Improve ecobee service schemas (#26955)

* Validate date and time in create vaction

Improve validation with utility functions.

* Improve validate ATTR_VACATION_NAME

* Add tests for ecobee.util functions

* Revise tests as standalone functions

tests/components/ecobee/test_util.py

@@ -0,0 +1,35 @@
+"""Tests for the ecobee.util module."""
+import pytest
+import voluptuous as vol
+
+from homeassistant.components.ecobee.util import ecobee_date, ecobee_time
+
+
+def test_ecobee_date_with_valid_input():
+    """Test that the date function returns the expected result."""
+    test_input = "2019-09-27"
+
+    assert ecobee_date(test_input) == test_input
+
+
+def test_ecobee_date_with_invalid_input():
+    """Test that the date function raises the expected exception."""
+    test_input = "20190927"
+
+    with pytest.raises(vol.Invalid):
+        ecobee_date(test_input)
+
+
+def test_ecobee_time_with_valid_input():
+    """Test that the time function returns the expected result."""
+    test_input = "20:55:15"
+
+    assert ecobee_time(test_input) == test_input
+
+
+def test_ecobee_time_with_invalid_input():
+    """Test that the time function raises the expected exception."""
+    test_input = "20:55"
+
+    with pytest.raises(vol.Invalid):
+        ecobee_time(test_input)