Merge pull request #2137 from HypothesisWorks/DRMacIver/clean-up-engine

Clean up core test case generation logic

hypothesis-python/RELEASE.rst

@@ -0,0 +1,18 @@
+RELEASE_TYPE: minor
+
+This release significantly simplifies Hypothesis's internal logic for data
+generation, by removing a number of heuristics of questionable or unproven
+value.
+
+The results of this change will vary significantly from test to test. Most
+test suites will see significantly faster data generation and lower memory
+usage. The "quality" of the generated data may go up or down depending on your
+particular test suites.
+
+If you see any significant regressions in Hypothesis's ability to find bugs in
+your code as a result of this release, please file an issue to let us know.
+
+Users of the new  :ref:`targeted property-based testing <targeted-search>`
+functionality are reasonably likely to see *improvements* in data generation,
+as this release changes the search algorithm for targeted property based
+testing to one that is more likely to be productive than the existing approach.

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

@@ -698,6 +698,7 @@ class ConjectureResult(object):
     output = attr.ib()
     extra_information = attr.ib()
     has_discards = attr.ib()
+    target_observations = attr.ib()
     forced_indices = attr.ib(repr=False)
     examples = attr.ib(repr=False)
 
@@ -800,6 +801,7 @@ def as_result(self):
                 if self.extra_information.has_information()
                 else None,
                 has_discards=self.has_discards,
+                target_observations=self.target_observations,
                 forced_indices=self.forced_indices,
             )
             self.blocks.transfer_ownership(self.__result)
@@ -967,15 +969,6 @@ def draw_bits(self, n, forced=None):
         assert bit_length(result) <= n
         return result
 
-    @property
-    def block_starts(self):
-        while self.__block_starts_calculated_to < len(self.blocks):
-            i = self.__block_starts_calculated_to
-            self.__block_starts_calculated_to += 1
-            u, v = self.blocks.bounds(i)
-            self.__block_starts[v - u].append(u)
-        return self.__block_starts
-
     def draw_bytes(self, n):
         """Draw n bytes from the underlying source."""
         return int_to_bytes(self.draw_bits(8 * n), n)