diff --git a/.gitignore b/.gitignore
index d931831..66d66bc 100644
--- a/.gitignore
+++ b/.gitignore
@@ -25,6 +25,7 @@ dmypy.json
 
 # User-specific stuff
 .idea
+.*.swp
 
 # Build artifacts
 /build
diff --git a/src/dinglehopper/line_dirs_test/basic/gt/a.gt.txt b/src/dinglehopper/tests/data/line_dirs/basic/gt/a.gt.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/basic/gt/a.gt.txt
rename to src/dinglehopper/tests/data/line_dirs/basic/gt/a.gt.txt
diff --git a/src/dinglehopper/line_dirs_test/basic/gt/b.gt.txt b/src/dinglehopper/tests/data/line_dirs/basic/gt/b.gt.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/basic/gt/b.gt.txt
rename to src/dinglehopper/tests/data/line_dirs/basic/gt/b.gt.txt
diff --git a/src/dinglehopper/line_dirs_test/basic/ocr/a.some-ocr.txt b/src/dinglehopper/tests/data/line_dirs/basic/ocr/a.some-ocr.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/basic/ocr/a.some-ocr.txt
rename to src/dinglehopper/tests/data/line_dirs/basic/ocr/a.some-ocr.txt
diff --git a/src/dinglehopper/line_dirs_test/basic/ocr/b.some-ocr.txt b/src/dinglehopper/tests/data/line_dirs/basic/ocr/b.some-ocr.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/basic/ocr/b.some-ocr.txt
rename to src/dinglehopper/tests/data/line_dirs/basic/ocr/b.some-ocr.txt
diff --git a/src/dinglehopper/line_dirs_test/merged/a/a.dummy.jpg b/src/dinglehopper/tests/data/line_dirs/merged/a/a.dummy.jpg
similarity index 100%
rename from src/dinglehopper/line_dirs_test/merged/a/a.dummy.jpg
rename to src/dinglehopper/tests/data/line_dirs/merged/a/a.dummy.jpg
diff --git a/src/dinglehopper/line_dirs_test/merged/a/a.gt.txt b/src/dinglehopper/tests/data/line_dirs/merged/a/a.gt.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/merged/a/a.gt.txt
rename to src/dinglehopper/tests/data/line_dirs/merged/a/a.gt.txt
diff --git a/src/dinglehopper/line_dirs_test/merged/a/a.some-ocr.txt b/src/dinglehopper/tests/data/line_dirs/merged/a/a.some-ocr.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/merged/a/a.some-ocr.txt
rename to src/dinglehopper/tests/data/line_dirs/merged/a/a.some-ocr.txt
diff --git a/src/dinglehopper/line_dirs_test/merged/b/b.dummy.jpg b/src/dinglehopper/tests/data/line_dirs/merged/b/b.dummy.jpg
similarity index 100%
rename from src/dinglehopper/line_dirs_test/merged/b/b.dummy.jpg
rename to src/dinglehopper/tests/data/line_dirs/merged/b/b.dummy.jpg
diff --git a/src/dinglehopper/line_dirs_test/merged/b/b.gt.txt b/src/dinglehopper/tests/data/line_dirs/merged/b/b.gt.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/merged/b/b.gt.txt
rename to src/dinglehopper/tests/data/line_dirs/merged/b/b.gt.txt
diff --git a/src/dinglehopper/line_dirs_test/merged/b/b.some-ocr.txt b/src/dinglehopper/tests/data/line_dirs/merged/b/b.some-ocr.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/merged/b/b.some-ocr.txt
rename to src/dinglehopper/tests/data/line_dirs/merged/b/b.some-ocr.txt
diff --git a/src/dinglehopper/line_dirs_test/subdirs/gt/a/a.gt.txt b/src/dinglehopper/tests/data/line_dirs/subdirs/gt/a/a.gt.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/subdirs/gt/a/a.gt.txt
rename to src/dinglehopper/tests/data/line_dirs/subdirs/gt/a/a.gt.txt
diff --git a/src/dinglehopper/line_dirs_test/subdirs/gt/b/b.gt.txt b/src/dinglehopper/tests/data/line_dirs/subdirs/gt/b/b.gt.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/subdirs/gt/b/b.gt.txt
rename to src/dinglehopper/tests/data/line_dirs/subdirs/gt/b/b.gt.txt
diff --git a/src/dinglehopper/line_dirs_test/subdirs/ocr/a/a.some-ocr.txt b/src/dinglehopper/tests/data/line_dirs/subdirs/ocr/a/a.some-ocr.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/subdirs/ocr/a/a.some-ocr.txt
rename to src/dinglehopper/tests/data/line_dirs/subdirs/ocr/a/a.some-ocr.txt
diff --git a/src/dinglehopper/line_dirs_test/subdirs/ocr/b/b.some-ocr.txt b/src/dinglehopper/tests/data/line_dirs/subdirs/ocr/b/b.some-ocr.txt
similarity index 100%
rename from src/dinglehopper/line_dirs_test/subdirs/ocr/b/b.some-ocr.txt
rename to src/dinglehopper/tests/data/line_dirs/subdirs/ocr/b/b.some-ocr.txt
diff --git a/src/dinglehopper/line_dirs_test.py b/src/dinglehopper/tests/test_line_dirs.py
similarity index 52%
rename from src/dinglehopper/line_dirs_test.py
rename to src/dinglehopper/tests/test_line_dirs.py
index 9827f01..03966e1 100644
--- a/src/dinglehopper/line_dirs_test.py
+++ b/src/dinglehopper/tests/test_line_dirs.py
@@ -1,29 +1,30 @@
-import os.path
-import itertools
-from typing import Iterator, Tuple
+import os
 
