test: implement simple sugar test

test/test_sugar.py

@@ -0,0 +1,61 @@
+import pytest
+
+from otk.parse.document import Omnifest
+from otk.transform.context import Context
+from otk.transform import resolve
+from otk.error import TransformDirectiveTypeError
+
+
+def test_simple_sugar():
+    data = """
+otk.version: 1
+otk.define:
+  variable: "foo"
+
+my_var: ${variable}
+"""
+
+    context = Context()
+    omnifest_under_test = Omnifest.from_yaml_bytes(data).to_tree()
+
+    omnifest_result = resolve(context, omnifest_under_test)
+
+    assert omnifest_result['my_var'] == "foo"
+
+
+def test_simple_sugar_tree():
+    data = """
+otk.version: 1
+otk.define:
+  variable:
+    - 1
+    - 2
+
+my_var: ${variable}
+"""
+
+    context = Context()
+    omnifest_under_test = Omnifest.from_yaml_bytes(data).to_tree()
+
+    omnifest_result = resolve(context, omnifest_under_test)
+
+    assert omnifest_result['my_var'] == [1, 2]
+
+
+def test_simple_sugar_tree_fail():
+    data = """
+otk.version: 1
+otk.define:
+  variable:
+    - 1
+    - 2
+
+my_var: my_prefix_${variable}
+"""
+    expected_error = 'string sugar resolves to an incorrect type, expected int, float, or str but got %r'
+
+    context = Context()
+    omnifest_under_test = Omnifest.from_yaml_bytes(data).to_tree()
+
+    with pytest.raises(TransformDirectiveTypeError, match=expected_error):
+        resolve(context, omnifest_under_test)