Support constructing applications calls with reject version. (#869)

Author: gmalouf

src/main/java/com/algorand/algosdk/builder/transaction/ApplicationBaseTransactionBuilder.java

@@ -49,6 +49,7 @@ public LocalsReference(Address address, long appId) {
     private List<HoldingReference> holdings;
     private List<LocalsReference> locals;
     private Long applicationId;
+    private Long rejectVersion;
     private boolean useAccess = false;
 
     /**
@@ -129,6 +130,7 @@ protected void applyTo(Transaction txn) {
         if (applicationId != null) txn.applicationId = applicationId;
         if (onCompletion != null) txn.onCompletion = onCompletion;
         if (applicationArgs != null) txn.applicationArgs = applicationArgs;
+        if (rejectVersion != null) txn.rejectVersion = rejectVersion;
     }
 
     @Override
@@ -224,28 +226,41 @@ public T locals(List<LocalsReference> locals) {
 
     /**
      * Enable or disable translation of foreign references into the access field.
-     * 
+     *
      * When useAccess=true:
      * - All foreign references (accounts, foreignApps, foreignAssets, boxReferences) are translated
      *   into a unified access field instead of using separate legacy fields
      * - You can still use the same methods (accounts(), foreignApps(), etc.) - they will be translated
      * - Advanced features (holdings(), locals()) are also available
      * - Compatible with networks that support the access field consensus upgrade
-     * 
+     *
      * When useAccess=false (default):
      * - Uses legacy separate fields (accounts, foreignApps, foreignAssets, boxReferences)
      * - No translation occurs - references are placed directly in their respective fields
      * - Maintains backward compatibility with pre-consensus upgrade networks
      * - Advanced features (holdings(), locals()) are not allowed
-     * 
+     *
      * This design allows easy migration - just add .useAccess(true) to enable access field mode
      * while keeping your existing foreign reference method calls.
-     * 
+     *
      * @param useAccess true to translate references to access field, false to use legacy fields
      * @return this builder instance
      */
     public T useAccess(boolean useAccess) {
         this.useAccess = useAccess;
         return (T) this;
     }
+
+    /**
+     * Set the reject version for the application call.
+     * The lowest application version for which this transaction should immediately fail.
+     * 0 indicates that no version check should be performed.
+     *
+     * @param rejectVersion the minimum application version to reject
+     * @return this builder instance
+     */
+    public T rejectVersion(Long rejectVersion) {
+        this.rejectVersion = rejectVersion;
+        return (T) this;
+    }
 }

src/main/java/com/algorand/algosdk/transaction/Transaction.java

@@ -165,6 +165,9 @@ public class Transaction implements Serializable {
     @JsonProperty("apep")
     public Long extraPages = 0L;
 
+    @JsonProperty("aprv")
+    public Long rejectVersion = 0L;
+
     /* access field - unifies accounts, foreignApps, foreignAssets, and boxReferences */
     @JsonProperty("al")
     public List<ResourceRef> access = new ArrayList<>();
@@ -246,6 +249,7 @@ private Transaction(@JsonProperty("type") Type type,
                         @JsonProperty("apls") StateSchema localStateSchema,
                         @JsonProperty("apsu") byte[] clearStateProgram,
                         @JsonProperty("apep") Long extraPages,
+                        @JsonProperty("aprv") Long rejectVersion,
                         // access fields
                         @JsonProperty("al") List<ResourceRef> access,
                         // heartbeat fields
@@ -301,6 +305,7 @@ private Transaction(@JsonProperty("type") Type type,
                 localStateSchema,
                 clearStateProgram == null ? null : new TEALProgram(clearStateProgram),
                 extraPages,
+                rejectVersion,
                 access == null ? new ArrayList<>() : access,
                 heartbeatFields
         );
@@ -362,6 +367,7 @@ private Transaction(
             StateSchema localStateSchema,
             TEALProgram clearStateProgram,
             Long extraPages,
+            Long rejectVersion,
             List<ResourceRef> access,
             HeartbeatTxnFields heartbeatFields
     ) {
@@ -408,6 +414,7 @@ private Transaction(
         if (localStateSchema != null) this.localStateSchema = localStateSchema;
         if (clearStateProgram != null) this.clearStateProgram = clearStateProgram;
         if (extraPages != null) this.extraPages = extraPages;
+        if (rejectVersion != null) this.rejectVersion = rejectVersion;
         if (access != null) this.access = access;
         if (heartbeatFields != null) this.heartbeatFields = heartbeatFields;
     }
@@ -622,6 +629,7 @@ public boolean equals(Object o) {
                 freezeState == that.freezeState &&
                 rekeyTo.equals(that.rekeyTo) &&
                 extraPages.equals(that.extraPages) &&
+                rejectVersion.equals(that.rejectVersion) &&
                 boxReferences.equals(that.boxReferences) &&
                 heartbeatFields.equals(that.heartbeatFields);
     }

