test: make tests independent of working directory (#67)

Closes #57.

### Summary of Changes

`pytest` can now be launched in any subdirectory of the `tests` folder
and tests still work. When we access test data in the `tests/resources`
folder, we should now always use the new function
`resolve_resource_path` to get an absolute path to a resource, which is
thus independent of the working directory.

---------

Co-authored-by: lars-reimann <[email protected]>

Author: lars-reimann

tests/fixtures/__init__.py

@@ -0,0 +1 @@
+from ._resources import resolve_resource_path

tests/fixtures/_resources.py

@@ -0,0 +1,21 @@
+import os
+
+_resources_root = os.path.join(os.path.dirname(__file__), "..", "resources")
+
+
+def resolve_resource_path(resource_path: str) -> str:
+    """
+    Resolves a path relative to the `resources` directory to an absolute path.
+
+    Parameters
+    ----------
+    resource_path : str
+        The path to the resource relative to the `resources` directory.
+
+    Returns
+    -------
+    absolute_path : str
+        The absolute path to the resource.
+    """
+
+    return os.path.join(_resources_root, resource_path)

tests/safeds/data/tabular/containers/_row/test_has_column.py

@@ -1,13 +1,14 @@
 from safeds.data.tabular.containers import Table
+from tests.fixtures import resolve_resource_path
 
 
 def test_has_column_positive() -> None:
-    table = Table.from_csv("tests/resources/test_table_has_column.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_has_column.csv"))
     row = table.to_rows()[0]
     assert row.has_column("A")
 
 
 def test_has_column_negative() -> None:
-    table = Table.from_csv("tests/resources/test_table_has_column.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_has_column.csv"))
     row = table.to_rows()[0]
     assert not row.has_column("C")

tests/safeds/data/tabular/containers/_table/test_column_drop.py

@@ -1,17 +1,18 @@
 import pytest
 from safeds.data.tabular.containers import Table
 from safeds.exceptions import UnknownColumnNameError
+from tests.fixtures import resolve_resource_path
 
 
 def test_table_column_drop() -> None:
-    table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     transformed_table = table.drop_columns(["A"])
     assert transformed_table.schema.has_column(
         "B"
     ) and not transformed_table.schema.has_column("A")
 
 
 def test_table_column_drop_warning() -> None:
-    table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     with pytest.raises(UnknownColumnNameError):
         table.drop_columns(["C"])

tests/safeds/data/tabular/containers/_table/test_column_keep.py

@@ -1,17 +1,18 @@
 import pytest
 from safeds.data.tabular.containers import Table
 from safeds.exceptions import UnknownColumnNameError
+from tests.fixtures import resolve_resource_path
 
 
 def test_table_column_keep() -> None:
-    table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     transformed_table = table.keep_columns(["A"])
     assert transformed_table.schema.has_column(
         "A"
     ) and not transformed_table.schema.has_column("B")
 
 
 def test_table_column_keep_warning() -> None:
-    table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     with pytest.raises(UnknownColumnNameError):
         table.keep_columns(["C"])

tests/safeds/data/tabular/containers/_table/test_drop_duplicate_rows.py

@@ -1,17 +1,18 @@
 import pandas as pd
 import pytest
 from safeds.data.tabular.containers import Table
+from tests.fixtures import resolve_resource_path
 
 
 @pytest.mark.parametrize(
     "path",
     [
-        "tests/resources/test_table_duplicate_rows_duplicates.csv",
-        "tests/resources/test_table_duplicate_rows_no_duplicates.csv",
+        "test_table_duplicate_rows_duplicates.csv",
+        "test_table_duplicate_rows_no_duplicates.csv",
     ],
 )
 def test_drop_duplicate_rows(path: str) -> None:
     expected_table = Table(pd.DataFrame(data={"A": [1, 4], "B": [2, 5]}))
-    table = Table.from_csv(path)
+    table = Table.from_csv(resolve_resource_path(path))
     result_table = table.drop_duplicate_rows()
     assert expected_table == result_table