+from ..cli_line_dirs import find_gt_and_ocr_files, find_gt_and_ocr_files_autodetect
 
+data_dir = os.path.join(os.path.dirname(os.path.abspath(__file__)), "data")
 
 
 def test_basic():
     """Test the dumb method: User gives directories and suffixes."""
     pairs = list(
         find_gt_and_ocr_files(
-            "line_dirs_test/basic/gt",
+            os.path.join(data_dir, "line_dirs/basic/gt"),
             ".gt.txt",
-            "line_dirs_test/basic/ocr",
+            os.path.join(data_dir, "line_dirs/basic/ocr"),
             ".some-ocr.txt",
         )
     )
 
     assert len(pairs) == 2
 
+
 def test_basic_autodetect():
-    """Test the autodetect method: User gives directories, suffixes are autodetected if possible"""
+    """Test autodetect: User gives directories, suffixes are autodetected if possible"""
     pairs = list(
         find_gt_and_ocr_files_autodetect(
-            "line_dirs_test/basic/gt",
-            "line_dirs_test/basic/ocr",
+            os.path.join(data_dir, "line_dirs/basic/gt"),
+            os.path.join(data_dir, "line_dirs/basic/ocr"),
         )
     )
 
@@ -34,9 +35,9 @@ def test_subdirs():
     """Test the dumb method: Should also work when subdirectories are involved."""
     pairs = list(
         find_gt_and_ocr_files(
-            "line_dirs_test/subdirs/gt",
+            os.path.join(data_dir, "line_dirs/subdirs/gt"),
             ".gt.txt",
-            "line_dirs_test/subdirs/ocr",
+            os.path.join(data_dir, "line_dirs/subdirs/ocr"),
             ".some-ocr.txt",
         )
     )
@@ -48,30 +49,23 @@ def test_subdirs_autodetect():
     """Test the autodetect method: Should also work when subdirectories are involved."""
     pairs = list(
         find_gt_and_ocr_files_autodetect(
-            "line_dirs_test/subdirs/gt",
-            "line_dirs_test/subdirs/ocr",
+            os.path.join(data_dir, "line_dirs/subdirs/gt"),
+            os.path.join(data_dir, "line_dirs/subdirs/ocr"),
         )
     )
 
     assert len(pairs) == 2
 
+
 def test_merged():
-    """Test the dumb method: Should also work when GT and OCR texts are in the same directories."""
+    """Test the dumb method: GT and OCR texts are in the same directories."""
     pairs = list(
         find_gt_and_ocr_files(
-            "line_dirs_test/merged",
+            os.path.join(data_dir, "line_dirs/merged"),
             ".gt.txt",
-            "line_dirs_test/merged",
+            os.path.join(data_dir, "line_dirs/merged"),
             ".some-ocr.txt",
         )
     )
 
     assert len(pairs) == 2
-
-if __name__ == "__main__":
-    test_basic()
-    test_subdirs()
-    test_merged()
-
-    test_basic_autodetect()
-    test_subdirs_autodetect()