Fix "InputBlock" hint validation (#726)

* 🚑 Accept correct type at "Option" object
* 🚑 Fix hint check at "InputBlock"
* 🚑 Undo "Optional" API changes
* ☔ Test "InputBlock.hint" validation

Author: jourdanrodrigues

slack/web/classes/blocks.py

@@ -310,7 +310,11 @@ def _validate_label_length(self):
 
     @JsonValidator(f"hint attribute cannot exceed {hint_max_length} characters")
     def _validate_hint_length(self):
-        return self.hint is None or len(self.hint) <= self.hint_max_length
+        return (
+            self.hint is None
+            or self.hint.text is None
+            or len(self.hint.text) <= self.label_max_length
+        )
 
     @JsonValidator(
         (

tests/web/classes/test_blocks.py

@@ -584,7 +584,23 @@ def test_document(self):
                     "text": "Label",
                     "emoji": True
                 }
-            }
+            },
+            {
+                "type": "input",
+                "element": {
+                    "type": "plain_text_input",
+                },
+                "label": {
+                    "type": "plain_text",
+                    "text": "Label",
+                    "emoji": True,
+                },
+                "hint": {
+                    "type": "plain_text",
+                    "text": "some hint",
+                    "emoji": True,
+                },
+            },
         ]
         for input in blocks:
             self.assertDictEqual(input, InputBlock(**input).to_dict())