test: add dedicated ALTER SYSTEM RESET ALL test

Author: Sean Loiselle

test/sql-feature-flags/mzcompose.py

@@ -100,6 +100,16 @@ def alter_system_reset(name: str) -> str:
     ).strip()
 
 
+def alter_system_reset_all() -> str:
+    """Generate a TD command that reset all system parameters."""
+    return dedent(
+        """
+        $ postgres-execute connection=mz_system
+        ALTER SYSTEM RESET ALL;
+        """
+    ).strip()
+
+
 class FeatureTestScenario:
     """
     A base class for all feature test scenarios.
@@ -166,6 +176,19 @@ def phase3(cls) -> str:
             ]
         )
 
+    @classmethod
+    def reset_all(cls) -> str:
+        return "\n\n".join(
+            [
+                cls.initialize(),
+                # The feature is immediately turned on because it's a default parameter.
+                statement_ok(cls.create_item(ordinal=1)),
+                query_ok(cls.query_item(ordinal=1)),
+                # We can drop item #1.
+                statement_ok(cls.drop_item(ordinal=1)),
+            ]
+        )
+
     @classmethod
     def feature_name(cls) -> str:
         """The name of the feature flag under test."""
@@ -314,6 +337,37 @@ def run_test(c: Composition, args: argparse.Namespace) -> None:
                 tmp.flush()
                 c.exec("testdrive", os.path.basename(tmp.name))
 
+    # Dedicated test for ALTER SYSTEM RESET ALL
+    with tempfile.NamedTemporaryFile(
+        mode="w",
+        dir=c.path,
+        prefix="phase-reset-all-",
+    ) as tmp:
+        tmp_buf = [header("(phase reset-all)", drop_schema=False)]
+        for scenario in scenarios:
+            # Turn all features off.
+            tmp_buf.append(alter_system_set(scenario.feature_name(), "off"))
+
+        # Run ALTER SYSTEM RESET ALL
+        tmp_buf.append(alter_system_reset_all())
+        for scenario in scenarios:
+            # Write each scenarios reset all data
+            tmp_buf.append(scenario.reset_all())
+
+        # Create MZ config with all features set on by default
+        materialized = Materialized(
+            unsafe_mode=False,
+            additional_system_parameter_defaults=list(
+                map(lambda scenario: "{}=on".format(scenario.feature_name()), scenarios)
+            ),
+        )
+        with c.override(materialized):
+            c.stop("materialized")
+            c.up("materialized")
+            tmp.write("\n\n".join(tmp_buf))
+            tmp.flush()
+            c.exec("testdrive", os.path.basename(tmp.name))
+
 
 def workflow_default(c: Composition, parser: WorkflowArgumentParser) -> None:
     parser.add_argument(