ensure that we have an import_std configuration in the test-set; also…

…, update flake8

.flake8

@@ -7,6 +7,3 @@ ignore =
     E712,
     # line break before binary operator
     W503
-per-file-ignores =
-    # flake8 is just plain wrong here, contradicting black
-    .github/generate-job-matrix.py:E225,E231

.github/generate-job-matrix.py

@@ -127,6 +127,16 @@ def main():
             e.formatting == "std::format" and not e.config.std_format_support
         ),
     )
+    if args.preset:
+        # whatever the preset; we always want to have a test that does import_std;
+        # that requires a very specific configuration
+        collector.sample_combinations(
+            rgen=rgen,
+            min_samples_per_value=1,
+            formatting="std::format",
+            contracts="none",
+            config=configs["Clang-18 (x86-64)"],
+        )
     match args.preset:
         case None:
             pass
@@ -194,8 +204,6 @@ def main():
                     )
             case "counts":
                 print(f"Total combinations {len(data)}")
-                for (k, v), n in sorted(collector.per_value_counts.items()):
-                    print(f"  {k}={v}: {n}")
             case "none":
                 pass
             case _:

.github/job_matrix.py

@@ -64,9 +64,6 @@ def __init__(
         self.full_matrix = full_matrix
         self.hard_excludes = hard_excludes
         self.combinations: set[MatrixElement] = set()
-        self.per_value_counts: dict[tuple[str, typing.Any], int] = {
-            (k, v): 0 for k, options in full_matrix.items() for v in options
-        }
 
     def _make_submatrix(self, **overrides):
         new_matrix = dict(self.full_matrix)
@@ -80,12 +77,9 @@ def _add_combination(self, e: MatrixElement):
         if e in self.combinations or (
             self.hard_excludes is not None and self.hard_excludes(e)
         ):
-            return
+            return False
         self.combinations.add(e)
-        # update per_value_counts
-        for k, v in vars(e).items():
-            idx = (k, v)
-            self.per_value_counts[idx] = self.per_value_counts.get(idx, 0) + 1
+        return True
 
     def all_combinations(
         self,
@@ -118,7 +112,17 @@ def sample_combinations(
         for key, options in matrix.items():
             for value in options:
                 idx = (key, value)
-                missing[idx] = min_samples_per_value - self.per_value_counts.get(idx, 0)
+                missing[idx] = min_samples_per_value
+        for e in self.combinations:
+            for k, v in vars(e).items():
+                if v not in matrix[k]:
+                    break
+            else:
+                # this combination is in the submatrix
+                for k, v in vars(e).items():
+                    if v in matrix[k]:
+                        missing[k, v] -= 1
+        n_failed_tries = 0
         while missing:
             (force_key, force_option), remaining = next(iter(missing.items()))
             if remaining <= 0:
@@ -128,12 +132,22 @@ def sample_combinations(
             for key, options in matrix.items():
                 choice[key] = force_option if key == force_key else rgen.choice(options)
             cand = MatrixElement(**choice)
-            if filter and not filter(cand):
+            if filter is None or filter(cand):
+                added = self._add_combination(cand)
+            else:
+                added = False
+            if added:
+                n_failed_tries = 0
+            else:
+                n_failed_tries += 1
+                if n_failed_tries > 100:
+                    raise RuntimeError(
+                        "Unable to reach the requested minimum number of samples,"
+                        f" still missing the following\n{missing}"
+                    )
                 continue
-            self._add_combination(cand)
             for idx in choice.items():
-                if missing.pop(idx, 0) <= 0:
+                remaining = missing.pop(idx, 0) - 1
+                if remaining <= 0:
                     continue
-                remaining = min_samples_per_value - self.per_value_counts.get(idx, 0)
-                if remaining > 0:
-                    missing[idx] = remaining
+                missing[idx] = remaining

.pre-commit-config.yaml

@@ -33,7 +33,7 @@ repos:
       - id: isort
         args: [--profile, black, --multi-line, "3"]
   - repo: https://github.com/PyCQA/flake8
-    rev: 5.0.4
+    rev: 7.1.0
     hooks:
       - id: flake8