chapter09 unit testing

chapter09-unit-testing/build.gradle.kts

@@ -0,0 +1,21 @@
+plugins {
+    id("java-conventions")
+}
+
+dependencies {
+    implementation(project(":core"))
+
+    implementation(platform(libs.netty.bom))
+    implementation("io.netty:netty-all")
+
+    testImplementation(platform(libs.junit.bom))
+    testImplementation("org.junit.jupiter:junit-jupiter")
+}
+
+tasks.test {
+    useJUnitPlatform()
+
+    testLogging {
+        showStandardStreams = true
+    }
+}

chapter09-unit-testing/src/main/java/com/joebrothers/chapter09/AbsIntegerEncoder.java

@@ -0,0 +1,18 @@
+package com.joebrothers.chapter09;
+
+import java.util.List;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.MessageToMessageEncoder;
+
+public class AbsIntegerEncoder extends MessageToMessageEncoder<ByteBuf> {
+    @Override
+    protected void encode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out)
+            throws Exception {
+        while (in.readableBytes() >= 4) {
+            final int value = Math.abs(in.readInt());
+            out.add(value);
+        }
+    }
+}

chapter09-unit-testing/src/main/java/com/joebrothers/chapter09/FixedLengthFrameDecoder.java

@@ -0,0 +1,29 @@
+package com.joebrothers.chapter09;
+
+import java.util.List;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.ByteToMessageDecoder;
+
+public class FixedLengthFrameDecoder extends ByteToMessageDecoder {
+
+    private final int frameLength;
+
+    public FixedLengthFrameDecoder(int frameLength) {
+        if (frameLength <= 0) {
+            throw new IllegalArgumentException("frameLength must be a positive integer: " + frameLength);
+        }
+
+        this.frameLength = frameLength;
+    }
+
+    @Override
+    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out)
+            throws Exception {
+        while (in.readableBytes() >= frameLength) {
+            final ByteBuf buf = in.readBytes(frameLength);
+            out.add(buf);
+        }
+    }
+}

chapter09-unit-testing/src/main/java/com/joebrothers/chapter09/FrameChunkDecoder.java

@@ -0,0 +1,34 @@
+package com.joebrothers.chapter09;
+
+import java.util.List;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.channel.ChannelHandlerContext;
+import io.netty.handler.codec.ByteToMessageDecoder;
+import io.netty.handler.codec.TooLongFrameException;
+
+public class FrameChunkDecoder extends ByteToMessageDecoder {
+
+    private final int maxFrameSize;
+
+    public FrameChunkDecoder(int maxFrameSize) {
+        if (maxFrameSize <= 0) {
+            throw new IllegalArgumentException("maxFrameSize must be a positive number: " + maxFrameSize);
+        }
+
+        this.maxFrameSize = maxFrameSize;
+    }
+
+    @Override
+    protected void decode(ChannelHandlerContext ctx, ByteBuf in, List<Object> out)
+            throws Exception {
+        final int readableBytes = in.readableBytes();
+        if (readableBytes > maxFrameSize) {
+            // discard
+            in.clear();
+            throw new TooLongFrameException();
+        }
+        final ByteBuf buf = in.readBytes(readableBytes);
+        out.add(buf);
+    }
+}

chapter09-unit-testing/src/test/java/com/joebrothers/chapter09/AbsIntegerEncoderTest.java

@@ -0,0 +1,34 @@
+package com.joebrothers.chapter09;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertNull;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+
+import org.junit.jupiter.api.Test;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.embedded.EmbeddedChannel;
+
+class AbsIntegerEncoderTest {
+
+    @Test
+    void testEncode() {
+        final ByteBuf buf = Unpooled.buffer();
+        for (int i = 1; i < 10; i++) {
+            buf.writeInt(i * -1);
+        }
+
+        final EmbeddedChannel channel = new EmbeddedChannel(new AbsIntegerEncoder());
+
+        // Write
+        assertTrue(channel.writeOutbound(buf));
+        assertTrue(channel.finish());
+
+        // Read
+        for (int i = 1; i < 10; i++) {
+            assertEquals(i, (int) channel.readOutbound());
+        }
+        assertNull(channel.readOutbound());
+    }
+}

chapter09-unit-testing/src/test/java/com/joebrothers/chapter09/FixedLengthFrameDecoderTest.java

