Feat/1462/text search http api (#1471)

* Add assets text search endpoint

* Filter out assets from invalid transactions.

- Added the limit argument to limit the returned results
- Created and updated tests

* Added documentation for the assets endpoint.

- Added some docstrings

* Removed unnecessary fixtures

tests/web/test_assets.py

@@ -0,0 +1,83 @@
+import pytest
+
+ASSETS_ENDPOINT = '/api/v1/assets/'
+
+
+def test_get_assets_with_empty_text_search(client):
+    res = client.get(ASSETS_ENDPOINT + '?search=')
+    assert res.json == {'status': 400,
+                        'message': 'text_search cannot be empty'}
+    assert res.status_code == 400
+
+
+def test_get_assets_with_missing_text_search(client):
+    res = client.get(ASSETS_ENDPOINT)
+    assert res.status_code == 400
+
+
+@pytest.mark.genesis
+def test_get_assets(client, b):
+    from bigchaindb.models import Transaction
+    from bigchaindb.backend.mongodb.connection import MongoDBConnection
+
+    if isinstance(b.connection, MongoDBConnection):
+        # test returns empty list when no assets are found
+        res = client.get(ASSETS_ENDPOINT + '?search=abc')
+        assert res.json == []
+        assert res.status_code == 200
+
+        # create asset
+        asset = {'msg': 'abc'}
+        tx = Transaction.create([b.me], [([b.me], 1)],
+                                asset=asset).sign([b.me_private])
+        # create block
+        block = b.create_block([tx])
+        b.write_block(block)
+        # vote valid
+        vote = b.vote(block.id, b.get_last_voted_block().id, True)
+        b.write_vote(vote)
+
+        # test that asset is returned
+        res = client.get(ASSETS_ENDPOINT + '?search=abc')
+        assert res.status_code == 200
+        assert len(res.json) == 1
+        assert res.json[0] == {
+            'data': {'msg': 'abc'},
+            'id': tx.id
+        }
+    else:
+        # test that the correct error is returned if not running MongoDB
+        res = client.get(ASSETS_ENDPOINT + '?search=abc')
+        assert res.status_code == 400
+        assert res.json['message'].startswith('(OperationError)')
+
+
+@pytest.mark.genesis
+def test_get_assets_limit(client, b):
+    from bigchaindb.models import Transaction
+    from bigchaindb.backend.mongodb.connection import MongoDBConnection
+
+    if isinstance(b.connection, MongoDBConnection):
+        # create two assets
+        asset1 = {'msg': 'abc 1'}
+        asset2 = {'msg': 'abc 2'}
+        tx1 = Transaction.create([b.me], [([b.me], 1)],
+                                 asset=asset1).sign([b.me_private])
+        tx2 = Transaction.create([b.me], [([b.me], 1)],
+                                 asset=asset2).sign([b.me_private])
+        # create block
+        block = b.create_block([tx1, tx2])
+        b.write_block(block)
+        # vote valid
+        vote = b.vote(block.id, b.get_last_voted_block().id, True)
+        b.write_vote(vote)
+
+        # test that both assets are returned without limit
+        res = client.get(ASSETS_ENDPOINT + '?search=abc')
+        assert res.status_code == 200
+        assert len(res.json) == 2
+
+        # test that only one asset is returned when using limit=1
+        res = client.get(ASSETS_ENDPOINT + '?search=abc&limit=1')
+        assert res.status_code == 200
+        assert len(res.json) == 1