NPI-3458 further refinement of SolutionType classes, addition of unit…

… tests

gnssanalysis/solution_types.py

@@ -5,6 +5,7 @@
 
 
 # Abstract base class. Leverages above Immutable metaclass to prevent its (effectively) constants, from being modified.
+# Note that this doesn't prevent everything. For example, the contents of a list can still be changed.
 class SolutionType(metaclass=EnumMetaProperties):
     name: str
     long_name: str
@@ -86,14 +87,17 @@ class UNK(SolutionType):
     long_name = "unknown solution type"
 
 
-class SolutionTypes:
+class SolutionTypes(metaclass=EnumMetaProperties):
     """
     Defines valid solution type identifiers specified for use in the IGS long product filename convention v2:
     https://files.igs.org/pub/resource/guidelines/Guidelines_For_Long_Product_Filenames_in_the_IGS_v2.0.pdf
 
     Also see here for information on session lengths of products pubished by IGS: https://igs.org/products/#about
     """
 
+    def __init__(self):
+        raise Exception("This is intended to act akin to an enum. Don't instantiate it.")
+
     FIN = FIN  # Final products
     NRT = NRT  # Near-Real Time (between ULT and RTS)
     PRD = PRD  # Predicted products

tests/test_solution_type.py

@@ -0,0 +1,51 @@
+import unittest
+
+from gnssanalysis.solution_types import SolutionType, SolutionTypes
+
+
+class TestSp3(unittest.TestCase):
+    def test_shortname_to_solution_type(self):
+        self.assertEqual(SolutionTypes.from_name("ULT"), SolutionTypes.ULT)
+        self.assertEqual(SolutionTypes.from_name("RAP"), SolutionTypes.RAP)
+        self.assertEqual(SolutionTypes.from_name("UNK"), SolutionTypes.UNK)
+        # AssertRaises can be used either as a context manager, or by breaking out the function arguments.
+        # Note we're not *calling* the function, we're passing the function *so it can be called* by the handler.
+        self.assertRaises(ValueError, SolutionTypes.from_name, name="noo")
+        self.assertRaises(ValueError, SolutionTypes.from_name, name="rapid")
+        self.assertRaises(ValueError, SolutionTypes.from_name, name="")
+        self.assertRaises(ValueError, SolutionTypes.from_name, name=" ")
+
+    def test_immutability(self):
+        def update_base_attribute():
+            SolutionType.name = "someNewValue"
+
+        # Note that *contents* of a list can still be modified, despite the more general
+        # protections provided by the metaclass
+
+        def update_enum_attribute_new():
+            SolutionTypes.ULT.name = "someBogusValue"
+
+        self.assertRaises(AttributeError, update_base_attribute)
+        self.assertRaises(AttributeError, update_enum_attribute_new)
+
+        def instantiate_solution_generic():
+            SolutionType()
+
+        def instantiate_solution_specific():
+            SolutionTypes.RAP()
+
+        def instantiate_solution_helper():
+            SolutionTypes()
+
+        self.assertRaises(Exception, instantiate_solution_generic)
+        self.assertRaises(Exception, instantiate_solution_specific)
+        self.assertRaises(Exception, instantiate_solution_helper)
+
+    def test_equality(self):
+        self.assertEqual(SolutionTypes.RAP, SolutionTypes.RAP, "References to same solution type class should be equal")
+        self.assertEqual(
+            SolutionTypes.from_name("RAP"),
+            SolutionTypes.from_name("rap"),
+            "from_name should give equal results each time, also regardless of case of input",
+        )
+        self.assertNotEqual(SolutionTypes.RAP, SolutionTypes.UNK, "Non-matching solution types should be unequal")