per #2244, add unit tests for diff utility

internal/tests/pytests/util/diff_util/test_diff_util.py

@@ -0,0 +1,95 @@
+import pytest
+
+import os
+import shutil
+import uuid
+
+from metplus.util.diff_util import dirs_are_equal
+from metplus.util import mkdir_p
+
+test_output_dir = os.path.join(os.environ['METPLUS_TEST_OUTPUT_BASE'],
+                               'test_output')
+
+stat_header = 'VERSION MODEL DESC     FCST_LEAD FCST_VALID_BEG  FCST_VALID_END  OBS_LEAD OBS_VALID_BEG   OBS_VALID_END   FCST_VAR FCST_UNITS FCST_LEV OBS_VAR OBS_UNITS OBS_LEV OBTYPE VX_MASK INTERP_MTHD INTERP_PNTS FCST_THRESH OBS_THRESH COV_THRESH ALPHA LINE_TYPE'
+mpr_line_1 = 'V11.1.0 HRRR  ALL_1.25 120000    20220701_200000 20220701_200000 000000   20220701_200000 20220701_200000 HPBL     m          L0       HPBL    m         L0      ADPSFC DENVER  BILIN       4           NA          NA         NA         NA    MPR       5    4       DENVER            39.78616    -104.41425       0         0       2160.80324 1498.06763 AMDAR NA NA NA'
+mpr_line_2 = 'V11.1.0 HRRR  ALL_1.25 120000    20220701_200000 20220701_200000 000000   20220701_200000 20220701_200000 HPBL     m          L0       HPBL    m         L0      ADPSFC DENVER  BILIN       4           NA          NA         NA         NA    MPR       5    4       DENVER            39.78616    -104.41425       0         0       2160.80324 1498.05994 AMDAR NA NA NA'
+
+
+def create_diff_files(files_a, files_b):
+    unique_id = str(uuid.uuid4())[0:8]
+    dir_a = os.path.join(test_output_dir, f'diff_{unique_id}', 'a')
+    dir_b = os.path.join(test_output_dir, f'diff_{unique_id}', 'b')
+    mkdir_p(dir_a)
+    mkdir_p(dir_b)
+    write_files(dir_a, files_a)
+    write_files(dir_b, files_b)
+    return dir_a, dir_b
+
+
+def write_files(dirname, files):
+    for filename, lines in files.items():
+        filepath = os.path.join(dirname, filename)
+        if os.path.sep in filename:
+            parent_dir = os.path.dirname(filepath)
+            mkdir_p(parent_dir)
+
+        with open(filepath, 'w') as file_handle:
+            for line in lines:
+                file_handle.write(f'{line}\n')
+
+
+@pytest.mark.util
+def test_diff_dirs_both_empty():
+    a_dir, b_dir = create_diff_files({}, {})
+    assert dirs_are_equal(a_dir, b_dir)
+    shutil.rmtree(os.path.dirname(a_dir))
+
+
+@pytest.mark.util
+def test_diff_dirs_one_empty():
+    test_files = {'filename.txt': ['some', 'text']}
+    for empty_one in ('a', 'b'):
+        a_files = b_files = {}
+        if empty_one == 'a':
+            b_files = test_files
+        else:
+            a_files = test_files
+        a_dir, b_dir = create_diff_files(a_files, b_files)
+        assert not dirs_are_equal(a_dir, b_dir)
+        shutil.rmtree(os.path.dirname(a_dir))
+
+
+@pytest.mark.util
+def test_diff_files_both_empty():
+    test_files = {'filename.txt': []}
+    a_dir, b_dir = create_diff_files(test_files, test_files)
+    assert dirs_are_equal(a_dir, b_dir)
+    shutil.rmtree(os.path.dirname(a_dir))
+
+
+@pytest.mark.util
+def test_diff_files_one_empty():
+    filename = 'filename.txt'
+    test_content = ['some', 'text']
+    for empty_one in ('a', 'b'):
+        a_files = {filename: []}
+        b_files = {filename: []}
+        if empty_one == 'a':
+            b_files[filename].extend(test_content)
+        else:
+            a_files[filename].extend(test_content)
+        a_dir, b_dir = create_diff_files(a_files, b_files)
+        assert not dirs_are_equal(a_dir, b_dir)
+        shutil.rmtree(os.path.dirname(a_dir))
+
+
+@pytest.mark.util
+def test_diff_stat_header_columns():
+    filename = 'filename.stat'
+    a_content = [stat_header, mpr_line_1]
+    b_content = [f'{stat_header} NEW_COLUMN', mpr_line_1]
+    a_files = {filename: [a_content]}
+    b_files = {filename: [b_content]}
+    a_dir, b_dir = create_diff_files(a_files, b_files)
+    assert not dirs_are_equal(a_dir, b_dir)
+    shutil.rmtree(os.path.dirname(a_dir))