kotlin-result/src/test/kotlin/com/github/michaelbull/result/AndTest.kt

package com.github.michaelbull.result

import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.assertSame

internal class AndTest {
    private object AndError

    internal class `and` {
        @Test
        internal fun returnsValueIfOk() {
            assertEquals(
                expected = 500,
                actual = Ok(230).and { Ok(500) }.get()
            )
        }

        @Test
        internal fun returnsValueIfErr() {
            assertEquals(
                expected = "hello world",
                actual = Ok(300).and { Err("hello world") }.getError()
            )
        }
    }

    internal class `andThen` {
        @Test
        internal fun returnsTransformedValueIfOk() {
            assertEquals(
                expected = 12,
                actual = Ok(5).andThen { Ok(it + 7) }.get()
            )
        }

        @Test
        internal fun returnsErrorIfErr() {
            assertSame(
                expected = AndError,
                actual = Ok(20).andThen { Ok(it + 43) }.andThen { Err(AndError) }.getError()!!
            )
        }
    }
}