feat: Make PipelineBase().validate_input public (#9520)

* Make validate_input public

* Add reno

Author: sjrl

haystack/core/pipeline/async_pipeline.py

@@ -198,7 +198,7 @@ async def process_results():
         prepared_data = self._prepare_component_input_data(data)
 
         # raises ValueError if input is malformed in some way
-        self._validate_input(prepared_data)
+        self.validate_input(prepared_data)
         inputs_state = self._convert_to_internal_format(prepared_data)
 
         # For quick lookup of downstream receivers

haystack/core/pipeline/base.py

@@ -899,7 +899,7 @@ def _create_component_span(
             parent_span=parent_span,
         )
 
-    def _validate_input(self, data: Dict[str, Any]) -> None:
+    def validate_input(self, data: Dict[str, Any]) -> None:
         """
         Validates pipeline input data.
 

haystack/core/pipeline/pipeline.py

@@ -172,7 +172,7 @@ def run(  # noqa: PLR0915, PLR0912
         data = self._prepare_component_input_data(data)
 
         # Raise ValueError if input is malformed in some way
-        self._validate_input(data)
+        self.validate_input(data)
 
         if include_outputs_from is None:
             include_outputs_from = set()

releasenotes/notes/make-validate-input-public-e547ef5b75069bd7.yaml

@@ -0,0 +1,6 @@
+---
+enhancements:
+  - |
+    Make the PipelineBase().validate_input method public so users can use it with the confidence that it won't receive breaking changes without warning.
+    This method is useful for checking that all required connections in a pipeline have a connection and is automatically called in the run method of Pipeline.
+    It is being exposed as public for users who would like to call this method before runtime to validate the pipeline.