diff --git a/tests/conftest.py b/tests/conftest.py
index a216a94..bedcebf 100644
--- a/tests/conftest.py
+++ b/tests/conftest.py
@@ -3,6 +3,7 @@ from typing import Dict, List
 
 import pytest
 from recon.corpus import Corpus
+from recon.dataset import Dataset
 from recon.loaders import read_jsonl
 from recon.preprocess import SpacyPreProcessor
 from recon.recognizer import SpacyEntityRecognizer
@@ -31,7 +32,7 @@ def test_texts():
 @pytest.fixture()
 def example_data() -> Dict[str, List[Example]]:
     """Fixture to load example train/dev/test data that has inconsistencies.
-    
+
     Returns:
         Dict[str, List[Example]]: Dataset containing the train/dev/test split
     """
@@ -46,7 +47,7 @@ def example_data() -> Dict[str, List[Example]]:
 @pytest.fixture()
 def example_corpus() -> Corpus:
     """Fixture to load example train/dev/test data that has inconsistencies.
-    
+
     Returns:
         Corpus: Example data
     """
@@ -57,7 +58,7 @@ def example_corpus() -> Corpus:
 @pytest.fixture()
 def example_corpus_processed() -> Corpus:
     """Fixture to load example train/dev/test data that has inconsistencies.
-    
+
     Returns:
         Corpus: Example data
     """
diff --git a/tests/test_operations.py b/tests/test_operations.py
index 8c14c1f..e167e2b 100644
--- a/tests/test_operations.py
+++ b/tests/test_operations.py
@@ -1,4 +1,23 @@
+import pytest
+from recon.dataset import Dataset
 from recon.operations import Operation, operation, registry
+from recon.types import Example, Span
+
+
+@pytest.fixture()
+def ds():
+    ds = Dataset(
+        name="test",
+        data=[
+            Example(
+                text="this is a test example with something else",
+                spans=[Span(text="something", start=28, end=37, label="TEST_ENTITY")],
+            )
+        ],
+    )
+    ds.apply_("recon.v1.add_tokens")
+
+    return ds
 
 
 def test_operation_init():
@@ -8,3 +27,67 @@ def test_operation_init():
 
     assert "test_operation" in registry.operations
     assert isinstance(registry.operations.get("test_operation"), Operation)
+
+
+def test_change_operation(ds):
+    @operation("change_annotation")
+    def operation_test(example):
+        example.spans[0].text = "something else"
+        example.spans[0].end = 42
+
+        return example
+
+    assert "change_annotation" in registry.operations
+    assert isinstance(registry.operations.get("change_annotation"), Operation)
+
+    assert len(ds.operations) == 1
+    ds.apply_("change_annotation")
+    assert len(ds.operations) == 2
+
+    assert ds.operations[1].name == "change_annotation"
+    assert len(ds.example_store) == 3
+
+    assert len(ds) == 1
+
+
+def test_add_operation(ds):
+    @operation("add_and_change_example")
+    def operation_test(example):
+        new_example = Example(text="this is a test", spans=[])
+
+        example.spans[0].text = "something else"
+        example.spans[0].end = 42
+
+        return [new_example, example]
+
+    assert "add_and_change_example" in registry.operations
+    assert isinstance(registry.operations.get("add_and_change_example"), Operation)
+
+    assert len(ds.operations) == 1
+    ds.apply_("add_and_change_example")
+    assert len(ds.operations) == 2
+
+    assert ds.operations[1].name == "add_and_change_example"
+    assert len(ds.example_store) == 4
+
+    assert len(ds) == 2
+
+
+def test_remove_operation(ds):
+    @operation("remove_example")
+    def operation_test(example):
+        return None
+
+    assert "remove_example" in registry.operations
+    assert isinstance(registry.operations.get("remove_example"), Operation)
+
+    assert len(ds.operations) == 1
+    ds.apply_("remove_example")
+    assert len(ds.operations) == 2
+
+    assert ds.operations[1].name == "remove_example"
+    assert len(ds.example_store) == 2
+
+    assert len(ds) == 0
+
+    print(ds.example_store._map)