x

libs/langchain/langchain/schema/runnable/utils.py

@@ -107,6 +107,14 @@ def get_function_first_arg_dict_keys(func: Callable) -> Optional[List[str]]:
 
 
 def get_lambda_source(func: Callable) -> Optional[str]:
+    """Get the source code of a lambda function.
+
+    Args:
+        func: a callable that can be a lambda function
+
+    Returns:
+        str: the source code of the lambda function
+    """
     try:
         code = inspect.getsource(func)
         tree = ast.parse(textwrap.dedent(code))
@@ -118,6 +126,15 @@ def get_lambda_source(func: Callable) -> Optional[str]:
 
 
 def indent_lines_after_first(text: str, prefix: str) -> str:
+    """Indent all lines of text after the first line.
+
+    Args:
+        text:  The text to indent
+        prefix: Used to determine the number of spaces to indent
+
+    Returns:
+        str: The indented text
+    """
     n_spaces = len(prefix)
     spaces = " " * n_spaces
     lines = text.splitlines()

libs/langchain/tests/unit_tests/schema/runnable/test_runnable.py

@@ -2739,3 +2739,34 @@ async def test_runnable_branch_abatch() -> None:
     )
 
     assert await branch.abatch([1, 10, 0]) == [2, 100, -1]
+
+
+def test_reprsentation_of_runnables() -> None:
+    """Test representation of runnables."""
+    runnable = RunnableLambda(lambda x: x * 2)
+    assert repr(runnable) == "RunnableLambda(lambda x: x * 2)"
+
+    def f(x: int) -> int:
+        """Return 2."""
+        return 2
+
+    assert repr(RunnableLambda(func=f)) == "RunnableLambda(...)"
+
+    async def af(x: int) -> int:
+        """Return 2."""
+        return 2
+
+    assert repr(RunnableLambda(func=f, afunc=af)) == "RunnableLambda(...)"
+
+    sequence = RunnableLambda(lambda x: x + 2) | {
+        "a": RunnableLambda(lambda x: x * 2),
+        "b": RunnableLambda(lambda x: x * 3),
+    }
+
+    assert repr(sequence) == (
+        "RunnableLambda(lambda x: x * 3)\n"
+        "| {\n"
+        "    a: RunnableLambda(...),\n"
+        "    b: RunnableLambda(...)\n"
+        "  }"
+    )

libs/langchain/tests/unit_tests/schema/runnable/test_utils.py

@@ -0,0 +1,34 @@
+import pytest
+
+from langchain.schema.runnable.utils import (
+    get_lambda_source,
+    indent_lines_after_first,
+)
+from langchain.schema.runnable.base import RunnableLambda
+
+
+# Test get_lambda_source function
+@pytest.mark.parametrize(
+    "func, expected_source",
+    [
+        (lambda x: x * 2, "lambda x: x * 2"),
+        (lambda a, b: a + b, "lambda a, b: a + b"),
+        (lambda x: x if x > 0 else 0, "lambda x: x if x > 0 else 0"),
+    ],
+)
+def test_get_lambda_source(func, expected_source):
+    source = get_lambda_source(func)
+    assert source == expected_source
+
+
+
+@pytest.mark.parametrize(
+    "text,prefix,expected_output",
+    [
+        ("line 1\nline 2\nline 3", "1", "line 1\n line 2\n line 3"),
+        ("line 1\nline 2\nline 3", "ax", "line 1\n  line 2\n  line 3"),
+    ],
+)
+def test_indent_lines_after_first(text, prefix, expected_output):
+    indented_text = indent_lines_after_first(text, prefix)
+    assert indented_text == expected_output