move realize to data.py, add tests

hypothesis-python/src/hypothesis/internal/conjecture/data.py

@@ -1225,7 +1225,16 @@ def __init__(self, conjecturedata: Optional["ConjectureData"], /) -> None:
     def per_test_case_context_manager(self):
         return contextlib.nullcontext()
 
-    def realize(self, value):
+    def realize(self, value: T) -> T:
+        """
+        Called whenever hypothesis requires a concrete (non-symbolic) value from
+        a potentially symbolic value. Hypothesis will not check that `value` is
+        symbolic before calling `realize`, so you should handle the case where
+        `value` is non-symbolic.
+
+        The returned value should be non-symbolic.
+        """
+
         return value
 
     @abc.abstractmethod
@@ -1897,6 +1906,14 @@ def permitted(f):
 }
 
 
+# eventually we'll want to expose this publicly, but for now it lives as psuedo-internal.
+def realize(value: object) -> object:
+    from hypothesis.control import current_build_context
+
+    context = current_build_context()
+    return context.data.provider.realize(value)
+
+
 class ConjectureData:
     @classmethod
     def for_buffer(

hypothesis-python/src/hypothesis/internal/conjecture/engine.py

@@ -30,6 +30,7 @@
     Set,
     Tuple,
     Union,
+    cast,
     overload,
 )
 
@@ -56,6 +57,7 @@
     Example,
     HypothesisProvider,
     InterestingOrigin,
+    IRKWargsType,
     IRNode,
     Overrun,
     PrimitiveProvider,
@@ -470,10 +472,15 @@ def test_function(self, data: ConjectureData) -> None:
                                 f"got {type(value)}"
                             )
 
+                        kwargs = cast(
+                            IRKWargsType,
+                            {
+                                k: data.provider.realize(v)
+                                for k, v in node.kwargs.items()
+                            },
+                        )
                         node.value = value
-                        node.kwargs = {
-                            k: data.provider.realize(v) for k, v in node.kwargs.items()
-                        }
+                        node.kwargs = kwargs
 
                 self._cache(data)
                 if data.invalid_at is not None:  # pragma: no branch # coverage bug?

hypothesis-python/src/hypothesis/provisional.py

@@ -22,7 +22,6 @@
 from importlib import resources
 
 from hypothesis import strategies as st
-from hypothesis.control import current_build_context
 from hypothesis.errors import InvalidArgument
 from hypothesis.internal.conjecture import utils as cu
 from hypothesis.strategies._internal.utils import defines_strategy
@@ -181,8 +180,3 @@ def url_encode(s):
         paths,
         st.just("") | _url_fragments_strategy,
     )
-
-
-def realize(value):
-    context = current_build_context()
-    return context.data.provider.realize(value)

hypothesis-python/tests/conjecture/test_alt_backend.py

@@ -24,6 +24,7 @@
     AVAILABLE_PROVIDERS,
     ConjectureData,
     PrimitiveProvider,
+    realize,
 )
 from hypothesis.internal.conjecture.engine import ConjectureRunner
 from hypothesis.internal.floats import SIGNALING_NAN
@@ -390,3 +391,27 @@ def test_function(n):
             match="expected .* from BadRealizeProvider.realize",
         ):
             test_function()
+
+
+class RealizeProvider(TrivialProvider):
+    avoid_realization = True
+
+    def realize(self, value):
+        if isinstance(value, int):
+            return 42
+        return value
+
+
+def test_realize():
+    with temp_register_backend("realize", RealizeProvider):
+
+        values = []
+
+        @given(st.integers())
+        @settings(backend="realize")
+        def test_function(n):
+            values.append(realize(n))
+
+        test_function()
+
+        assert all(n == 42 for n in values)