testing: Add functions to generate yaml filescoldtom/testing-api

Adds functions to the `buildstream.testing` package to allow plugins to
dump elements and projects on the fly. Before this plugins were just
accessing the private yaml API for tests and loading/dumping directly. I
also allow access to just `_yaml.load()` from testing.

2 files changed, 21 insertions, 0 deletions

diff --git a/src/buildstream/testing/__init__.py b/src/buildstream/testing/__init__.py
index 46cadbbfa..dafc3a9fe 100644
--- a/src/buildstream/testing/__init__.py
+++ b/src/buildstream/testing/__init__.py
@@ -22,6 +22,8 @@ This package contains various utilities which make it easier to test plugins.
 import os
 from collections import OrderedDict
 from buildstream.exceptions import ErrorDomain, LoadErrorReason
+from buildstream._yaml import load as load_yaml  # type: ignore
+from ._yaml import generate_project, generate_element
 from .repo import Repo
 from .runcli import cli, cli_integration, cli_remote_execution
 from .integration import integration_cache
diff --git a/src/buildstream/testing/_yaml.py b/src/buildstream/testing/_yaml.py
new file mode 100644
index 000000000..ccf65a1ae
--- /dev/null
+++ b/src/buildstream/testing/_yaml.py
@@ -0,0 +1,19 @@
+import os
+
+from buildstream._yaml import roundtrip_dump  # type: ignore
+
+
+def generate_project(project_dir, config=None):
+    if config is None:
+        config = {}
+    project_file = os.path.join(project_dir, "project.conf")
+    if "name" not in config:
+        config["name"] = os.path.basename(project_dir)
+    roundtrip_dump(config, project_file)
+
+
+def generate_element(element_dir, element_name, config=None):
+    if config is None:
+        config = {}
+    element_path = os.path.join(element_dir, element_name)
+    roundtrip_dump(config, element_path)