refactoring

test/unit_tests/coordinate_transformer_test.py

@@ -12,15 +12,67 @@ from image_prediction.transformer.transformers.coordinate.pdfnet import PDFNetCo
 from test.conftest import array_to_image, add_image
 
 
-@pytest.fixture
+@pytest.mark.parametrize("coordinate_system", ["fpdf"])
-def coordinate_test_image():
+def test_fpdf_coordinate_transformer(position_metadata_in_given_system, position_metadata_in_reference_system):
-    return array_to_image(np.zeros(shape=(100, 100, 3)))
+    """We use FPDF's coordinate system as the reference system (arbitrarily). Hence, FPDFCoordinateTransformer
+    actually does not do anything. This test merely documents the fact, that FPDF is the reference system.
+    """
+    transformer = FPDFCoordinateTransformer()
+    assert transformer.forward(position_metadata_in_given_system) == position_metadata_in_reference_system
+    assert transformer.backward(position_metadata_in_reference_system) == position_metadata_in_given_system
+
+    assert (
+            compose(transformer.backward, transformer.forward)(position_metadata_in_reference_system)
+            == position_metadata_in_reference_system
+    )
+
+
+@pytest.mark.parametrize("coordinate_system", ["fitz"])
+def test_fitz_coordinate_transformer(position_metadata_in_given_system, position_metadata_in_reference_system):
+    """How I inferred the transformation:
+
+    - extract images from coordinate_test_fpdf with ParsablePDFImageExtractor (see test_parsable_pdf_image_extractor)
+    - Compare position_metadata_in_given_system (fitz) with position_metadata_in_reference_system (fpdf)
+    - Observe that they are identical
+    """
+    transformer = FitzCoordinateTransformer()
+    assert transformer.forward(position_metadata_in_given_system) == position_metadata_in_reference_system
+    assert transformer.backward(position_metadata_in_reference_system) == position_metadata_in_given_system
+
+    assert (
+            compose(transformer.backward, transformer.forward)(position_metadata_in_reference_system)
+            == position_metadata_in_reference_system
+    )
+
+
+@pytest.mark.parametrize("coordinate_system", ["pdfnet"])
+def test_pdfnet_coordinate_transformer(position_metadata_in_given_system, position_metadata_in_reference_system):
+    """How I inferred the transformation:
+
+    - save coordinate_test_fpdf to disk as file f
+    - draw boxes for position_metadata_in_reference_system in f with draw_metadata_box
+    - save annotated pdf as file g
+    - look at discrepancy between the black square and the red box in g
+    """
+    transformer = PDFNetCoordinateTransformer()
+
+    assert transformer.forward(position_metadata_in_reference_system) == position_metadata_in_given_system
+    assert transformer.backward(position_metadata_in_given_system) == position_metadata_in_reference_system
+
+    assert (
+            compose(transformer.backward, transformer.forward)(position_metadata_in_reference_system)
+            == position_metadata_in_reference_system
+    )
 
 
 @pytest.fixture
-def coordinate_test_fpdf():
+def position_metadata_in_given_system(corner, corner2metadata_in_given_system):
-    pdf = fpdf.FPDF(unit="pt", format=(300, 300))
+    return corner2metadata_in_given_system[corner]
-    return pdf
+
+
+@pytest.fixture
+def position_metadata_in_reference_system(corner, corner2metadata_in_reference_system):
+    return corner2metadata_in_reference_system[corner]
 
 
 @pytest.fixture(params=["top_left", "bottom_left", "bottom_right", "top_right"])
@@ -28,11 +80,27 @@ def corner(request):
     return request.param
 
 
-def set_coords(metadata, x1, y1, x2, y2):
+@pytest.fixture
-    metadata.update({Info.X1: x1, Info.Y1: y1, Info.X2: x2, Info.Y2: y2})
+def corner2metadata_in_given_system(coordinate_system):
+    if coordinate_system == "fpdf":
+        return get_fpdf_corner_metadat()
+
+    elif coordinate_system == "fitz":
+        return get_fitz_corner_metadat()
+
+    elif coordinate_system == "pdfnet":
+        return get_pdfnet_corner_metadata()
+
+    else:
+        raise ValueError(f"Unknown coordinate system: {coordinate_system}")
 
