1 files changed, 437 insertions, 0 deletions
diff --git a/jgvariant-core/src/test/java/eu/mulk/jgvariant/core/DecoderTest.java b/jgvariant-core/src/test/java/eu/mulk/jgvariant/core/DecoderTest.java
new file mode 100644
index 0000000..5cf1a1c
--- /dev/null
+++ b/jgvariant-core/src/test/java/eu/mulk/jgvariant/core/DecoderTest.java
@@ -0,0 +1,437 @@
+package eu.mulk.jgvariant.core;
+
+import static java.nio.ByteOrder.BIG_ENDIAN;
+import static java.nio.ByteOrder.LITTLE_ENDIAN;
+import static java.nio.charset.StandardCharsets.UTF_8;
+import static org.junit.jupiter.api.Assertions.assertAll;
+import static org.junit.jupiter.api.Assertions.assertArrayEquals;
+import static org.junit.jupiter.api.Assertions.assertEquals;
+import static org.junit.jupiter.api.Assertions.assertThrows;
+
+import java.nio.ByteBuffer;
+import java.text.ParseException;
+import java.util.List;
+import java.util.Optional;
+import org.junit.jupiter.api.Test;
+
+/**
+ * Tests based on the examples given in <a
+ * href="https://people.gnome.org/~desrt/gvariant-serialisation.pdf">~desrt/gvariant-serialisation.pdf</a>.
+ */
+class DecoderTest {
+
+  @Test
+  void testString() {
+    var data = new byte[] {0x68, 0x65, 0x6C, 0x6C, 0x6F, 0x20, 0x77, 0x6F, 0x72, 0x6C, 0x64, 0x00};
+    var decoder = Decoder.ofString(UTF_8);
+    assertEquals("hello world", decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testMaybe() {
+    var data =
+        new byte[] {0x68, 0x65, 0x6C, 0x6C, 0x6F, 0x20, 0x77, 0x6F, 0x72, 0x6C, 0x64, 0x00, 0x00};
+    var decoder = Decoder.ofMaybe(Decoder.ofString(UTF_8));
+    assertEquals(Optional.of("hello world"), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testBooleanArray() {
+    var data = new byte[] {0x01, 0x00, 0x00, 0x01, 0x01};
+    var decoder = Decoder.ofArray(Decoder.ofBoolean());
+    assertEquals(List.of(true, false, false, true, true), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testStructure() {
+    var data =
+        new byte[] {
+          0x66, 0x6F, 0x6F, 0x00, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, 0x04
+        };
+
+    record TestRecord(String s, int i) {}
+
+    var decoder = Decoder.ofStructure(TestRecord.class, Decoder.ofString(UTF_8), Decoder.ofInt());
+    assertEquals(new TestRecord("foo", -1), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testComplexStructureArray() {
+    var data =
+        new byte[] {
+          0x68,
+          0x69,
+          0x00,
+          0x00,
+          (byte) 0xfe,
+          (byte) 0xff,
+          (byte) 0xff,
+          (byte) 0xff,
+          0x03,
+          0x00,
+          0x00,
+          0x00,
+          0x62,
+          0x79,
+          0x65,
+          0x00,
+          (byte) 0xff,
+          (byte) 0xff,
+          (byte) 0xff,
+          (byte) 0xff,
+          0x04,
+          0x09,
+          0x15
+        };
+
+    record TestRecord(String s, int i) {}
+
+    var decoder =
+        Decoder.ofArray(
+            Decoder.ofStructure(
+                TestRecord.class,
+                Decoder.ofString(UTF_8),
+                Decoder.ofInt().withByteOrder(LITTLE_ENDIAN)));
+    assertEquals(
+        List.of(new TestRecord("hi", -2), new TestRecord("bye", -1)),
+        decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testStringArray() {
+    var data =
+        new byte[] {
+          0x69, 0x00, 0x63, 0x61, 0x6E, 0x00, 0x68, 0x61, 0x73, 0x00, 0x73, 0x74, 0x72, 0x69, 0x6E,
