NPI-3689 add initial unit tests for IAU2000 variant selection logic

tests/test_download.py

@@ -0,0 +1,162 @@
+# Tests for gn_download.py
+
+import datetime
+from pathlib import Path
+from pyfakefs.fake_filesystem_unittest import TestCase
+from datetime import datetime, timedelta
+
+from gnssanalysis.gn_download import get_iau2000_file_variants_for_dates, download_iau2000_variant
+
+
+class TestIAU2000Selection(TestCase):
+
+    def test_iau2000_variant_selection(self) -> None:
+
+        # variants = Literal["standard", "daily"]
+        now = datetime.now()
+
+        date_100_days_ago: datetime = now - timedelta(days=100)  # Must use standard file
+        date_90_days_ago: datetime = now - timedelta(days=90)  # Must use standard file (boundary)
+        date_89_days_ago: datetime = now - timedelta(days=89)  # Must use standard file (safety boundary)
+        date_8_weeks_ago: datetime = now - timedelta(weeks=8)  # Can use either file (preference dictates)
+        date_2_weeks_ago: datetime = now - timedelta(weeks=2)  # Can use either file (preference dictates)
+        date_8_days_ago: datetime = now - timedelta(days=8)  # Must use daily file (safety boundary)
+        date_7_days_ago: datetime = now - timedelta(days=7)  # Must use daily file (boundary)
+        date_3_days_ago: datetime = now - timedelta(days=3)  # Must use daily file
+        date_1_day_ago: datetime = now - timedelta(days=1)  # Probably ok, must use daily file
+        date_today: datetime = now  # Edge case, probably should raise an exception
+        date_1_day_in_future: datetime = now + timedelta(days=1)  # Should raise exception
+
+        # --- Tests with both start and end date specified ---
+
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(start_epoch=date_100_days_ago, end_epoch=date_90_days_ago),
+            set(["standard"]),
+            "Start and end both dated older than 90 days, should use standard file",
+        )
+
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(start_epoch=date_100_days_ago, end_epoch=date_89_days_ago),
+            set(["standard"]),
+            "Range with border, should choose conservative option (89 day boundary should choose standard file)",
+        )
+
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(start_epoch=date_89_days_ago, end_epoch=date_89_days_ago),
+            set(["standard"]),
+            "0-length range on 89 days should should choose standard file",
+        )
+
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(start_epoch=date_89_days_ago, end_epoch=date_3_days_ago),
+            set(["standard", "daily"]),
+            "Range on 89 days should conservatively include standard file (even if other date causes selection of daily file as well)",
+        )
+
+        # Option 1: no preference
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(start_epoch=date_100_days_ago, end_epoch=date_7_days_ago),
+            set(["standard", "daily"]),
+            "Range touching 7 days ago should conservatively include daily file, regardless of preference (default / not stated) and other date in range",
+        )
+
+        # Option 2: prefer standard
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(
+                start_epoch=date_100_days_ago, end_epoch=date_7_days_ago, preferred_variant="standard"
+            ),
+            set(["standard", "daily"]),
+            "Range touching 7 days ago should conservatively include daily file, regardless of preference (standard) and other date in range",
+        )
+
+        # Option 3: prefer daily (default at time of writing)
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(
+                start_epoch=date_100_days_ago, end_epoch=date_7_days_ago, preferred_variant="daily"
+            ),
+            set(["standard", "daily"]),
+            "Range touching 7 days ago should conservatively include daily file, regardless of preference (daily) and other date in range",
+        )
+
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(start_epoch=date_8_days_ago, end_epoch=date_3_days_ago),
+            set(["daily"]),
+            "Recent range should always pick daily file when on boundary, regardless of preference (not specified)",
+        )
+
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(
+                start_epoch=date_8_days_ago, end_epoch=date_3_days_ago, preferred_variant="standard"
+            ),
+            set(["daily"]),
+            "Recent range should always pick daily file when on boundary, regardless of preference (standard)",
+        )
+
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(
+                start_epoch=date_8_days_ago, end_epoch=date_3_days_ago, preferred_variant="daily"
+            ),
+            set(["daily"]),
+            "Recent range should always pick daily file when on boundary, regardless of preference (daily)",
+        )
+
+        # --- Tests leveraging variant preference overrride ---
+
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(
+                start_epoch=date_8_weeks_ago, end_epoch=date_2_weeks_ago, preferred_variant="daily"
+            ),
+            set(["daily"]),
+            "Date ranges which are version agnostic should fall back on the preference specified (daily)",
+        )
+
+        self.assertEqual(
+            get_iau2000_file_variants_for_dates(
+                start_epoch=date_8_weeks_ago, end_epoch=date_2_weeks_ago, preferred_variant="standard"
+            ),
+            set(["standard"]),
+            "Date ranges which are version agnostic should fall back on the preference specified (standard)",
+        )
+
+        # --- Tests focussing on boundary dates (not all of them) ---
+        self.assertTrue(
+            "daily"
+            in get_iau2000_file_variants_for_dates(
+                start_epoch=date_2_weeks_ago, end_epoch=date_1_day_ago, preferred_variant="standard"
+            ),
+            "Date range ending at yesterday should be allowable, but must utilise daily file",
+        )
+
+        # --- Tests with start or end date only ---
+
+        self.assertTrue(
+            "daily" in get_iau2000_file_variants_for_dates(start_epoch=date_8_weeks_ago, preferred_variant="standard"),
+            "Open ended range should conservatively assume the range may extend past a boundary",
+        )
+
+        self.assertTrue(
+            "standard" in get_iau2000_file_variants_for_dates(end_epoch=date_3_days_ago, preferred_variant="daily"),
+            "Open ended range should conservatively assume the range may extend past a boundary",
+        )
+
+
+        # --- Tests for invalid values ---
+        # Invalid argument
+        with self.assertRaises(Exception):
+            get_iau2000_file_variants_for_dates()
+            # Start or end date must be provided.
+
+        # Invalid dates
+        # Dates must be before today / can't be in the future. We allow about a day for the data source to update.
+        with self.assertRaises(ValueError):
+            get_iau2000_file_variants_for_dates(start_epoch=now)
+
+        with self.assertRaises(ValueError):
+            get_iau2000_file_variants_for_dates(end_epoch=now)
+
+        with self.assertRaises(ValueError):
+            get_iau2000_file_variants_for_dates(start_epoch=date_1_day_in_future)
+
+        with self.assertRaises(ValueError):
+            get_iau2000_file_variants_for_dates(end_epoch=date_1_day_in_future)
+