forked from detekt/detekt
/
MultilineLambdaItParameterSpec.kt
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/
MultilineLambdaItParameterSpec.kt
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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.compileAndLintWithContext
import org.assertj.core.api.Assertions.assertThat
import org.jetbrains.kotlin.cli.jvm.compiler.KotlinCoreEnvironment
import org.junit.jupiter.api.Nested
import org.junit.jupiter.api.Test
@KotlinCoreEnvironmentTest
class MultilineLambdaItParameterSpec(val env: KotlinCoreEnvironment) {
val subject = MultilineLambdaItParameter(Config.empty)
@Nested
inner class `single parameter, multiline lambda with multiple statements` {
@Test
fun `reports when parameter name is implicit 'it'`() {
val code = """
fun f() {
val digits = 1234.let {
listOf(it)
println(it)
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).hasSize(1)
}
@Test
fun `reports when parameter name is explicit 'it'`() {
val code = """
fun f() {
val digits = 1234.let { it ->
listOf(it)
println(it)
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).hasSize(1)
}
@Test
fun `does not report when parameter name is explicit and not 'it'`() {
val code = """
fun f() {
val digits = 1234.let { param ->
listOf(param)
println(param)
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
@Test
fun `does not report when lambda has no implicit parameter references`() {
val code = """
fun foo(f: (Int) -> Unit) {}
fun main() {
foo {
println(1)
println(2)
val it = 3
println(it)
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
}
@Nested
inner class `single parameter, multiline lambda with a single statement` {
@Test
fun `does not report when parameter name is an implicit 'it'`() {
val code = """
fun f() {
val digits = 1234.let {
listOf(it)
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
@Test
fun `does not report when parameter name is an explicit 'it'`() {
val code = """
fun f() {
val digits = 1234.let { it ->
listOf(it)
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
@Test
fun `does not report when parameter name is explicit and not 'it'`() {
val code = """
fun f() {
val digits = 1234.let { param ->
listOf(param)
}
}
""".trimIndent()
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)
}
@Test
fun `does not report when statement has no nested statements`() {
val code = """
data class Foo(val x: Int, val y: Int)
fun f(i: Int?) {
val foo = i?.let {
Foo(
x = it,
y = 2
)
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
}
@Nested
inner class `single parameter, single-line lambda` {
@Test
fun `does not report when parameter name is an implicit 'it' with type resolution`() {
val code = """
fun f() {
val digits = 1234.let { listOf(it) }
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
@Test
fun `does not report when parameter name is an implicit 'it'`() {
val code = """
fun f() {
val digits = 1234.let { listOf(it) }
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
@Test
fun `does not report when parameter name is an explicit 'it'`() {
val code = """
fun f() {
val digits = 1234.let { it -> listOf(it) }
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
@Test
fun `does not report when parameter name is explicit and not 'it'`() {
val code = """
fun f() {
val digits = 1234.let { param -> listOf(param) }
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
@Test
fun `does not report when statement has one-line lambda argument`() {
val code = """
fun f() {
val digits = 1234.let {
check(it > 0) { println(it) }
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
}
@Nested
inner class `multiple parameters, multiline lambda` {
@Test
fun `reports when one of the explicit parameters is an 'it'`() {
val code = """
fun f() {
val flat = listOf(listOf(1), listOf(2)).mapIndexed { index, it ->
println(it)
it + index
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).hasSize(1)
}
@Test
fun `does not report when none of the explicit parameters is an 'it'`() {
val code = """
fun f() {
val lambda = { item: Int, that: String ->
println(item)
item.toString() + that
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
}
@Nested
inner class `no parameter, multiline lambda with multiple statements` {
@Test
fun `does not report when there is no parameter`() {
val code = """
fun f() {
val string = StringBuilder().apply {
append("a")
append("b")
}
}
""".trimIndent()
val findings = subject.compileAndLintWithContext(env, code)
assertThat(findings).isEmpty()
}
}
}