manifest: accept strings as Manifest.from_data args

It's convenient when using this API to be able to pass a string
containing YAML data instead of requiring the caller to load the YAML
data every time.

Signed-off-by: Marti Bolivar <marti.bolivar@nordicsemi.no>

src/west/manifest.py

@@ -142,7 +142,8 @@ class Manifest:
     def from_data(source_data, manifest_path=None, topdir=None):
         '''Create and return a new Manifest object given parsed YAML data.
 
-        :param source_data: Parsed YAML data as a Python object.
+        :param source_data: Parsed YAML data as a Python object,
+                            or a string with YAML data inside.
         :param manifest_path: fallback ManifestProject path attribute
         :param topdir: If given, absolute paths in the result will be
                        rooted here.
@@ -163,6 +164,8 @@ class Manifest:
 
         Raises MalformedManifest in case of validation errors.
         '''
+        if isinstance(source_data, str):
+            source_data = yaml.safe_load(source_data)
         return Manifest(source_data=source_data, topdir=topdir,
                         manifest_path=manifest_path)
 

tests/test_manifest.py

@@ -757,6 +757,17 @@ def test_get_projects_unknown():
     with pytest.raises(ValueError):
         manifest.get_projects(['unknown'])
 
+def test_load_str():
+    # We can load manifest data as a string.
+
+    manifest = Manifest.from_data('''\
+    manifest:
+      projects:
+        - name: foo
+          url: https://foo.com
+    ''')
+    assert manifest.projects[-1].name == 'foo'
+
 
 # Invalid manifests should raise MalformedManifest.
 @pytest.mark.parametrize('invalid',