Added support for default heredocs value when creating a Command in Python, to avoid breaking current Command API.

Author: sebastian-echeverria

pylib/support.c

@@ -69,10 +69,18 @@ static PyObject* _setup_module(PyObject* module) {
 
         PyObject* collections = PyImport_ImportModule("collections");
 
-        PyDockerfile_Command = PyObject_CallMethod(
-            collections, "namedtuple", "ss",
-            "Command", "cmd sub_cmd json original start_line end_line flags value heredocs"
-        );
+        // Set up a Command namedtuple object, with empty default for heredocs substructure.
+        PyObject* defaults = PyTuple_New(1);
+        PyObject* default_heredoc = PyTuple_New(0);
+        PyTuple_SetItem(defaults, 0, default_heredoc);
+        PyObject *args = Py_BuildValue("ss", "Command",  "cmd sub_cmd json original start_line end_line flags value heredocs");
+        PyObject *keywords = PyDict_New();
+        PyDict_SetItemString(keywords, "defaults", defaults);
+        PyObject *namedtuple_method = PyObject_GetAttrString(collections, "namedtuple");
+        PyDockerfile_Command = PyObject_Call(namedtuple_method, args, keywords);
+        Py_DECREF(args);
+        Py_DECREF(keywords);
+        Py_DECREF(namedtuple_method);
         PyObject_SetAttrString(
             PyDockerfile_Command, "__module__",
             PyObject_GetAttrString(module, "__name__")

tests/dockerfile_test.py

@@ -42,37 +42,31 @@ def test_parse_string_success():
             cmd='FROM', sub_cmd=None, json=False, flags=(),
             value=('ubuntu:xenial',),
             start_line=1, end_line=1, original='FROM ubuntu:xenial',
-            heredocs=(),
         ),
         dockerfile.Command(
             cmd='RUN', sub_cmd=None, json=False, flags=(),
             value=('echo hi > /etc/hi.conf',),
             start_line=2, end_line=2, original='RUN echo hi > /etc/hi.conf',
-            heredocs=(),
         ),
         dockerfile.Command(
             cmd='CMD', sub_cmd=None, json=True, flags=(), value=('echo',),
             start_line=3, end_line=3, original='CMD ["echo"]',
-            heredocs=(),
         ),
         dockerfile.Command(
             cmd='HEALTHCHECK', sub_cmd=None, json=False,
             flags=('--retries=5',), value=('CMD', 'echo hi'),
             start_line=4, end_line=4,
             original='HEALTHCHECK --retries=5 CMD echo hi',
-            heredocs=(),
         ),
         dockerfile.Command(
             cmd='ONBUILD', sub_cmd='ADD', json=False, flags=(),
             value=('foo', 'bar'),
             start_line=5, end_line=5, original='ONBUILD ADD foo bar',
-            heredocs=(),
         ),
         dockerfile.Command(
             cmd='ONBUILD', sub_cmd='RUN', json=True, flags=(),
             value=('cat', 'bar'),
             start_line=6, end_line=6, original='ONBUILD RUN ["cat", "bar"]',
-            heredocs=(),
         ),
     )
 
@@ -86,12 +80,10 @@ def test_parse_string_text():
         dockerfile.Command(
             cmd='FROM', sub_cmd=None, json=False, value=('ubuntu:xenial',),
             start_line=1, end_line=1, original='FROM ubuntu:xenial', flags=(),
-            heredocs=(),
         ),
         dockerfile.Command(
             cmd='CMD', sub_cmd=None, json=True, value=('echo', '☃'),
             start_line=2, end_line=2, original='CMD ["echo", "☃"]', flags=(),
-            heredocs=(),
         ),
     )
 
@@ -103,12 +95,10 @@ def test_parse_file_success():
             cmd='FROM', sub_cmd=None, json=False, flags=(),
             value=('ubuntu:xenial',),
             start_line=1, end_line=1, original='FROM ubuntu:xenial',
-            heredocs=(),
         ),
         dockerfile.Command(
             cmd='CMD', sub_cmd=None, json=True, flags=(), value=('echo', 'hi'),
             start_line=2, end_line=2, original='CMD ["echo", "hi"]',
-            heredocs=(),
         ),
     )