fix: Cherry-pick upstream changes from deepset-ai/haystack#8572

haystack_experimental/components/builders/chat_prompt_builder.py

@@ -3,7 +3,7 @@
 # SPDX-License-Identifier: Apache-2.0
 
 from copy import deepcopy
-from typing import Any, Dict, List, Optional, Set
+from typing import Any, Dict, List, Literal, Optional, Set, Union
 
 from haystack import component, default_from_dict, default_to_dict, logging
 from jinja2 import meta
@@ -104,7 +104,7 @@ class ChatPromptBuilder:
     def __init__(
         self,
         template: Optional[List[ChatMessage]] = None,
-        required_variables: Optional[List[str]] = None,
+        required_variables: Optional[Union[List[str], Literal["*"]]] = None,
         variables: Optional[List[str]] = None,
     ):
         """
@@ -116,7 +116,8 @@ def __init__(
             the `init` method` or the `run` method.
         :param required_variables:
             List variables that must be provided as input to ChatPromptBuilder.
-            If a variable listed as required is not provided, an exception is raised. Optional.
+            If a variable listed as required is not provided, an exception is raised.
+            If set to "*", all variables found in the prompt are required.
         :param variables:
             List input variables to use in prompt templates instead of the ones inferred from the
             `template` parameter. For example, to use more variables during prompt engineering than the ones present
@@ -131,7 +132,7 @@ def __init__(
         if template and not variables:
             for message in template:
                 if message.is_from(ChatRole.USER) or message.is_from(ChatRole.SYSTEM):
-                    # infere variables from template
+                    # infer variables from template
                     if message.text is None:
                         raise ValueError(
                             f"The {self.__class__.__name__} requires a non-empty list of ChatMessage"
@@ -140,10 +141,11 @@ def __init__(
                     ast = self._env.parse(message.text)
                     template_variables = meta.find_undeclared_variables(ast)
                     variables += list(template_variables)
+        self.variables = variables
 
         # setup inputs
-        for var in variables:
-            if var in self.required_variables:
+        for var in self.variables:
+            if self.required_variables == "*" or var in self.required_variables:
                 component.set_input_type(self, var, Any)
             else:
                 component.set_input_type(self, var, Any, "")
@@ -224,12 +226,16 @@ def _validate_variables(self, provided_variables: Set[str]):
         :raises ValueError:
             If no template is provided or if all the required template variables are not provided.
         """
-        missing_variables = [var for var in self.required_variables if var not in provided_variables]
+        if self.required_variables == "*":
+            required_variables = sorted(self.variables)
+        else:
+            required_variables = self.required_variables
+        missing_variables = [var for var in required_variables if var not in provided_variables]
         if missing_variables:
             missing_vars_str = ", ".join(missing_variables)
             raise ValueError(
                 f"Missing required input variables in ChatPromptBuilder: {missing_vars_str}. "
-                f"Required variables: {self.required_variables}. Provided variables: {provided_variables}."
+                f"Required variables: {required_variables}. Provided variables: {provided_variables}."
             )
 
     def to_dict(self) -> Dict[str, Any]:

test/components/builders/test_chat_prompt_builder.py

@@ -140,6 +140,18 @@ def test_run_template_variable_overrides_variable(self):
             "prompt": [ChatMessage.from_user("This is a test_from_template_var")]
         }
 
+    def test_run_with_missing_required_input_using_star(self):
+        builder = ChatPromptBuilder(
+            template=[ChatMessage.from_user("This is a {{ foo }}, not a {{ bar }}")],
+            required_variables="*",
+        )
+        with pytest.raises(ValueError, match="foo"):
+            builder.run(bar="bar")
+        with pytest.raises(ValueError, match="bar"):
+            builder.run(foo="foo")
+        with pytest.raises(ValueError, match="bar, foo"):
+            builder.run()
+
     def test_run_without_input(self):
         builder = ChatPromptBuilder(
             template=[ChatMessage.from_user("This is a template without input")]