tests/safeds/data/tabular/containers/_table/test_from_columns.py

@@ -2,10 +2,11 @@
 import pytest
 from safeds.data.tabular.containers import Column, Table
 from safeds.exceptions import MissingDataError
+from tests.fixtures import resolve_resource_path
 
 
 def test_from_columns() -> None:
-    table_expected = Table.from_csv("tests/resources/test_column_table.csv")
+    table_expected = Table.from_csv(resolve_resource_path("test_column_table.csv"))
     columns_table: list[Column] = [
         Column(pd.Series([1, 4]), "A"),
         Column(pd.Series([2, 5]), "B"),

tests/safeds/data/tabular/containers/_table/test_from_rows.py

@@ -1,10 +1,11 @@
 import pytest
 from safeds.data.tabular.containers import Row, Table
 from safeds.exceptions import MissingDataError
+from tests.fixtures import resolve_resource_path
 
 
 def test_from_rows() -> None:
-    table_expected = Table.from_csv("tests/resources/test_row_table.csv")
+    table_expected = Table.from_csv(resolve_resource_path("test_row_table.csv"))
     rows_is: list[Row] = table_expected.to_rows()
     table_is: Table = Table.from_rows(rows_is)
 

tests/safeds/data/tabular/containers/_table/test_get_row.py

@@ -1,21 +1,22 @@
 import pytest
 from safeds.data.tabular.containers import Table
 from safeds.exceptions import IndexOutOfBoundsError
+from tests.fixtures import resolve_resource_path
 
 
 def test_get_row() -> None:
-    table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     val = table.get_row(0)
     assert val.get_value("A") == 1 and val.get_value("B") == 2
 
 
 def test_get_row_negative_index() -> None:
-    table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     with pytest.raises(IndexOutOfBoundsError):
         table.get_row(-1)
 
 
 def test_get_row_out_of_bounds_index() -> None:
-    table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     with pytest.raises(IndexOutOfBoundsError):
         table.get_row(5)

tests/safeds/data/tabular/containers/_table/test_has_column.py

@@ -1,11 +1,12 @@
 from safeds.data.tabular.containers import Table
+from tests.fixtures import resolve_resource_path
 
 
 def test_has_column_positive() -> None:
-    table = Table.from_csv("tests/resources/test_table_has_column.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_has_column.csv"))
     assert table.has_column("A")
 
 
 def test_has_column_negative() -> None:
-    table = Table.from_csv("tests/resources/test_table_has_column.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_has_column.csv"))
     assert not table.has_column("C")

tests/safeds/data/tabular/containers/_table/test_read_csv.py

@@ -1,9 +1,10 @@
 import pytest
 from safeds.data.tabular.containers import Table
+from tests.fixtures import resolve_resource_path
 
 
 def test_read_csv_valid() -> None:
-    table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     assert (
         table.get_column("A").get_value(0) == 1
         and table.get_column("B").get_value(0) == 2
@@ -12,4 +13,4 @@ def test_read_csv_valid() -> None:
 
 def test_read_csv_invalid() -> None:
     with pytest.raises(FileNotFoundError):
-        Table.from_csv("tests/resources/test_table_read_csv_invalid.csv")
+        Table.from_csv(resolve_resource_path("test_table_read_csv_invalid.csv"))

tests/safeds/data/tabular/containers/_table/test_read_json.py

@@ -1,9 +1,10 @@
 import pytest
 from safeds.data.tabular.containers import Table
+from tests.fixtures import resolve_resource_path
 
 
 def test_read_json_valid() -> None:
-    table = Table.from_json("tests/resources/test_table_read_json.json")
+    table = Table.from_json(resolve_resource_path("test_table_read_json.json"))
     assert (
         table.get_column("A").get_value(0) == 1
         and table.get_column("B").get_value(0) == 2
@@ -12,4 +13,4 @@ def test_read_json_valid() -> None:
 
 def test_read_json_invalid() -> None:
     with pytest.raises(FileNotFoundError):
-        Table.from_json("tests/resources/test_table_read_json_invalid.json")
+        Table.from_json(resolve_resource_path("test_table_read_json_invalid.json"))

tests/safeds/data/tabular/containers/_table/test_rename.py

@@ -1,6 +1,7 @@
 import pytest
 from safeds.data.tabular.containers import Table
 from safeds.exceptions import DuplicateColumnNameError, UnknownColumnNameError
+from tests.fixtures import resolve_resource_path
 