 
-def get_fpdf_coordinates(corner):
+@pytest.fixture
+def corner2metadata_in_reference_system():
+    return get_fpdf_corner_metadat()
+
+
+def get_fpdf_corner_metadat():
     """Origin top left, y1 <= y2; all coords on page are positive
     (0,0)--+--(2,0)--+
       |////|    |////|
@@ -42,31 +110,19 @@ def get_fpdf_coordinates(corner):
       |////|    |////|
       +--(1,3)  +--(3,3)
     """
-    metadata = base_position_metadata()
+    return {
-
+        "top_left": get_metadata_for_coords(0, 0, 100, 100),
-    if corner == "top_left":
+        "bottom_left": get_metadata_for_coords(0, 200, 100, 300),
-        set_coords(metadata, 0, 0, 100, 100)
+        "bottom_right": get_metadata_for_coords(200, 200, 300, 300),
-
+        "top_right": get_metadata_for_coords(200, 0, 300, 100)
-    elif corner == "bottom_left":
+    }
-        set_coords(metadata, 0, 200, 100, 300)
-
-    elif corner == "bottom_right":
-        set_coords(metadata, 200, 200, 300, 300)
-
-    elif corner == "top_right":
-        set_coords(metadata, 200, 0, 300, 100)
-
-    else:
-        raise ValueError(f"No coordinates specified for corner {corner}.")
-
-    return metadata
 
 
-def get_fitz_coordinates(corner):
+def get_fitz_corner_metadat():
-    return get_fpdf_coordinates(corner)
+    return get_fpdf_corner_metadat()
 
 
-def get_pdfnet_coordinates(corner):
+def get_pdfnet_corner_metadata():
     """Origin bottom left, y1 <= y2; all coords on page are positive
       +---(1,3) +--(3,3)
       |////|    |////|
@@ -76,23 +132,17 @@ def get_pdfnet_coordinates(corner):
       |////|    |////|
     (0,0)--+  (2,0)--+
     """
+    return {
+        "top_left": get_metadata_for_coords(0, 200, 100, 300),
+        "bottom_left": get_metadata_for_coords(0, 0, 100, 100),
+        "bottom_right": get_metadata_for_coords(200, 0, 300, 100),
+        "top_right": get_metadata_for_coords(200, 200, 300, 300),
+    }
+
+
+def get_metadata_for_coords(x1, y1, x2, y2):
     metadata = base_position_metadata()
-
+    metadata.update({Info.X1: x1, Info.Y1: y1, Info.X2: x2, Info.Y2: y2})
-    if corner == "top_left":
-        set_coords(metadata, 0, 200, 100, 300)
-
-    elif corner == "bottom_left":
-        set_coords(metadata, 0, 0, 100, 100)
-
-    elif corner == "bottom_right":
-        set_coords(metadata, 200, 0, 300, 100)
-
-    elif corner == "top_right":
-        set_coords(metadata, 200, 200, 300, 300)
-
-    else:
-        raise ValueError(f"No coordinates specified for corner {corner}.")
-
     return metadata
 
 
@@ -110,32 +160,7 @@ def base_position_metadata(width=100, height=100):
     }
 
 
-@pytest.fixture(params=["list", "dict"])
+# utils not needed for tests but for inferring new coordinates systems:
-def coordinate_type(request):
-    return request.param
-
-
-@pytest.fixture
-def position_metadata_in_given_system(corner, coordinate_system, coordinate_type):
-    if coordinate_system == "fpdf":
-        coordinates = get_fpdf_coordinates(corner)
-
-    elif coordinate_system == "fitz":
-        coordinates = get_fitz_coordinates(corner)
-
-    elif coordinate_system == "pdfnet":
-        coordinates = get_pdfnet_coordinates(corner)
-
-    else:
-        raise ValueError(f"Unknown coordinate system: {coordinate_system}")
-
-    return [coordinates, coordinates] if coordinate_type == "list" else coordinates
-
-
-@pytest.fixture
-def position_metadata_in_reference_system(corner, coordinate_type):
-    coordinates = get_fpdf_coordinates(corner)
-    return [coordinates, coordinates] if coordinate_type == "list" else coordinates
 
