[android] Add test for MarkEnforcingInputStream

briar-android/src/test/java/org/briarproject/briar/android/conversation/MarkEnforcingInputStreamTest.java

@@ -0,0 +1,77 @@
+package org.briarproject.briar.android.conversation;
+
+import com.bumptech.glide.util.MarkEnforcingInputStream;
+
+import org.briarproject.bramble.test.BrambleTestCase;
+import org.junit.Test;
+
+import java.io.BufferedInputStream;
+import java.io.ByteArrayInputStream;
+import java.io.InputStream;
+
+import static org.junit.Assert.assertEquals;
+import static org.junit.Assert.assertNotEquals;
+
+public class MarkEnforcingInputStreamTest extends BrambleTestCase {
+
+	private final int readLimit = 4;
+	private final byte[] bytes = {0x1, 0x2, 0x3, 0x4, 0x5, 0x6};
+
+	@Test
+	public void testPlainStreamReadsAllBytes() throws Exception {
+		InputStream is = getStream();
+		is.mark(readLimit);
+		for (byte ignored : bytes) {
+			assertNotEquals(-1, is.read());
+		}
+		assertEquals(0, is.available());
+		is.close();
+	}
+
+	@Test
+	public void testMarkEnforcingStreamReadsUntilMarkLimit() throws Exception {
+		InputStream is = new MarkEnforcingInputStream(getStream());
+		is.mark(readLimit);
+		assertEquals(readLimit, is.available());
+		for (int i = 0; i < bytes.length; i++) {
+			if (i < readLimit) {
+				assertEquals(readLimit - i, is.available());
+				assertNotEquals(-1, is.read());
+			} else {
+				assertEquals(0, is.available());
+				assertEquals(-1, is.read());
+			}
+		}
+		assertEquals(0, is.available());
+		is.close();
+	}
+
+	@Test
+	public void testMarkEnforcingStreamCanBeReset() throws Exception {
+		InputStream is = new MarkEnforcingInputStream(getStream());
+		is.mark(readLimit);
+		assertEquals(readLimit, is.available());
+		for (int i = 0; i < readLimit; i++) {
+			assertNotEquals(-1, is.read());
+		}
+		assertEquals(0, is.available());
+		is.reset();
+		is.mark(readLimit);
+		assertEquals(readLimit, is.available());
+		for (int i = 0; i < bytes.length; i++) {
+			if (i < readLimit) {
+				assertEquals(readLimit - i, is.available());
+				assertNotEquals(-1, is.read());
+			} else {
+				assertEquals(0, is.available());
+				assertEquals(-1, is.read());
+			}
+		}
+		is.close();
+	}
+
+	private InputStream getStream() {
+		return new BufferedInputStream(new ByteArrayInputStream(bytes));
+	}
+
+}