NSInputStreamSourceTest.kt

/*
 * Copyright 2017-2023 JetBrains s.r.o. and respective authors and developers.
 * Use of this source code is governed by the Apache 2.0 license that can be found in the LICENCE file.
 */

package kotlinx.io

import platform.Foundation.NSInputStream
import kotlin.test.Test
import kotlin.test.assertEquals
import kotlin.test.fail

private const val SEGMENT_SIZE = Segment.SIZE

class NSInputStreamSourceTest {
    @Test
    fun nsInputStreamSource() {
        val nsis = NSInputStream(byteArrayOf(0x61).toNSData())
        val source = nsis.asSource()
        val buffer = Buffer()
        source.readAtMostTo(buffer, 1)
        assertEquals("a", buffer.readString())
    }

    @Test
    fun sourceFromInputStream() {
        val nsis = NSInputStream(
            ("a" + "b".repeat(SEGMENT_SIZE * 2) + "c").encodeToByteArray().toNSData(),
        )

        // Source: ab...bc
        val source: RawSource = nsis.asSource()
        val sink = Buffer()

        // Source: b...bc. Sink: abb.
        assertEquals(3, source.readAtMostTo(sink, 3))
        assertEquals("abb", sink.readString(3))

        // Source: b...bc. Sink: b...b.
        assertEquals(SEGMENT_SIZE.toLong(), source.readAtMostTo(sink, 20000))
        assertEquals("b".repeat(SEGMENT_SIZE), sink.readString())

        // Source: b...bc. Sink: b...bc.
        assertEquals((SEGMENT_SIZE - 1).toLong(), source.readAtMostTo(sink, 20000))
        assertEquals("b".repeat(SEGMENT_SIZE - 2) + "c", sink.readString())

        // Source and sink are empty.
        assertEquals(-1, source.readAtMostTo(sink, 1))
    }

    @Test
    fun sourceFromInputStreamWithSegmentSize() {
        val nsis = NSInputStream(ByteArray(SEGMENT_SIZE).toNSData())
        val source = nsis.asSource()
        val sink = Buffer()

        assertEquals(SEGMENT_SIZE.toLong(), source.readAtMostTo(sink, SEGMENT_SIZE.toLong()))
        assertEquals(-1, source.readAtMostTo(sink, SEGMENT_SIZE.toLong()))

        assertNoEmptySegments(sink)
    }

    @Test
    fun sourceFromInputStreamBounds() {
        val source = NSInputStream(ByteArray(100).toNSData()).asSource()
        try {
            source.readAtMostTo(Buffer(), -1)
            fail()
        } catch (expected: IllegalArgumentException) {
            // expected
        }
    }
}