 
 @pytest.fixture
@@ -144,60 +169,22 @@ def coordinate_test_pdf(position_metadata_in_given_system, coordinate_test_image
     return coordinate_test_fpdf.output(dest="S").encode("latin1")
 
 
+@pytest.fixture
+def coordinate_test_image():
+    return array_to_image(np.zeros(shape=(100, 100, 3)))
+
+
+@pytest.fixture
+def coordinate_test_fpdf():
+    pdf = fpdf.FPDF(unit="pt", format=(300, 300))
+    return pdf
+
+
 @pytest.fixture
 def coordinate_test_page_image(coordinate_test_pdf):
     return pdf2image.convert_from_bytes(coordinate_test_pdf)[0]
 
 
-@pytest.mark.parametrize("coordinate_system", ["fpdf"])
+@pytest.fixture(params=["list", "dict"])
-def test_fpdf_coordinate_transformer(position_metadata_in_given_system, position_metadata_in_reference_system):
+def coordinate_type(request):
-    """We use FPDF's coordinate system as the reference system (arbitrarily). Hence, FPDFCoordinateTransformer
+    return request.param
-    actually does not do anything. This test merely documents the fact, that FPDF is the reference system.
-    """
-    transformer = FPDFCoordinateTransformer()
-    assert transformer.forward(position_metadata_in_given_system) == position_metadata_in_reference_system
-    assert transformer.backward(position_metadata_in_reference_system) == position_metadata_in_given_system
-
-    assert (
-        compose(transformer.backward, transformer.forward)(position_metadata_in_reference_system)
-        == position_metadata_in_reference_system
-    )
-
-
-@pytest.mark.parametrize("coordinate_system", ["fitz"])
-def test_fitz_coordinate_transformer(position_metadata_in_given_system, position_metadata_in_reference_system):
-    """How I inferred the transformation:
-
-    - extract images from coordinate_test_fpdf with ParsablePDFImageExtractor (see test_parsable_pdf_image_extractor)
-    - Compare position_metadata_in_given_system (fitz) with position_metadata_in_reference_system (fpdf)
-    - Observe that they are identical
-    """
-    transformer = FitzCoordinateTransformer()
-    assert transformer.forward(position_metadata_in_given_system) == position_metadata_in_reference_system
-    assert transformer.backward(position_metadata_in_reference_system) == position_metadata_in_given_system
-
-    assert (
-        compose(transformer.backward, transformer.forward)(position_metadata_in_reference_system)
-        == position_metadata_in_reference_system
-    )
-
-
-@pytest.mark.parametrize("coordinate_system", ["pdfnet"])
-def test_pdfnet_coordinate_transformer(position_metadata_in_given_system, position_metadata_in_reference_system):
-    """How I inferred the transformation:
-
-    - save coordinate_test_fpdf to disk as file f
-    - draw boxes for position_metadata_in_reference_system in f with draw_metadata_box
-    - save annotated pdf as file g
-    - look at discrepancy between the black square and the red box in g
-    """
-    transformer = PDFNetCoordinateTransformer()
-
-    assert transformer.forward(position_metadata_in_reference_system) == position_metadata_in_given_system
-
-    assert transformer.backward(position_metadata_in_given_system) == position_metadata_in_reference_system
-
-    assert (
-        compose(transformer.backward, transformer.forward)(position_metadata_in_reference_system)
-        == position_metadata_in_reference_system
-    )