Add property-based tests and fix the bugs discovered.
Change-Id: I8deb1a7d75078c037714541d8f6f656052c2476c
diff --git a/jgvariant-core/src/main/java/eu/mulk/jgvariant/core/Decoder.java b/jgvariant-core/src/main/java/eu/mulk/jgvariant/core/Decoder.java
index 9362487..fcbb639 100644
--- a/jgvariant-core/src/main/java/eu/mulk/jgvariant/core/Decoder.java
+++ b/jgvariant-core/src/main/java/eu/mulk/jgvariant/core/Decoder.java
@@ -342,14 +342,22 @@
}
private static int getIntN(ByteBuffer byteSlice) {
- var intBytes = new byte[4];
- byteSlice.get(intBytes, 0, Math.min(4, byteSlice.limit()));
- return ByteBuffer.wrap(intBytes).order(LITTLE_ENDIAN).getInt();
+ return switch (byteSlice.limit()) {
+ case 0 -> 0;
+ case 1 ->
+ Byte.toUnsignedInt(byteSlice.order(LITTLE_ENDIAN).get());
+ case 2 ->
+ Short.toUnsignedInt(byteSlice.order(LITTLE_ENDIAN).getShort());
+ case 4 ->
+ byteSlice.order(LITTLE_ENDIAN).getInt();
+ default ->
+ throw new IllegalArgumentException("invalid byte count: %d".formatted(byteSlice.limit()));
+ };
}
@SuppressWarnings("java:S3358")
private static int byteCount(int n) {
- return n < (1 << 8) ? 1 : n < (1 << 16) ? 2 : 4;
+ return n == 0 ? 0 : n < (1 << 8) ? 1 : n < (1 << 16) ? 2 : 4;
}
private static int computeFramingOffsetSize(int elementsRelativeEnd, List<Integer> framingOffsets) {
@@ -404,7 +412,7 @@
elements = List.of();
} else {
// An array with aligned elements and a vector of framing offsets in the end.
- int framingOffsetSize = byteCount(byteSlice.limit());
+ int framingOffsetSize = max(1, byteCount(byteSlice.limit()));
int lastFramingOffset =
getIntN(byteSlice.slice(byteSlice.limit() - framingOffsetSize, framingOffsetSize));
int elementCount = (byteSlice.limit() - lastFramingOffset) / framingOffsetSize;