 
 @pytest.mark.parametrize(
@@ -10,7 +11,7 @@
 def test_rename_valid(
     name_from: str, name_to: str, column_one: str, column_two: str
 ) -> None:
-    table: Table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table: Table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     renamed_table = table.rename_column(name_from, name_to)
     assert renamed_table.schema.has_column(column_one)
     assert renamed_table.schema.has_column(column_two)
@@ -26,6 +27,6 @@ def test_rename_valid(
     ],
 )
 def test_rename_invalid(name_from: str, name_to: str, error: Exception) -> None:
-    table: Table = Table.from_csv("tests/resources/test_table_read_csv.csv")
+    table: Table = Table.from_csv(resolve_resource_path("test_table_read_csv.csv"))
     with pytest.raises(error):
         table.rename_column(name_from, name_to)

tests/safeds/data/tabular/containers/_table/test_replace_column.py

@@ -6,20 +6,21 @@
     DuplicateColumnNameError,
     UnknownColumnNameError,
 )
+from tests.fixtures import resolve_resource_path
 
 
 @pytest.mark.parametrize(
     "column_name, path",
     [
-        ("C", "tests/resources/test_table_replace_column_output_different_name.csv"),
-        ("D", "tests/resources/test_table_replace_column_output_same_name.csv"),
+        ("C", "test_table_replace_column_output_different_name.csv"),
+        ("D", "test_table_replace_column_output_same_name.csv"),
     ],
 )
 def test_replace_valid(column_name: str, path: str) -> None:
     input_table: Table = Table.from_csv(
-        "tests/resources/test_table_replace_column_input.csv"
+        resolve_resource_path("test_table_replace_column_input.csv")
     )
-    expected: Table = Table.from_csv(path)
+    expected: Table = Table.from_csv(resolve_resource_path(path))
 
     column = Column(pd.Series(["d", "e", "f"]), column_name)
 
@@ -43,7 +44,7 @@ def test_replace_invalid(
     error: type[Exception],
 ) -> None:
     input_table: Table = Table.from_csv(
-        "tests/resources/test_table_replace_column_input.csv"
+        resolve_resource_path("test_table_replace_column_input.csv")
     )
     column = Column(pd.Series(column_values), column_name)
 

tests/safeds/data/tabular/containers/_table/test_table_add_column.py

@@ -2,13 +2,16 @@
 import pytest
 from safeds.data.tabular.containers import Column, Table
 from safeds.exceptions import ColumnSizeError, DuplicateColumnNameError
+from tests.fixtures import resolve_resource_path
 
 
 def test_table_add_column_valid() -> None:
     input_table = Table.from_csv(
-        "tests/resources/test_table_add_column_valid_input.csv"
+        resolve_resource_path("test_table_add_column_valid_input.csv")
+    )
+    expected = Table.from_csv(
+        resolve_resource_path("test_table_add_column_valid_output.csv")
     )
-    expected = Table.from_csv("tests/resources/test_table_add_column_valid_output.csv")
     column = Column(pd.Series(["a", "b", "c"]), "C")
 
     result = input_table.add_column(column)
@@ -26,7 +29,7 @@ def test_table_add_column_(
     column_values: list[str], column_name: str, error: type[Exception]
 ) -> None:
     input_table = Table.from_csv(
-        "tests/resources/test_table_add_column_valid_input.csv"
+        resolve_resource_path("test_table_add_column_valid_input.csv")
     )
     column = Column(pd.Series(column_values), column_name)
 

tests/safeds/data/tabular/containers/_table/test_to_columns.py

@@ -1,14 +1,15 @@
 import pandas as pd
 import pytest
 from safeds.data.tabular.containers import Column, Table
+from tests.fixtures import resolve_resource_path
 
