when used in a class literal expression`() {
        val code = """
            import java.util.HashMap
            import kotlin.reflect.KClass
            
            annotation class Ann(val value: KClass<*>)
            
            @Ann(HashMap::class)
            fun foo() {}
        """
        val findings = subject.lintWithContext(env, code)
        assertThat(findings).isEmpty()
    }

    @Test
    fun `does not report when used as a constructor call`() {
        val mainFile = """
            import x.y.z.Foo
            
            val foo = Foo()
        """
        val additionalFile = """
            package x.y.z
            
            class Foo
        """
        val findings = subject.lintWithContext(env, mainFile, additionalFile)
        assertThat(findings).isEmpty()
    }

    @Test
    fun `does not report when used as a annotation`() {
        val mainFile = """
            import x.y.z.Ann

            @Ann
            fun foo() {}
        """
        val additionalFile = """
            package x.y.z
            
            annotation class Ann
        """
        val findings = subject.lintWithContext(env, mainFile, additionalFile)
        assertThat(findings).isEmpty()
    }

    @Test
    fun `does not report companion object`() {
        val mainFile = """
            import x.y.z.Foo
            
            val x = Foo
        """
        val additionalFile = """
            package x.y.z
            
            class Foo {
                companion object
            }
        """
        val findings = subject.lintWithContext(env, mainFile, additionalFile)
        assertThat(findings).isEmpty()
    }

    @Test
    fun `does not report companion object that calls function`() {
        val mainFile = """
            import x.y.z.Foo
            
            val x = Foo.create()
        """
        val additionalFile = """
            package x.y.z
            
            class Foo {
                companion object {
                    fun create(): Foo = Foo()
                }
            }
        """
        val findings = subject.lintWithContext(env, mainFile, additionalFile)
        assertThat(findings).isEmpty()
    }

    @Test
    fun `does not report companion object that references variable`() {
        val mainFile = """
            import x.y.z.Foo
            
            val x = Foo.BAR
        """
        val additionalFile = """
            package x.y.z
            
            class Foo {
                companion object {
                    const val BAR = 1
                }
            }
        """
        val findings = subject.lintWithContext(env, mainFile, additionalFile)
        assertThat(findings).isEmpty()
    }

    @Test
    fun `does not report static import`() {
        val mainFile = """
            import x.y.z.FetchType
            
            val x = FetchType.LAZY
        """
        val additionalFile = """
            package x.y.z
            
            enum class FetchType {
                LAZY
            }
        """
        assertThat(subject.lintWithContext(env, mainFile, additionalFile)).isEmpty()
    }

    @Test
    fun `does not report annotations used as attributes - #3246`() {
        val mainFile = """
            import x.y.z.AnnotationA
            import x.y.z.AnnotationB
            
            class SomeClass {
                @AnnotationB(attribute = AnnotationA())
                val someProp: Int = 42
            }
        """
        val additionalFile = """
            package x.y.z
            
            annotation class AnnotationA
            annotation class AnnotationB(val attribute: AnnotationA)
        """
        assertThat(subject.lintWithContext(env, mainFile, additionalFile)).isEmpty()
    }

    @Test
    fun `does not report unused import for import used in kdoc - #4815`() {
        val mainFile = """
        import x.y.z.SomeClass

        class MyView

        /**
         * Style for [MyView]
         * Blablabla
         * 
         * @property someVal Someval for [SomeClass]
         */
         data class StyleClass(val someVal: String)
        """

        val additionalFile = """
        package x.y.z

        class SomeClass
        """

        assertThat(subject.lintWithContext(env, mainFile, additionalFile)).isEmpty()
    }
}