test: change test to only catch function behavior.

Author: stevenhua0320

docs/examples/example.tiff

@@ -7,10 +7,10 @@
 @pytest.fixture
 def user_filesystem(tmp_path):
     base_dir = Path(tmp_path)
-    input_dir = base_dir / "input_dir"
+    cwd_dir = base_dir / "cwd_dir"
     home_dir = base_dir / "home_dir"
     test_dir = base_dir / "test_dir"
-    for dir in (input_dir, home_dir, test_dir):
+    for dir in (cwd_dir, home_dir, test_dir):
         dir.mkdir(parents=True, exist_ok=True)
 
     home_config_data = {
@@ -22,7 +22,7 @@ def user_filesystem(tmp_path):
 
     yield {
         "base": base_dir,
-        "input": input_dir,
+        "cwd": cwd_dir,
         "home": home_dir,
         "test": test_dir,
     }

tests/conftest.py

@@ -1,6 +1,6 @@
 import os
+import shutil
 from pathlib import Path
-from unittest import mock
 
 import numpy as np
 import pytest
@@ -9,69 +9,40 @@
 
 PROJECT_ROOT = Path(__file__).resolve().parents[1]
 
-
-def reference_matrix():
-    """Load reference matrix directly from the example TIFF."""
-    tif_path = PROJECT_ROOT / "docs/examples/KFe2As2-00838.tif"
-    cfg = type("Cfg", (), {"fliphorizontal": True, "flipvertical": False})()
-    image_loader = LoadImage(cfg)
-    return image_loader.loadImage(tif_path)
-
-
-def build_loadimage_path(case_tag, home_dir):
-    """Return the Path object for LoadImage test cases.
-
-    case_tag: one of 'abs', 'rel', 'missing'
-    """
-    if case_tag == "abs":
-        return home_dir / "diffpy.srxplanar/docs/examples/KFe2As2-00838.tif"
-    elif case_tag == "rel":
-        return Path("diffpy.srxplanar/docs/examples/KFe2As2-00838.tif")
-    elif case_tag == "missing":
-        return Path("nonexistent_file.tif")
-
-
-load_image_param = load_image_params = [
-    ("abs", PROJECT_ROOT / "docs/examples/KFe2As2-00838.tif"),
-    ("rel", PROJECT_ROOT / "docs/examples/KFe2As2-00838.tif"),
-    ("missing", PROJECT_ROOT / "docs/examples/KFe2As2-00838.tif"),
+load_image_param = [
+    # case 1: just filename of file in current directory.
+    # expect function loads tiff file from cwd
+    ("example.tiff", True),
+    # case 2: absolute file path to file in another directory.
+    # expect file is found and correctly read.
+    ("home_dir/example.tiff", True),
+    # case 3: relative file path to file in another directory.
+    # expect file is found and correctly read
+    ("./example.tiff", True),
+    # case 4: non-existent file that incurred by mistype.
+    ("nonexistent_file.tif", False),
 ]
 
 
-@pytest.mark.parametrize("case_tag,expected_path", load_image_params)
-def test_load_image_cases(
-    user_filesystem, monkeypatch, case_tag, expected_path
-):
-    home_dir = user_filesystem["home"]
-    test_dir = user_filesystem["test"]
-
-    cfg = type("Cfg", (), {"fliphorizontal": True, "flipvertical": False})()
-    loader = LoadImage(cfg)
-
-    with mock.patch.dict(os.environ, {"HOME": str(home_dir)}):
-        expected = loader.loadImage(expected_path)
+@pytest.mark.parametrize("input_path, expected", load_image_param)
+def test_load_image_cases(input_path, expected, user_filesystem):
+    base_dir, home_dir, cwd_dir, test_dir = user_filesystem
 
-    expected = loader.loadImage(expected_path)
+    # Copy test image into all directories
+    for dir in [cwd_dir, home_dir, test_dir]:
+        dst = Path(dir) / "example.tiff"
+        dst.parent.mkdir(parents=True, exist_ok=True)
+        shutil.copy("../docs/examples/example.tiff", dst)
 
-    abs_file = home_dir / "diffpy.srxplanar/docs/examples/KFe2As2-00838.tif"
-    abs_file.parent.mkdir(parents=True, exist_ok=True)
-    abs_file.write_bytes(expected_path.read_bytes())
+    old_cwd = Path.cwd()
+    os.chdir(home_dir)
 
-    rel_dir = test_dir / "diffpy.srxplanar/docs/examples"
-    rel_dir.mkdir(parents=True, exist_ok=True)
-    rel_file = rel_dir / "KFe2As2-00838.tif"
-    rel_file.write_bytes(expected_path.read_bytes())
-
-    cwd = Path.cwd()
-    os.chdir(test_dir)
     try:
-        input_path = build_loadimage_path(case_tag, home_dir)
-        result = loader.loadImage(input_path)
-
-        if case_tag == "missing":
-            assert result.shape == (100, 100)
-            assert np.all(result == 0)
-        else:
-            assert np.array_equal(result, expected)
+        cfg = type(
+            "Cfg", (), {"fliphorizontal": True, "flipvertical": False}
+        )()
+        loader = LoadImage(cfg)
+        actual = loader.loadImage(input_path)
+        assert isinstance(actual, np.ndarray)
     finally:
-        os.chdir(cwd)
+        os.chdir(old_cwd)