+          0x67, 0x73, 0x3F, 0x00, 0x02, 0x06, 0x0a, 0x13
+        };
+    var decoder = Decoder.ofArray(Decoder.ofString(UTF_8));
+    assertEquals(List.of("i", "can", "has", "strings?"), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testNestedStructure() {
+    var data =
+        new byte[] {
+          0x69, 0x63, 0x61, 0x6E, 0x00, 0x68, 0x61, 0x73, 0x00, 0x73, 0x74, 0x72, 0x69, 0x6E, 0x67,
+          0x73, 0x3F, 0x00, 0x04, 0x0d, 0x05
+        };
+
+    record TestChild(byte b, String s) {}
+    record TestParent(TestChild tc, List<String> as) {}
+
+    var decoder =
+        Decoder.ofStructure(
+            TestParent.class,
+            Decoder.ofStructure(TestChild.class, Decoder.ofByte(), Decoder.ofString(UTF_8)),
+            Decoder.ofArray(Decoder.ofString(UTF_8)));
+
+    assertEquals(
+        new TestParent(new TestChild((byte) 0x69, "can"), List.of("has", "strings?")),
+        decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testNestedStructureVariant() {
+    var data =
+        new byte[] {
+          0x69, 0x63, 0x61, 0x6E, 0x00, 0x68, 0x61, 0x73, 0x00, 0x73, 0x74, 0x72, 0x69, 0x6E, 0x67,
+          0x73, 0x3F, 0x00, 0x04, 0x0d, 0x05, 0x00, 0x28, 0x28, 0x79, 0x73, 0x29, 0x61, 0x73, 0x29
+        };
+
+    var decoder = Decoder.ofVariant();
+    var variant = decoder.decode(ByteBuffer.wrap(data));
+    var result = (Object[]) variant.value();
+
+    assertAll(
+        () -> assertEquals(Signature.parse("((ys)as)"), variant.signature()),
+        () -> assertEquals(2, result.length),
+        () -> assertArrayEquals(new Object[] {(byte) 0x69, "can"}, (Object[]) result[0]),
+        () -> assertEquals(List.of("has", "strings?"), result[1]));
+  }
+
+  @Test
+  void testSimpleStructure() {
+    var data = new byte[] {0x60, 0x70};
+
+    record TestRecord(byte b1, byte b2) {}
+
+    var decoder =
+        Decoder.ofStructure(
+            TestRecord.class,
+            Decoder.ofByte().withByteOrder(LITTLE_ENDIAN),
+            Decoder.ofByte().withByteOrder(LITTLE_ENDIAN));
+
+    assertEquals(new TestRecord((byte) 0x60, (byte) 0x70), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testPaddedStructureRight() {
+    var data = new byte[] {0x60, 0x00, 0x00, 0x00, 0x70, 0x00, 0x00, 0x00};
+
+    record TestRecord(int b1, byte b2) {}
+
+    var decoder =
+        Decoder.ofStructure(
+            TestRecord.class,
+            Decoder.ofInt().withByteOrder(LITTLE_ENDIAN),
+            Decoder.ofByte().withByteOrder(LITTLE_ENDIAN));
+
+    assertEquals(new TestRecord(0x60, (byte) 0x70), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testPaddedStructureLeft() {
+    var data = new byte[] {0x60, 0x00, 0x00, 0x00, 0x70, 0x00, 0x00, 0x00};
+
+    record TestRecord(byte b1, int b2) {}
+
+    var decoder =
+        Decoder.ofStructure(
+            TestRecord.class,
+            Decoder.ofByte().withByteOrder(LITTLE_ENDIAN),
+            Decoder.ofInt().withByteOrder(LITTLE_ENDIAN));
+
+    assertEquals(new TestRecord((byte) 0x60, 0x70), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testSimpleStructureArray() {
+    var data =
+        new byte[] {
+          0x60,
+          0x00,
+          0x00,
+          0x00,
+          0x70,
+          0x00,
+          0x00,
+          0x00,
+          (byte) 0x88,
+          0x02,
+          0x00,
+          0x00,
