Implements JsonReader (#2)

tests/io/test_file.py

@@ -1,15 +1,11 @@
 import pytest
-from mock import MagicMock
 
 from bonobo import FileWriter, Bag, FileReader
 from bonobo.core.contexts import ComponentExecutionContext
+from bonobo.util.testing import CapturingComponentExecutionContext
 from bonobo.util.tokens import BEGIN, END
 
 
-class CapturingComponentExecutionContext(ComponentExecutionContext):
-    send = MagicMock()
-
-
 @pytest.mark.parametrize(
     'lines,output',
     [

tests/io/test_json.py

@@ -1,7 +1,8 @@
 import pytest
 
-from bonobo import Bag, JsonWriter
+from bonobo import Bag, JsonWriter, JsonReader
 from bonobo.core.contexts import ComponentExecutionContext
+from bonobo.util.testing import CapturingComponentExecutionContext
 from bonobo.util.tokens import BEGIN, END
 
 
@@ -33,3 +34,26 @@ def test_write_json_without_initializer_should_not_work(tmpdir):
     context = ComponentExecutionContext(json_writer, None)
     with pytest.raises(AttributeError):
         json_writer(context, {'foo': 'bar'})
+
+
+def test_read_json_from_file(tmpdir):
+    file = tmpdir.join('input.json')
+    file.write('[{"x": "foo"},{"x": "bar"}]')
+    reader = JsonReader(str(file))
+
+    context = CapturingComponentExecutionContext(reader, None)
+
+    context.initialize()
+    context.recv(BEGIN, Bag(), END)
+    context.step()
+    context.finalize()
+
+    assert len(context.send.mock_calls) == 2
+
+    args0, kwargs0 = context.send.call_args_list[0]
+    assert len(args0) == 1 and not len(kwargs0)
+    args1, kwargs1 = context.send.call_args_list[1]
+    assert len(args1) == 1 and not len(kwargs1)
+
+    assert args0[0].args[0] == {'x': 'foo'}
+    assert args1[0].args[0] == {'x': 'bar'}