 
 @pytest.mark.parametrize(
     "values, name, index",
     [([1, 4], "A", 0), ([2, 5], "B", 1)],
 )
 def test_to_columns(values: list[int], name: str, index: int) -> None:
-    table = Table.from_csv("tests/resources/test_column_table.csv")
+    table = Table.from_csv(resolve_resource_path("test_column_table.csv"))
     columns_list: list[Column] = table.to_columns()
 
     column_expected: Column = Column(pd.Series(values, name=name), name)

tests/safeds/data/tabular/containers/_table/test_to_rows.py

@@ -1,10 +1,11 @@
 import pandas as pd
 from safeds.data.tabular.containers import Row, Table
 from safeds.data.tabular.typing import IntColumnType, StringColumnType, TableSchema
+from tests.fixtures import resolve_resource_path
 
 
 def test_to_rows() -> None:
-    table = Table.from_csv("tests/resources/test_row_table.csv")
+    table = Table.from_csv(resolve_resource_path("test_row_table.csv"))
     expected_schema: TableSchema = TableSchema(
         {
             "A": IntColumnType(),

tests/safeds/data/tabular/containers/_table/test_transform_column.py

@@ -1,25 +1,26 @@
 import pytest
 from safeds.data.tabular.containers import Table
 from safeds.exceptions import UnknownColumnNameError
+from tests.fixtures import resolve_resource_path
 
 
 def test_transform_column_valid() -> None:
     input_table: Table = Table.from_csv(
-        "tests/resources/test_table_transform_column.csv"
+        resolve_resource_path("test_table_transform_column.csv")
     )
 
     result: Table = input_table.transform_column(
         "A", lambda row: row.get_value("A") * 2
     )
 
     assert result == Table.from_csv(
-        "tests/resources/test_table_transform_column_output.csv"
+        resolve_resource_path("test_table_transform_column_output.csv")
     )
 
 
 def test_transform_column_invalid() -> None:
     input_table: Table = Table.from_csv(
-        "tests/resources/test_table_transform_column.csv"
+        resolve_resource_path("test_table_transform_column.csv")
     )
 
     with pytest.raises(UnknownColumnNameError):

tests/safeds/data/tabular/containers/_tagged_table/test_feature_vectors.py

@@ -1,8 +1,9 @@
 from safeds.data.tabular.containers import Table, TaggedTable
+from tests.fixtures import resolve_resource_path
 
 
 def test_tagged_table_feature_vectors() -> None:
-    table = Table.from_csv("tests/resources/test_tagged_table.csv")
+    table = Table.from_csv(resolve_resource_path("test_tagged_table.csv"))
     tagged_table = TaggedTable(table, "T")
     assert "T" not in tagged_table.feature_vectors._data
     assert tagged_table.feature_vectors.schema.has_column("A")

tests/safeds/data/tabular/containers/_tagged_table/test_target_values.py

@@ -1,8 +1,9 @@
 from safeds.data.tabular.containers import Table, TaggedTable
+from tests.fixtures import resolve_resource_path
 
 
 def test_tagged_table_target_values() -> None:
-    table = Table.from_csv("tests/resources/test_tagged_table.csv")
+    table = Table.from_csv(resolve_resource_path("test_tagged_table.csv"))
     tagged_table = TaggedTable(table, "T")
     assert tagged_table.target_values._data[0] == 0
     assert tagged_table.target_values._data[1] == 1

tests/safeds/data/tabular/typing/_table_schema/test_get_column_type.py

@@ -1,9 +1,10 @@
 import numpy as np
 from safeds.data.tabular.containers import Table
 from safeds.data.tabular.typing import ColumnType
+from tests.fixtures import resolve_resource_path
 
 
 def test_get_type_of_column() -> None:
-    table = Table.from_json("tests/resources/test_schema_table.json")
+    table = Table.from_json(resolve_resource_path("test_schema_table.json"))
     table_column_type = table.schema.get_type_of_column("A")
     assert table_column_type == ColumnType.from_numpy_dtype(np.dtype("int64"))