/transactions/ID only returns VALID transactions

bigchaindb/web/views/transactions.py

@@ -28,9 +28,9 @@ class TransactionApi(Resource):
         pool = current_app.config['bigchain_pool']
 
         with pool() as bigchain:
-            tx = bigchain.get_transaction(tx_id)
+            tx, status = bigchain.get_transaction(tx_id, include_status=True)
 
-        if not tx:
+        if not tx or status is not bigchain.TX_VALID:
             return make_error(404)
 
         return tx.to_dict()

docs/server/source/http-client-server-api.rst

@@ -46,12 +46,12 @@ Transactions
 
    Get the transaction with the ID ``tx_id``.
 
-   This endpoint returns a transaction if it was included in a ``VALID`` block,
-   if it is still waiting to be processed (``BACKLOG``) or is still in an
-   undecided block (``UNDECIDED``). All instances of a transaction in invalid
-   blocks are ignored and treated as if they don't exist. If a request is made
-   for a transaction and instances of that transaction are found only in
-   invalid blocks, then the response will be ``404 Not Found``.
+   This endpoint returns a transaction if it was included in a ``VALID`` block.
+   All instances of a transaction in invalid/undecided blocks or the backlog
+   are ignored and treated as if they don't exist. If a request is made for a
+   transaction and instances of that transaction are found only in
+   invalid/undecided blocks or the backlog, then the response will be ``404 Not
+   Found``.
 
    :param tx_id: transaction ID
    :type tx_id: hex string

tests/web/test_transactions.py

@@ -270,3 +270,26 @@ def test_transactions_get_list_bad(client):
         # Test asset ID required
         url = TX_ENDPOINT + '?operation=CREATE'
         assert client.get(url).status_code == 400
+
+
+def test_return_only_valid_transaction(client):
+    from bigchaindb import Bigchain
+
+    def get_transaction_patched(status):
+        def inner(self, tx_id, include_status):
+            return {}, status
+        return inner
+
+    # NOTE: `get_transaction` only returns a transaction if it's included in an
+    #       UNDECIDED or VALID block, as well as transactions from the backlog.
+    #       As the endpoint uses `get_transaction`, we don't have to test
+    #       against invalid transactions here.
+    with patch('bigchaindb.core.Bigchain.get_transaction',
+               get_transaction_patched(Bigchain.TX_UNDECIDED)):
+        url = '{}{}'.format(TX_ENDPOINT, '123')
+        assert client.get(url).status_code == 404
+
+    with patch('bigchaindb.core.Bigchain.get_transaction',
+               get_transaction_patched(Bigchain.TX_IN_BACKLOG)):
+        url = '{}{}'.format(TX_ENDPOINT, '123')
+        assert client.get(url).status_code == 404