Assertions.kt

/*
 * Copyright 2024-2025 Kazimierz Pogoda / Xemantic
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     https://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

package com.xemantic.kotlin.test

import kotlin.contracts.ExperimentalContracts
import kotlin.contracts.InvocationKind
import kotlin.contracts.contract
import kotlin.reflect.typeOf
import kotlin.test.assertNotNull
import kotlin.test.assertTrue
import kotlin.test.asserter

@OptIn(ExperimentalContracts::class)
public fun assert(actual: Boolean, message: String? = null) {
    contract {
        returns() implies actual
    }
    return asserter.assertTrue(message ?: "Expected value to be true.", actual)
}

@OptIn(ExperimentalContracts::class)
public infix fun <T> T?.should(block: T.() -> Unit) {
    contract {
        callsInPlace(block, InvocationKind.EXACTLY_ONCE)
    }
    assertNotNull(this)
    try {
        block()
    } catch (e: AssertionError) {
        throw ShouldAssertionError(
            message = if (e is ShouldAssertionError) {
                "$this\n containing:\n${e.message}"
            } else {
                "$this\n should:${e.message}"
            },
            cause = e
        )
    }
}

@OptIn(ExperimentalContracts::class)
public inline fun <reified T> Any?.be() {
    contract {
        returns() implies (this@be is T)
    }
    if (this !is T) {
        throw AssertionError(
            " be of type <${typeOf<T>()}>, actual <${this!!::class}>"
        )
    }
}

public fun have(
    condition: Boolean,
    message: String? = null
) {
    assertTrue(condition, message)
}

public class ShouldAssertionError(
    message: String,
    cause: AssertionError
) : AssertionError(message, cause)