Add some basic checks on SWF decisions, more to come later

tests/test_swf/test_decision_tasks.py

@@ -6,6 +6,7 @@ from moto.swf import swf_backend
 from moto.swf.exceptions import (
     SWFUnknownResourceFault,
     SWFValidationException,
+    SWFDecisionValidationException,
 )
 
 from .utils import mock_basic_workflow_type
@@ -157,3 +158,36 @@ def test_respond_decision_task_completed_with_complete_workflow_execution():
         "DecisionTaskCompleted",
         "WorkflowExecutionCompleted",
     ])
+
+@mock_swf
+def test_respond_decision_task_completed_with_close_decision_not_last():
+    conn = setup_workflow()
+    resp = conn.poll_for_decision_task("test-domain", "queue")
+    task_token = resp["taskToken"]
+
+    decisions = [
+        { "decisionType": "CompleteWorkflowExecution" },
+        { "decisionType": "WeDontCare" },
+    ]
+
+    conn.respond_decision_task_completed.when.called_with(
+        task_token, decisions=decisions
+    ).should.throw(SWFValidationException, r"Close must be last decision in list")
+
+@mock_swf
+def test_respond_decision_task_completed_with_invalid_decision_type():
+    conn = setup_workflow()
+    resp = conn.poll_for_decision_task("test-domain", "queue")
+    task_token = resp["taskToken"]
+
+    decisions = [
+        { "decisionType": "BadDecisionType" },
+        { "decisionType": "CompleteWorkflowExecution" },
+    ]
+
+    conn.respond_decision_task_completed.when.called_with(
+        task_token, decisions=decisions
+        ).should.throw(
+            SWFDecisionValidationException,
+            r"Value 'BadDecisionType' at 'decisions.1.member.decisionType'"
+        )

tests/test_swf/test_exceptions.py

@@ -11,6 +11,7 @@ from moto.swf.exceptions import (
     SWFWorkflowExecutionAlreadyStartedFault,
     SWFDefaultUndefinedFault,
     SWFValidationException,
+    SWFDecisionValidationException,
 )
 from moto.swf.models import (
     WorkflowType,
@@ -124,3 +125,28 @@ def test_swf_validation_exception():
         "__type": "com.amazon.coral.validate#ValidationException",
         "message": "Invalid token",
     })
+
+def test_swf_decision_validation_error():
+    ex = SWFDecisionValidationException([
+        { "type": "null_value",
+          "where": "decisions.1.member.startTimerDecisionAttributes.startToFireTimeout" },
+        { "type": "bad_decision_type",
+          "value": "FooBar",
+          "where": "decisions.1.member.decisionType",
+          "possible_values": "Foo, Bar, Baz"},
+    ])
+
+    ex.status.should.equal(400)
+    ex.error_code.should.equal("ValidationException")
+    ex.body["__type"].should.equal("com.amazon.coral.validate#ValidationException")
+
+    msg = ex.body["message"]
+    msg.should.match(r"^2 validation errors detected:")
+    msg.should.match(
+        r"Value null at 'decisions.1.member.startTimerDecisionAttributes.startToFireTimeout' "\
+        r"failed to satisfy constraint: Member must not be null;"
+    )
+    msg.should.match(
+        r"Value 'FooBar' at 'decisions.1.member.decisionType' failed to satisfy constraint: " \
+        r"Member must satisfy enum value set: \[Foo, Bar, Baz\]"
+    )