chore: example test of creating a custom transformer

Author: ringoldsdev

tests/test_custom_transformer.py

@@ -0,0 +1,30 @@
+from collections.abc import Iterable
+from collections.abc import Iterator
+
+from laygo.context.types import IContextManager
+from laygo.pipeline import Pipeline
+from laygo.transformers.types import BaseTransformer
+
+# In should be an int
+
+
+class MultiplierTransformer(BaseTransformer[int, int]):
+  def __call__(self, data: Iterable[int], context: IContextManager | None = None) -> Iterator[int]:
+    """
+    Takes an iterable of data and yields each item multiplied.
+    """
+
+    multiplier = context["multiplier"] if context and "multiplier" in context else 1
+
+    for item in data:
+      yield item * multiplier
+
+
+class TestCustomTransformer:
+  def test_multiplier_transformer(self):
+    data = [1, 2, 3, 4, 5]
+    expected_output = [2, 4, 6, 8, 10]
+
+    result, _ = Pipeline(data).context({"multiplier": 2}).apply(MultiplierTransformer()).to_list()
+
+    assert result == expected_output, f"Expected {expected_output}, but got {result}"