@@ -0,0 +1,63 @@
+package com.joebrothers.chapter09;
+
+import static org.junit.jupiter.api.Assertions.*;
+
+import org.junit.jupiter.api.Test;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.embedded.EmbeddedChannel;
+
+class FixedLengthFrameDecoderTest {
+
+    @Test
+    public void testFramesDecoded() {
+        final ByteBuf buf = Unpooled.buffer();
+        for (int i = 0; i < 9; i++) {
+            buf.writeByte(i);
+        }
+
+        final ByteBuf input = buf.duplicate();
+        final EmbeddedChannel channel = new EmbeddedChannel(new FixedLengthFrameDecoder(3));
+
+        // Write bytes
+        assertTrue(channel.writeInbound(input.retain()));  // retain!
+        assertTrue(channel.finish());
+
+        // Read messages
+        ByteBuf read;
+        for (int i=0; i<3; i++) {
+            read = channel.readInbound();
+            assertEquals(buf.readSlice(3), read);
+            read.release();
+        }
+
+        assertNull(channel.readInbound());
+        buf.release();
+    }
+
+    @Test
+    public void testFramesDecoded2() {
+        final ByteBuf buf = Unpooled.buffer();
+        for (int i=0; i<9; i++) {
+            buf.writeByte(i);
+        }
+
+        final ByteBuf input = buf.duplicate();
+        final EmbeddedChannel channel = new EmbeddedChannel(new FixedLengthFrameDecoder(3));
+        assertFalse(channel.writeInbound(input.readBytes(2)));  // frame is not ready to be read!
+        assertTrue(channel.writeInbound(input.readBytes(7)));
+        assertTrue(channel.finish());
+
+        ByteBuf read;
+        for (int i=0; i<3; i++) {
+            read = channel.readInbound();
+            assertEquals(buf.readSlice(3), read);
+            read.release();
+        }
+
+        assertNull(channel.readInbound());
+        buf.release();
+    }
+
+}

chapter09-unit-testing/src/test/java/com/joebrothers/chapter09/FrameChunkDecoderTest.java

@@ -0,0 +1,53 @@
+package com.joebrothers.chapter09;
+
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertTrue;
+import static org.junit.jupiter.api.Assertions.fail;
+
+import org.junit.jupiter.api.Test;
+
+import io.netty.buffer.ByteBuf;
+import io.netty.buffer.Unpooled;
+import io.netty.channel.embedded.EmbeddedChannel;
+import io.netty.handler.codec.TooLongFrameException;
+
+class FrameChunkDecoderTest {
+
+    @Test
+    void testFramesDecoded() {
+        final ByteBuf buf = Unpooled.buffer();
+        for (int i = 0; i < 9; i++) {
+            buf.writeByte(i);
+        }
+        final ByteBuf input = buf.duplicate();
+
+        final EmbeddedChannel channel = new EmbeddedChannel(new FrameChunkDecoder(3));
+        assertTrue(channel.writeInbound(input.readBytes(2)));
+
+        try {
+            // bigger than max size
+            channel.writeInbound(input.readBytes(4));
+            fail();
+        } catch (TooLongFrameException e) {
+            // expected
+        }
+
+        assertTrue(channel.writeInbound(input.readBytes(3)));
+        assertTrue(channel.finish());
+
+        // Read
+        ByteBuf read;
+        {
+            read = channel.readInbound();
+            assertEquals(buf.readSlice(2), read);
+            read.release();
+        }
+        {
+            read = channel.readInbound();
+            assertEquals(buf.skipBytes(4).readSlice(3), read);
+            read.release();
+        }
+
+        buf.release();
+    }
+}

gradle/libs.versions.toml

@@ -5,12 +5,12 @@
 findbugs = "3.0.2"
 guava = "32.1.3-jre"
 javax-annotation = "1.3.2"
-junit-jupiter = "5.10.0"
+junit-bom = "5.10.0"
 netty-bom = "4.1.108.Final"
 
 [libraries]
 findbugs = { module = "com.google.code.findbugs:jsr305", version.ref = "findbugs" }
 guava = { module = "com.google.guava:guava", version.ref = "guava" }
 javax-annotation = { module = "javax.annotation:javax.annotation-api", version.ref = "javax-annotation" }
-junit-jupiter = { module = "org.junit.jupiter:junit-jupiter", version.ref = "junit-jupiter" }
+junit-bom = { module = "org.junit:junit-bom", version.ref = "junit-bom" }
 netty-bom = { module = "io.netty:netty-bom", version.ref = "netty-bom" }

settings.gradle.kts

@@ -13,5 +13,6 @@ plugins {
 rootProject.name = "netty-practice"
 include("core")
 include("chapter04-transport")
+include("chapter09-unit-testing")
 include("echo-client")
 include("echo-server")