Properly ignore unknown fields when parsing history JSON (#175)

Fixes #173
temporalio · Jan 10, 2024 · 53a8a3d · 53a8a3d
1 parent 0e592ee
commit 53a8a3d
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Showing 2 changed files with 46 additions and 1 deletion.
diff --git a/src/Temporalio/Common/WorkflowHistory.cs b/src/Temporalio/Common/WorkflowHistory.cs
@@ -22,6 +22,9 @@ public record WorkflowHistory(string Id, IReadOnlyCollection<HistoryEvent> Event
         private static readonly JsonSerializerOptions JsonSerializerOptions =
             new() { Converters = { JsonCommonTypeConverter.Instance } };
 
+        private static readonly JsonParser ProtoJsonParser = new(
+            JsonParser.Settings.Default.WithIgnoreUnknownFields(true));
+
         /// <summary>
         /// Interface for fixes to apply.
         /// </summary>
@@ -71,7 +74,7 @@ private static WorkflowHistory FromJson(string workflowId, Dictionary<string, ob
             // serialize the altered, then deserialize again using Proto JSON
             HistoryJsonFixer.Fix(historyObj);
             var fixedJson = JsonSerializer.Serialize(historyObj);
-            var history = JsonParser.Default.Parse<History>(fixedJson);
+            var history = ProtoJsonParser.Parse<History>(fixedJson);
             return new(workflowId, history.Events);
         }
 

diff --git a/tests/Temporalio.Tests/Common/WorkflowHistoryTests.cs b/tests/Temporalio.Tests/Common/WorkflowHistoryTests.cs
@@ -97,4 +97,46 @@ void Replace(string prevVal, string newVal)
         // But that our history parser succeeds
         var newHistory = AssertHistoryJson();
     }
+
+    [Fact]
+    public void FromJson_UnknownField()
+    {
+        // Format some JSON history, then sneak in a new field on an event, then
+        // try to parse
+        var history = new History();
+        history.Events.Add(new HistoryEvent()
+        {
+            EventType = EventType.RequestCancelExternalWorkflowExecutionFailed,
+            RequestCancelExternalWorkflowExecutionFailedEventAttributes = new()
+            {
+                Cause = CancelExternalWorkflowExecutionFailedCause.ExternalWorkflowExecutionNotFound,
+            },
+        });
+        history.Events.Add(new HistoryEvent()
+        {
+            WorkflowExecutionStartedEventAttributes = new()
+            {
+                TaskQueue = new() { Kind = TaskQueueKind.Sticky },
+            },
+        });
+        var historyJson = JsonFormatter.Default.Format(history);
+
+        // Alter the first event to have an extra field
+        var eventStart = "\"events\": [ { ";
+        var eventStartIndex = historyJson.IndexOf(eventStart);
+        Assert.True(eventStartIndex > 0);
+        historyJson = historyJson.Substring(0, eventStartIndex + eventStart.Length) +
+            "\"someField\": \"someValue\", " +
+            historyJson.Substring(eventStartIndex + eventStart.Length);
+
+        // Confirm parse failure
+        var exc = Assert.Throws<InvalidProtocolBufferException>(
+            () => JsonParser.Default.Parse<History>(historyJson));
+        Assert.Contains("Unknown field: someField", exc.Message);
+
+        // But confirm history JSON parsing ignores
+        var workflowHistory = WorkflowHistory.FromJson("workflow-id", historyJson);
+        Assert.True(workflowHistory.Events.Count == 2);
+        Assert.Equal(EventType.RequestCancelExternalWorkflowExecutionFailed, workflowHistory.Events.First().EventType);
+    }
 }