src/test/java/com/algorand/algosdk/transaction/TestTransaction.java

@@ -1053,4 +1053,72 @@ public void TxnEstimatedDefaultFee() throws Exception {
         }
     }
 
+    @Test
+    public void testApplicationCallRejectVersion() throws Exception {
+        Address from = new Address("VKM6KSCTDHEM6KGEAMSYCNEGIPFJMHDSEMIRAQLK76CJDIRMMDHKAIRMFQ");
+        byte[] gh = Encoder.decodeFromBase64("SGO1GKSzyE7IEPItTxCByw9x8FmnrCDexi9/cOUJOiI=");
+
+        // Test with specific rejectVersion
+        Transaction txWithReject = Transaction.ApplicationCallTransactionBuilder()
+                .sender(from)
+                .applicationId(123L)
+                .firstValid(1000)
+                .lastValid(2000)
+                .genesisHash(gh)
+                .rejectVersion(5L)
+                .build();
+
+        // Verify rejectVersion is set
+        assertThat(txWithReject.rejectVersion).isEqualTo(5L);
+
+        // Test serialization/deserialization with msgpack
+        byte[] encodedTxn = Encoder.encodeToMsgPack(txWithReject);
+        Transaction decodedTxn = Encoder.decodeFromMsgPack(encodedTxn, Transaction.class);
+        assertThat(decodedTxn.rejectVersion).isEqualTo(5L);
+        assertEqual(txWithReject, decodedTxn);
+
+        // Test serialization/deserialization with JSON
+        ObjectMapper objectMapper = new ObjectMapper();
+        String transactionJson = objectMapper.writeValueAsString(txWithReject);
+        Transaction jsonDecodedTxn = objectMapper.readValue(transactionJson, Transaction.class);
+        assertThat(jsonDecodedTxn.rejectVersion).isEqualTo(5L);
+        assertEqual(txWithReject, jsonDecodedTxn);
+
+        // Verify aprv field is present in JSON when rejectVersion is non-zero
+        assertThat(transactionJson).contains("\"aprv\":5");
+
+        // Test with default rejectVersion (should be 0)
+        Transaction txDefault = Transaction.ApplicationCallTransactionBuilder()
+                .sender(from)
+                .applicationId(456L)
+                .firstValid(1000)
+                .lastValid(2000)
+                .genesisHash(gh)
+                .build();
+
+        // Verify default rejectVersion is 0
+        assertThat(txDefault.rejectVersion).isEqualTo(0L);
+
+        // Verify aprv field is NOT present in JSON when rejectVersion is 0 (default omission)
+        String txDefaultJson = objectMapper.writeValueAsString(txDefault);
+        assertThat(txDefaultJson).doesNotContain("aprv");
+
+        // Test explicit 0 rejectVersion
+        Transaction txExplicitZero = Transaction.ApplicationCallTransactionBuilder()
+                .sender(from)
+                .applicationId(456L)
+                .firstValid(1000)
+                .lastValid(2000)
+                .genesisHash(gh)
+                .rejectVersion(0L)
+                .build();
+
+        assertThat(txExplicitZero.rejectVersion).isEqualTo(0L);
+        assertEqual(txDefault, txExplicitZero);
+
+        // Verify aprv field is NOT present in JSON when rejectVersion is explicitly 0
+        String txExplicitZeroJson = objectMapper.writeValueAsString(txExplicitZero);
+        assertThat(txExplicitZeroJson).doesNotContain("aprv");
+    }
+
 }