fix bitfield off-by-one encoding

Author: yuzawa-san

iabgpp-encoder/src/main/java/com/iab/gpp/encoder/datatype/encoder/FixedBitfieldEncoder.java

@@ -8,7 +8,7 @@ private FixedBitfieldEncoder() {}
 
   public static void encode(BitString builder, IntegerSet value, int bitStringLength) {
     for (int i = 0; i < bitStringLength; i++) {
-      builder.writeBoolean(value.containsInt(i));
+      builder.writeBoolean(value.containsInt(i + 1));
     }
   }
 }

iabgpp-encoder/src/test/java/com/iab/gpp/encoder/GppModelTest.java

@@ -397,7 +397,7 @@ public void testEncodeUspV1AndTcfEuV2AndTcfCaV1() {
 
     String gppString = gppModel.encode();
     Assertions.assertEquals(
-        "DBACOeA~CPSG_8APSG_8ANwAAAENAwCAAAAAAAAAAAAAAAAAAAAA.IAAA~BPSG_8APSG_8AAyACAENGdCgf_gfgAfgfgBgABABAAABAB4AACACAAA.fHHHA4444ao~1YNN",
+        "DBACOeA~CPSG_8APSG_8ANwAAAENAwCAAAAAAAAAAAAAAAAAAAAA.IAAA~BPSG_8APSG_8AAyACAENGdCg_fA_AA_A_ABgABABAAABAB4AACACAAA.eOOOBxxxwcQ~1YNN",
         gppString);
 
     Assertions.assertEquals(4, gppString.split("~").length);
@@ -824,12 +824,10 @@ public void testDecode9() {
   public void testConsistency() {
     GppModel fromObjectModel = new GppModel();
 
-    fromObjectModel.setFieldValue(
-        TcfEuV2.NAME, TcfEuV2Field.PURPOSE_CONSENTS, Arrays.asList(0, 1, 2, 3, 4, 5, 6, 7, 8, 9));
-    fromObjectModel.setFieldValue(
-        TcfEuV2.NAME,
-        TcfEuV2Field.VENDOR_CONSENTS,
-        Arrays.asList(32, 128, 81, 210, 755, 21, 173, 238));
+    Set<Integer> purposeConsents = Set.of(1, 2, 4, 5, 6, 8, 9);
+    fromObjectModel.setFieldValue(TcfEuV2.NAME, TcfEuV2Field.PURPOSE_CONSENTS, purposeConsents);
+    Set<Integer> vendorConsents = Set.of(32, 128, 81, 210, 755, 21, 173, 238);
+    fromObjectModel.setFieldValue(TcfEuV2.NAME, TcfEuV2Field.VENDOR_CONSENTS, vendorConsents);
 
     Assertions.assertEquals(
         fromObjectModel.getSection(TcfEuV2.NAME).encode(),
@@ -839,11 +837,9 @@ public void testConsistency() {
     GppModel decodedModel = new GppModel(fromObjectModel.encode());
 
     Assertions.assertEquals(
-        Set.of(1, 2, 3, 4, 5, 6, 7, 8, 9, 10),
-        decodedModel.getFieldValue(TcfEuV2.NAME, TcfEuV2Field.PURPOSE_CONSENTS));
+        purposeConsents, decodedModel.getFieldValue(TcfEuV2.NAME, TcfEuV2Field.PURPOSE_CONSENTS));
     Assertions.assertEquals(
-        Set.of(21, 32, 81, 128, 173, 210, 238, 755),
-        decodedModel.getFieldValue(TcfEuV2.NAME, TcfEuV2Field.VENDOR_CONSENTS));
+        vendorConsents, decodedModel.getFieldValue(TcfEuV2.NAME, TcfEuV2Field.VENDOR_CONSENTS));
   }
 
   @Test

iabgpp-encoder/src/test/java/com/iab/gpp/encoder/datatype/encoder/FixedBitfieldEncoderTest.java

@@ -13,8 +13,13 @@ public class FixedBitfieldEncoderTest {
   public void testEncode1() {
     BitString builder = new BitString();
     IntegerSet set = new IntegerSet();
-    FixedBitfieldEncoder.encode(builder, set, 2);
-    Assertions.assertEquals("00", builder.toString());
+    set.add(2);
+    set.add(4);
+    set.add(6);
+    FixedBitfieldEncoder.encode(builder, set, 6);
+    String encoded = builder.toString();
+    Assertions.assertEquals("010101", encoded);
+    Assertions.assertEquals(set, decode(encoded));
   }
 
   @Test
@@ -29,7 +34,7 @@ public void testEncode2() {
   public void testEncode3() {
     BitString builder = new BitString();
     IntegerSet set = new IntegerSet();
-    set.add(0);
+    set.add(1);
     FixedBitfieldEncoder.encode(builder, set, 1);
     Assertions.assertEquals("1", builder.toString());
   }
@@ -48,24 +53,24 @@ public void testEncode5() {
     IntegerSet set = new IntegerSet();
     set.addInt(1);
     FixedBitfieldEncoder.encode(builder, set, 2);
-    Assertions.assertEquals("01", builder.toString());
+    Assertions.assertEquals("10", builder.toString());
   }
 
   @Test
   public void testEncode6() {
     BitString builder = new BitString();
     IntegerSet set = new IntegerSet();
-    set.addInt(0);
+    set.addInt(2);
     FixedBitfieldEncoder.encode(builder, set, 2);
-    Assertions.assertEquals("10", builder.toString());
+    Assertions.assertEquals("01", builder.toString());
   }
 
   @Test
   public void testEncode7() {
     BitString builder = new BitString();
     IntegerSet set = new IntegerSet();
-    set.addInt(0);
     set.addInt(1);
+    set.addInt(2);
     FixedBitfieldEncoder.encode(builder, set, 2);
     Assertions.assertEquals("11", builder.toString());
   }

iabgpp-encoder/src/test/java/com/iab/gpp/encoder/section/TcfCaV1Test.java

@@ -66,7 +66,7 @@ public void testEncode2() {
         ZonedDateTime.of(2022, 1, 1, 0, 0, 0, 0, ZoneId.of("UTC")).toInstant());
 
     Assertions.assertEquals(
-        "BPSG_8APSG_8AAyACAENGdCgf_gfgAfgfgBgABABAAABAB4AACACAAA.fHHHA4444ao", tcfCaV1.encode());
+        "BPSG_8APSG_8AAyACAENGdCg_fA_AA_A_ABgABABAAABAB4AACACAAA.eOOOBxxxwcQ", tcfCaV1.encode());
   }
 
   @Test