Catch composable syntax err for options and defaults (#678)

* catch syntax error for options and defaults

* work both ways

* format

Author: seungpark

snooty/parser.py

@@ -900,6 +900,18 @@ def handle_composable(self, node: n.ComposableDirective) -> None:
                     "composable-tutorial", "option_ids", "at least one", node.start[0]
                 )
             )
+            return
+
+        if len(default_ids) != len(option_ids):
+            self.diagnostics.append(
+                InvalidChildCount(
+                    "composable-tutorial",
+                    "defaults",
+                    str(len(option_ids)),
+                    node.start[0],
+                )
+            )
+            return
 
         # get the expected composable options from the spec
         spec_composables = specparser.Spec.get(

snooty/test_postprocess.py

@@ -18,6 +18,7 @@
     GuideAlreadyHasChapter,
     InvalidChapter,
     InvalidChild,
+    InvalidChildCount,
     InvalidContextError,
     InvalidIAEntry,
     InvalidIALinkedData,
@@ -4272,6 +4273,52 @@ def test_composable_tutorial_errors() -> None:
             MissingChild,
         ]
 
+    # below test has mismatch of options and default ids (defaults has more ids than options)
+    with make_test(
+        {
+            Path(
+                "source/index.txt"
+            ): """
+.. composable-tutorial::
+   :options: interface, language, cluster-topology, cloud-provider
+   :defaults: driver, None, repl
+
+   .. selected-content::
+      :selections: driver, None, repl
+        """
+        }
+    ) as result:
+        diagnostics = result.diagnostics[FileId("index.txt")]
+        assert len(diagnostics) >= 1
+        invalidChildError = next(
+            (d for d in diagnostics if isinstance(d, InvalidChildCount)), None
+        )
+        assert invalidChildError
+        assert "defaults" in invalidChildError.message
+
+    # below test has mismatch of options and default ids (defaults has less ids than options)
+    with make_test(
+        {
+            Path(
+                "source/index.txt"
+            ): """
+.. composable-tutorial::
+   :options: interface, language, cluster-topology
+   :defaults: driver, None, repl, gcp
+
+   .. selected-content::
+      :selections: driver, None, repl, gcp
+        """
+        }
+    ) as result:
+        diagnostics = result.diagnostics[FileId("index.txt")]
+        assert len(diagnostics) >= 1
+        invalidChildError = next(
+            (d for d in diagnostics if isinstance(d, InvalidChildCount)), None
+        )
+        assert invalidChildError
+        assert "defaults" in invalidChildError.message
+
 
 def test_composable_headings() -> None:
     with make_test(