Include "no escape" and "inverted section" mustache vars in Prompt.input_variables and Prompt.input_schema (#22981)

libs/core/tests/unit_tests/prompts/test_prompt.py

@@ -67,7 +67,7 @@ def test_mustache_prompt_from_template() -> None:
     }
 
     # Multiple input variables with repeats.
-    template = "This {{bar}} is a {{foo}} test {{foo}}."
+    template = "This {{bar}} is a {{foo}} test {{&foo}}."
     prompt = PromptTemplate.from_template(template, template_format="mustache")
     assert prompt.format(bar="baz", foo="bar") == "This baz is a bar test bar."
     assert prompt.input_variables == ["bar", "foo"]
@@ -81,7 +81,7 @@ def test_mustache_prompt_from_template() -> None:
     }
 
     # Nested variables.
-    template = "This {{obj.bar}} is a {{obj.foo}} test {{foo}}."
+    template = "This {{obj.bar}} is a {{obj.foo}} test {{{foo}}}."
     prompt = PromptTemplate.from_template(template, template_format="mustache")
     assert prompt.format(obj={"bar": "foo", "foo": "bar"}, foo="baz") == (
         "This foo is a bar test baz."
@@ -167,6 +167,22 @@ def test_mustache_prompt_from_template() -> None:
         },
     }
 
+    template = """This{{^foo}}
+        no foos
+    {{/foo}}is a test."""
+    prompt = PromptTemplate.from_template(template, template_format="mustache")
+    assert prompt.format() == (
+        """This
+        no foos
+    is a test."""
+    )
+    assert prompt.input_variables == ["foo"]
+    assert prompt.input_schema.schema() == {
+        "title": "PromptInput",
+        "type": "object",
+        "properties": {"foo": {"title": "Foo", "type": "object"}},
+    }
+
 
 def test_prompt_from_template_with_partial_variables() -> None:
     """Test prompts can be constructed from a template with partial variables."""