typing, tests, release notes

hypothesis-python/RELEASE.rst

@@ -0,0 +1,3 @@
+RELEASE_TYPE: patch
+
+This patch migrates the :obj:`~hypothesis.Phase.explain` :ref:`phase <phases>` to our IR layer (:issue:`3921`). This should improve both its speed and precision.

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

@@ -627,7 +627,7 @@ def ir_node(self, ir_node: "IRNode") -> None:
         def finish(self):
             return tuple(self.result)
 
-    ir_tree_nodes: "tuple[IRNode]" = calculated_example_property(_ir_tree_nodes)
+    ir_tree_nodes: "tuple[IRNode, ...]" = calculated_example_property(_ir_tree_nodes)
 
     class _label_indices(ExampleProperty):
         def start_example(self, i: int, label_index: int) -> None:

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

@@ -9,6 +9,7 @@
 # obtain one at https://mozilla.org/MPL/2.0/.
 
 from collections import defaultdict
+from collections.abc import Sequence
 from typing import TYPE_CHECKING, Callable, Optional, TypeVar, Union
 
 import attr
@@ -22,6 +23,7 @@
 from hypothesis.internal.conjecture.data import (
     ConjectureData,
     ConjectureResult,
+    IRNode,
     Status,
     ir_to_buffer,
     ir_value_equal,
@@ -391,7 +393,7 @@ def cached_test_function_ir(self, tree):
         self.check_calls()
         return result
 
-    def consider_new_tree(self, tree):
+    def consider_new_tree(self, tree: Sequence[IRNode]) -> bool:
         tree = tree[: len(self.nodes)]
 
         if startswith(tree, self.nodes):

hypothesis-python/tests/conjecture/test_engine.py

@@ -1578,6 +1578,32 @@ def test(cd):
     assert runner.call_count == 1
 
 
+@given(ir_nodes(was_forced=False))
+def test_overruns_with_extend_are_not_cached(node):
+    assume(compute_max_children(node.ir_type, node.kwargs) > 100)
+
+    def test(cd):
+        _draw(cd, node)
+        _draw(cd, node)
+
+    runner = ConjectureRunner(test)
+    assert runner.call_count == 0
+
+    data = runner.cached_test_function_ir([node])
+    assert runner.call_count == 1
+    assert data.status is Status.OVERRUN
+
+    # cache hit
+    data = runner.cached_test_function_ir([node])
+    assert runner.call_count == 1
+    assert data.status is Status.OVERRUN
+
+    # cache miss
+    data = runner.cached_test_function_ir([node], extend=1)
+    assert runner.call_count == 2
+    assert data.status is Status.VALID
+
+
 def test_simulate_to_evicted_data(monkeypatch):
     # test that we do not rely on the false invariant that correctly simulating
     # a data to a result means we have that result in the cache, due to e.g.

hypothesis-python/tests/conjecture/test_ir.py

@@ -401,6 +401,12 @@ def test_ir_node_equality(node):
     assert node != 42
 
 
+@given(ir_nodes(was_forced=True))
+def test_cannot_modify_forced_nodes(node):
+    with pytest.raises(AssertionError):
+        node.copy(with_value=42)
+
+
 def test_data_with_empty_ir_tree_is_overrun():
     data = ConjectureData.for_ir_tree([])
     with pytest.raises(StopTest):

hypothesis-python/tests/conjecture/test_junkdrawer.py

@@ -23,6 +23,8 @@
     clamp,
     replace_all,
     stack_depth_of_caller,
+    startswith,
+    endswith,
 )
 
 
@@ -202,3 +204,13 @@ def zero(n):
 
     assert x.find(zero) == 0
     assert count[0] == 21
+
+
+@given(st.binary(), st.binary())
+def test_startswith(b1, b2):
+    assert b1.startswith(b2) == startswith(b1, b2)
+
+
+@given(st.binary(), st.binary())
+def test_endswith(b1, b2):
+    assert b1.endswith(b2) == endswith(b1, b2)