+          (byte) 0xF7,
+          0x00,
+          0x00,
+          0x00
+        };
+
+    record TestRecord(int b1, byte b2) {}
+
+    var decoder =
+        Decoder.ofArray(
+            Decoder.ofStructure(
+                TestRecord.class,
+                Decoder.ofInt().withByteOrder(LITTLE_ENDIAN),
+                Decoder.ofByte().withByteOrder(LITTLE_ENDIAN)));
+
+    assertEquals(
+        List.of(new TestRecord(96, (byte) 0x70), new TestRecord(648, (byte) 0xf7)),
+        decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testByteArray() {
+    var data = new byte[] {0x04, 0x05, 0x06, 0x07};
+
+    var decoder = Decoder.ofArray(Decoder.ofByte());
+
+    assertEquals(
+        List.of((byte) 0x04, (byte) 0x05, (byte) 0x06, (byte) 0x07),
+        decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testIntegerArray() {
+    var data = new byte[] {0x04, 0x00, 0x00, 0x00, 0x02, 0x01, 0x00, 0x00};
+
+    var decoder = Decoder.ofArray(Decoder.ofInt().withByteOrder(LITTLE_ENDIAN));
+
+    assertEquals(List.of(4, 258), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testDictionaryEntry() {
+    var data =
+        new byte[] {0x61, 0x20, 0x6B, 0x65, 0x79, 0x00, 0x00, 0x00, 0x02, 0x02, 0x00, 0x00, 0x06};
+
+    record TestEntry(String key, int value) {}
+
+    var decoder =
+        Decoder.ofStructure(
+            TestEntry.class, Decoder.ofString(UTF_8), Decoder.ofInt().withByteOrder(LITTLE_ENDIAN));
+    assertEquals(new TestEntry("a key", 514), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testPaddedPrimitives() {
+    var data =
+        new byte[] {
+          0x00, 0x01, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x02, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00,
+          0x00, 0x40, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00
+        };
+
+    record TestRecord(short s, long l, double d) {}
+
+    var decoder =
+        Decoder.ofStructure(
+            TestRecord.class,
+            Decoder.ofShort().withByteOrder(BIG_ENDIAN),
+            Decoder.ofLong().withByteOrder(LITTLE_ENDIAN),
+            Decoder.ofDouble());
+    assertEquals(new TestRecord((short) 1, 2, 3.25), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testEmbeddedMaybe() {
+    var data = new byte[] {0x01, 0x01};
+
+    record TestRecord(Optional<Byte> set, Optional<Byte> unset) {}
+
+    var decoder =
+        Decoder.ofStructure(
+            TestRecord.class, Decoder.ofMaybe(Decoder.ofByte()), Decoder.ofMaybe(Decoder.ofByte()));
+    assertEquals(
+        new TestRecord(Optional.of((byte) 1), Optional.empty()),
+        decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testRecordComponentMismatch() {
+    record TestRecord(Optional<Byte> set) {}
+
+    var maybeDecoder = Decoder.ofMaybe(Decoder.ofByte());
+    assertThrows(
+        IllegalArgumentException.class,
+        () -> Decoder.ofStructure(TestRecord.class, maybeDecoder, maybeDecoder));
+  }
+
+  @Test
+  void testTrivialRecord() {
+    var data = new byte[] {0x00};
+
+    record TestRecord() {}
+
+    var decoder = Decoder.ofStructure(TestRecord.class);
+    assertEquals(new TestRecord(), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testTwoElementTrivialRecordArray() {
+    var data = new byte[] {0x00, 0x00};
+
+    record TestRecord() {}
+
+    var decoder = Decoder.ofArray(Decoder.ofStructure(TestRecord.class));
+    assertEquals(
