Add property-based tests and fix the bugs discovered.

Change-Id: I8deb1a7d75078c037714541d8f6f656052c2476c

2 files changed, 71 insertions, 9 deletions

diff --git a/jgvariant-ostree/src/test/java/eu/mulk/jgvariant/ostree/OstreeDecoderPropertyTest.java b/jgvariant-ostree/src/test/java/eu/mulk/jgvariant/ostree/OstreeDecoderPropertyTest.java
new file mode 100644
index 0000000..acd11c4
--- /dev/null
+++ b/jgvariant-ostree/src/test/java/eu/mulk/jgvariant/ostree/OstreeDecoderPropertyTest.java
@@ -0,0 +1,66 @@
+package eu.mulk.jgvariant.ostree;
+
+import eu.mulk.jgvariant.core.Decoder;
+import java.util.Map;
+import net.jqwik.api.*;
+
+@SuppressWarnings("java:S2187")
+class OstreeDecoderPropertyTest {
+
+  @Group
+  class SummaryRoundtripLaw implements RoundtripLaw<Summary> {
+
+    @Override
+    public Decoder<Summary> decoder() {
+      return Summary.decoder();
+    }
+
+    @Override
+    public Arbitrary<Summary> anyT() {
+      return anySummary();
+    }
+  }
+
+  interface RoundtripLaw<T> {
+
+    @Property
+    default boolean roundtripsWell(@ForAll(value = "anyT") T entityLeft) {
+      var decoder = decoder();
+      var bytes = decoder.encode(entityLeft);
+      var entityRight = decoder.decode(bytes);
+      return entityLeft.equals(entityRight);
+    }
+
+    Decoder<T> decoder();
+
+    @Provide
+    Arbitrary<T> anyT();
+  }
+
+  @Provide
+  Arbitrary<Summary> anySummary() {
+    return Combinators.combine(anySummaryEntry().list(), anyMetadata()).as(Summary::new);
+  }
+
+  @Provide
+  Arbitrary<Metadata> anyMetadata() {
+    return Arbitraries.of(new Metadata(Map.of()));
+  }
+
+  @Provide
+  Arbitrary<Summary.Entry> anySummaryEntry() {
+    return Combinators.combine(Arbitraries.strings(), anySummaryEntryValue())
+        .as(Summary.Entry::new);
+  }
+
+  @Provide
+  Arbitrary<Summary.Entry.Value> anySummaryEntryValue() {
+    return Combinators.combine(Arbitraries.integers(), anyChecksum(), anyMetadata())
+        .as(Summary.Entry.Value::new);
+  }
+
+  @Provide
+  Arbitrary<Checksum> anyChecksum() {
+    return Arbitraries.of(new Checksum(new ByteString(new byte[32])));
+  }
+}
diff --git a/jgvariant-ostree/src/test/java/eu/mulk/jgvariant/ostree/OstreeDecoderTest.java b/jgvariant-ostree/src/test/java/eu/mulk/jgvariant/ostree/OstreeDecoderTest.java
index 4465d02..793c5a5 100644
--- a/jgvariant-ostree/src/test/java/eu/mulk/jgvariant/ostree/OstreeDecoderTest.java
+++ b/jgvariant-ostree/src/test/java/eu/mulk/jgvariant/ostree/OstreeDecoderTest.java
@@ -110,10 +110,9 @@ class OstreeDecoderTest {
                 summary.metadata().fields()));
 
     var encoded = decoder.encode(summary);
+
     input.rewind();
     assertEquals(input, encoded);
-
-    System.out.println(summary);
   }
 
   @Test
@@ -123,10 +122,9 @@ class OstreeDecoderTest {
     var commit = decoder.decode(input);
 
     var encoded = decoder.encode(commit);
+
     input.rewind();
     assertEquals(input, encoded);
-
-    System.out.println(commit);
   }
 
   @Test
@@ -136,10 +134,9 @@ class OstreeDecoderTest {
     var dirTree = decoder.decode(input);
 
     var encoded = decoder.encode(dirTree);
+
     input.rewind();
     assertEquals(input, encoded);
-
-    System.out.println(dirTree);
   }
 
   @Test
@@ -149,10 +146,9 @@ class OstreeDecoderTest {
     var dirMeta = decoder.decode(ByteBuffer.wrap(dirMetaBytes));
 
     var encoded = decoder.encode(dirMeta);
+
     input.rewind();
     assertEquals(input, encoded);
-
-    System.out.println(dirMeta);
   }
 
   @Test
@@ -160,9 +156,9 @@ class OstreeDecoderTest {
     var decoder = DeltaSuperblock.decoder();
     var input = ByteBuffer.wrap(deltaSuperblockBytes);
     var deltaSuperblock = decoder.decode(input);
-    System.out.println(deltaSuperblock);
 
     var encoded = decoder.encode(deltaSuperblock);
+
     input.rewind();
     assertEquals(input, encoded);
   }