Create decimal parameter, add null test

test/residual_test/residual_test.py

 from numpy.testing import assert_almost_equal
 import pytest
 
-from geomagio.residual import calculate, Reading, SpreadsheetAbsolutesFactory
+from obspy.core import UTCDateTime
+from geomagio.residual import (
+    calculate,
+    Reading,
+    SpreadsheetAbsolutesFactory,
+    WebAbsolutesFactory,
+)
 
 
-def assert_readings_equal(expected: Reading, actual: Reading):
+def assert_readings_equal(expected: Reading, actual: Reading, decimal: float):
     """
     Compares calculation actuals to expected absolutes from spreadsheet
     """
@@ -13,24 +19,26 @@ def assert_readings_equal(expected: Reading, actual: Reading):
     assert_almost_equal(
         [expected_absolutes["H"].absolute, expected_absolutes["H"].baseline],
         [actual_absolutes["H"].absolute, actual_absolutes["H"].baseline],
-        decimal=1,
+        decimal=decimal,
         verbose=True,
     )
     assert_almost_equal(
         [expected_absolutes["D"].absolute, expected_absolutes["D"].baseline],
         [actual_absolutes["D"].absolute, actual_absolutes["D"].baseline],
-        decimal=1,
+        decimal=decimal,
         verbose=True,
     )
     assert_almost_equal(
         [expected_absolutes["Z"].absolute, expected_absolutes["Z"].baseline],
         [actual_absolutes["Z"].absolute, actual_absolutes["Z"].baseline],
-        decimal=1,
+        decimal=decimal,
         verbose=True,
     )
-    assert_almost_equal(
-        expected.scale_value, actual.scale_value, decimal=1, verbose=True
-    )
+
+    if expected.scale_value:
+        assert_almost_equal(
+            expected.scale_value, actual.scale_value, decimal=1, verbose=True
+        )
 
 
 def compare_spreadsheet_absolutes(path):
@@ -44,6 +52,17 @@ def compare_spreadsheet_absolutes(path):
     return reading
 
 
+def compare_null_absolutes(observatory, starttime, endtime):
+    """
+    Tests functionality of WebAbsolutesFactory and recalculation of absolutes
+    """
+    # establish SpreadsheetAbsolutesFactory for reading test data from Excel
+    waf = WebAbsolutesFactory()
+    # Read spreadsheet containing test data
+    reading = waf.get_readings(observatory, starttime, endtime)[0]
+    return reading
+
+
 def test_DED_20140952332():
     """
     Compare calulations to original absolutes obejct from Spreadsheet.
@@ -53,7 +72,7 @@ def test_DED_20140952332():
     # gather absolute from DED test data and recalculate
     reading = compare_spreadsheet_absolutes(path="etc/residual/DED-20140952332.xlsm")
     # test results with original spreadsheet values
-    assert_readings_equal(reading, calculate(reading))
+    assert_readings_equal(reading, calculate(reading), 1)
 
 
 def test_BRW_20133650000():
@@ -65,4 +84,18 @@ def test_BRW_20133650000():
     # gather absolute from DED test data and recalculate
     reading = compare_spreadsheet_absolutes(path="etc/residual/BRW-20133650000.xlsm")
     # test results with original spreadsheet values
-    assert_readings_equal(reading, calculate(reading))
+    assert_readings_equal(reading, calculate(reading), 1)
+
+
+def test_BOU_20200422():
+    """
+    Compare calulations to original absolutes obejct from web absolutes.
+    Tests gathering of BOU's metadata for use by calculations.
+    Tests calculations for null method measurements in units of DMS.
+    """
+    reading = compare_null_absolutes(
+        observatory="BOU",
+        starttime=UTCDateTime("2020-04-22T00:00:00Z"),
+        endtime=UTCDateTime("2020-04-23T00:00:00Z"),
+    )
+    assert_readings_equal(reading, calculate(reading), 0.1)