Add tests for environmental variables interpolation support

tests/unit/credentials/test_reader.py

@@ -31,6 +31,24 @@ def creds_yaml_bad_url():
 """
 
 
+@pytest.fixture
+def creds_yaml_env_variables():
+    return """
+secrets:
+    local_ftp: ftp://${USER}:${PASSWORD}@local.com
+    remote_db: postgresql://${USER_DB}:${PASSWORD_DB}@db.com/database
+"""
+
+
+@pytest.fixture
+def creds_yaml_bad_env_variables():
+    return """
+secrets:
+    local_ftp: ftp://${FAKE_USER}:${FAKE_PASSWORD}@local.com
+    remote_db: postgresql://${FAKE_USER_DB}:${FAKE_PASSWORD_DB}@db.com/database
+"""
+
+
 def test_bad_yaml():
     with pytest.raises(TentaclioFileError):
         data = io.StringIO("sadfsaf")
@@ -62,3 +80,29 @@ def test_credentials_bad_url(creds_yaml_bad_url):
     data = io.StringIO(creds_yaml_bad_url)
     with pytest.raises(Exception):
         reader.add_credentials_from_reader(injection.CredentialsInjector(), data)
+
+
+@pytest.mark.parametrize(
+    "url, expected",
+    [
+        ("ftp://local.com/file.txt", "ftp://user:[email protected]/file.txt"),
+        ("postgresql://db.com/database", "postgresql://user_db:[email protected]/database"),
+    ],
+)
+def test_credentials_env_variable(url, expected, creds_yaml_env_variables, monkeypatch):
+    monkeypatch.setenv('USER', 'user')
+    monkeypatch.setenv('USER_DB', 'user_db')
+    monkeypatch.setenv('PASSWORD', 'password')
+    monkeypatch.setenv('PASSWORD_DB', 'password_db')
+
+    data = io.StringIO(creds_yaml_env_variables)
+    injector = reader.add_credentials_from_reader(injection.CredentialsInjector(), data)
+
+    result = injector.inject(urls.URL(url))
+    assert result == urls.URL(expected)
+
+
+def test_credentials_bad_env_variable(creds_yaml_bad_env_variables):
+    data = io.StringIO(creds_yaml_bad_env_variables)
+    with pytest.raises(EnvironmentError):
+        reader.add_credentials_from_reader(injection.CredentialsInjector(), data)