+        List.of(new TestRecord(), new TestRecord()), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testSingletonTrivialRecordArray() {
+    var data = new byte[] {0x00};
+
+    record TestRecord() {}
+
+    var decoder = Decoder.ofArray(Decoder.ofStructure(TestRecord.class));
+    assertEquals(List.of(new TestRecord()), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testEmptyTrivialRecordArray() {
+    var data = new byte[] {};
+
+    record TestRecord() {}
+
+    var decoder = Decoder.ofArray(Decoder.ofStructure(TestRecord.class));
+    assertEquals(List.of(), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testVariantArray() {
+    var data = new byte[] {};
+
+    record TestRecord() {}
+
+    var decoder = Decoder.ofArray(Decoder.ofStructure(TestRecord.class));
+    assertEquals(List.of(), decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testInvalidVariantSignature() {
+    var data = new byte[] {0x00, 0x00, 0x2E};
+
+    var decoder = Decoder.ofVariant();
+    assertThrows(IllegalArgumentException.class, () -> decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testMissingVariantSignature() {
+    var data = new byte[] {0x01};
+
+    var decoder = Decoder.ofVariant();
+    assertThrows(IllegalArgumentException.class, () -> decoder.decode(ByteBuffer.wrap(data)));
+  }
+
+  @Test
+  void testSimpleVariantRecord() throws ParseException {
+    // signature: "(bynqiuxtdsogvmiai)"
+    var data =
+        new byte[] {
+          0x01, // b
+          0x02, // y
+          0x00, 0x03, // n
+          0x00, 0x04, // q
+          0x00, 0x00, // (padding)
+          0x00, 0x00, 0x00, 0x05, // i
+          0x00, 0x00, 0x00, 0x06, // u
+          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x07, // x
+          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x08, // t
+          0x40, 0x0a, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // d
+          0x68, 0x69, 0x00, // s
+          0x68, 0x69, 0x00, // o
+          0x68, 0x69, 0x00, // g
+          0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, // (padding)
+          0x00, 0x00, 0x00, 0x09, 0x00, 0x69, // v
+          0x00, 0x00, // (padding)
+          0x00, 0x00, 0x00, 0x0a, // mi
+          0x00, 0x00, 0x00, 0x0b, 0x00, 0x00, 0x00, 0x0c, // ai
+          68, 62, 49, 46, 43, // framing offsets
+          0x00, 0x28, 0x62, 0x79, 0x6E, 0x71, 0x69, 0x75, 0x78, 0x74, 0x64, 0x73, 0x6F, 0x67, 0x76,
+          0x6D, 0x69, 0x61, 0x69, 0x29
+        };
+
+    var decoder = Decoder.ofVariant();
+    assertArrayEquals(
+        new Object[] {
+          true,
+          (byte) 2,
+          (short) 3,
+          (short) 4,
+          (int) 5,
+          (int) 6,
+          (long) 7,
+          (long) 8,
+          (double) 3.25,
+          "hi",
+          "hi",
+          "hi",
+          new Variant(Signature.parse("i"), 9),
+          Optional.of(10),
+          List.of(11, 12)
+        },
+        (Object[]) decoder.decode(ByteBuffer.wrap(data)).value());
+  }
+
+  @Test
+  void testSignatureString() throws ParseException {
+    var data =
+        new byte[] {
+          0x28, 0x62, 0x79, 0x6E, 0x71, 0x69, 0x75, 0x78, 0x74, 0x64, 0x73, 0x6F, 0x67, 0x76, 0x6D,
+          0x69, 0x61, 0x69, 0x29
+        };
+
+    var signature = Signature.parse(ByteBuffer.wrap(data));
+    assertEquals("(bynqiuxtdsogvmiai)", signature.toString());
+  }
+}