_yaml: Add 'as_str()' on ScalarNode and 'get_scalar()' on MappingNode

- 'get_scalar()' allows retrieving a scalar node from a mapping.
- 'as_str()' casts a ScalarNode into a string (thus removing the node
  information).

Both together, those replace 'node_get(mapping, key, type=str)' but
also allow retrieving the 'Node' itself, which will allow in the future
lazier provenance computation.

2 files changed, 6 insertions, 6 deletions

diff --git a/tests/sources/git.py b/tests/sources/git.py
index 45a2b827a..2b8a12997 100644
--- a/tests/sources/git.py
+++ b/tests/sources/git.py
@@ -760,7 +760,7 @@ def test_track_fetch(cli, tmpdir, datafiles, ref_format, tag, extra_commit):
     result.assert_success()
 
     element = _yaml.load(element_path)
-    new_ref = _yaml.node_get(_yaml.node_get(element, dict, 'sources', [0]), str, 'ref')
+    new_ref = _yaml.node_get(element, dict, 'sources', [0]).get_str('ref')
 
     if ref_format == 'git-describe' and tag:
         # Check and strip prefix
@@ -857,8 +857,8 @@ def test_git_describe(cli, tmpdir, datafiles, ref_storage, tag_type):
             assert 'annotated' in tag
             assert _yaml.node_get(tag, bool, 'annotated') == (tag_type == 'annotated')
 
-        assert {(_yaml.node_get(tag, str, 'tag'),
-                 _yaml.node_get(tag, str, 'commit'))
+        assert {(tag.get_str('tag'),
+                 tag.get_str('commit'))
                 for tag in tags} == {('tag1', repo.rev_parse('tag1^{commit}')),
                                      ('tag2', repo.rev_parse('tag2^{commit}'))}
 
@@ -972,8 +972,8 @@ def test_git_describe_head_is_tagged(cli, tmpdir, datafiles, ref_storage, tag_ty
         assert 'annotated' in tag
         assert _yaml.node_get(tag, bool, 'annotated') == (tag_type == 'annotated')
 
-        tag_name = _yaml.node_get(tag, str, 'tag')
-        commit = _yaml.node_get(tag, str, 'commit')
+        tag_name = tag.get_str('tag')
+        commit = tag.get_str('commit')
         assert (tag_name, commit) == ('tag', repo.rev_parse('tag^{commit}'))
 
     checkout = os.path.join(str(tmpdir), 'checkout')
diff --git a/tests/sources/previous_source_access/plugins/sources/foo_transform.py b/tests/sources/previous_source_access/plugins/sources/foo_transform.py
index bec4f9913..cd0f621d5 100644
--- a/tests/sources/previous_source_access/plugins/sources/foo_transform.py
+++ b/tests/sources/previous_source_access/plugins/sources/foo_transform.py
@@ -32,7 +32,7 @@ class FooTransformSource(Source):
 
     def configure(self, node):
         self.node_validate(node, ['ref', *Source.COMMON_CONFIG_KEYS])
-        self.ref = self.node_get_member(node, str, 'ref', None)
+        self.ref = node.get_str('ref', None)
 
     def preflight(self):
         pass