Fix schedule edit double-encoding header fields

[laurakwhit]

Description & motivation 💭

Header fields from the server are already base64-encoded Payloads. Editing a schedule was unconditionally re-encoding them, wrapping each Payload inside a new Payload. Each subsequent edit/save compounded the encoding, which could lead to Workflow Task Failures.

This PR adds an isBase64EncodedPayload check to skip encoding for already-encoded inputs in encodePayloads.

Screenshots (if applicable) 📸

Design Considerations 🎨

Testing 🧪

How was this tested 👻

• Manual testing
• E2E tests added
• Unit tests added

Steps for others to test: 🚶🏽‍♂️🚶🏽‍♀️

1. Modify this Go sample to create a schedule with headers

In schedule/starter/main.go, register a context propagator and set the header value in the context:

func main() {
	[...]
	ctx = context.WithValue(ctx, ctxpropagation.PropagateKey, &ctxpropagation.Values{Key: "x-custom-header", Value: "header-value"})
	c, err := client.Dial(client.Options{
		[...]
		ContextPropagators: []workflow.ContextPropagator{ctxpropagation.NewContextPropagator()},
	})
    [...]
  }    

Remove the deferred delete so the schedule sticks around for UI testing.

2. Run the sample

Terminal 1: run the worker
go run schedule/worker/main.go

Terminal 2: create the schedule
go run schedule/starter/main.go

3. Test in the UI

   • Open the schedule in the UI
   • Open browser DevTools Network tab
   • Edit and save without changing anything and inspect the request payload
     • Verify the header fields are NOT double-wrapped in a new Payload
   • Verify the schedule still triggers successfully after the edit
   • Edit and save a second time
     • Verify the request payload looks identical to step 3
   • Verify the triggered workflow completes without a Workflow Task Failure

Checklists

Draft Checklist

Merge Checklist

Issue(s) closed

DT-3821

Docs

Any docs updates needed?

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Project	Deployment	Actions	Updated (UTC)
holocene	Ready	Preview, Comment	Apr 9, 2026 9:07pm

[temporal-cicd]

Warnings

⚠️

📊 Strict Mode: 35 errors in 2 files (3.2% of 1085 total) src/lib/utilities/encode-payload.ts (1) L69:14: Type 'null' is not assignable to type 'IPayload[]'. src/lib/stores/schedules.ts (34) L47:4: 'body.schedule' is possibly 'undefined'. L47:4: 'body.schedule.spec' is possibly 'null' or 'undefined'. L48:4: 'body.schedule' is possibly 'undefined'. L48:4: 'body.schedule.spec' is possibly 'null' or 'undefined'. L49:4: 'body.schedule' is possibly 'undefined'. L49:4: 'body.schedule.spec' is possibly 'null' or 'undefined'. L51:42: Argument of type 'string | undefined' is not assignable to parameter of type 'string'. L53:4: 'body.schedule' is possibly 'undefined'. L53:4: 'body.schedule.spec' is possibly 'null' or 'undefined'. L56:4: 'body.schedule' is possibly 'undefined'. L56:4: 'body.schedule.spec' is possibly 'null' or 'undefined'. L57:4: 'body.schedule' is possibly 'undefined'. L57:4: 'body.schedule.spec' is possibly 'null' or 'undefined'. L64:4: 'body.schedule' is possibly 'undefined'. L64:4: 'body.schedule.spec' is possibly 'null' or 'undefined'. L75:4: 'body.schedule' is possibly 'undefined'. L75:4: 'body.schedule.spec' is possibly 'null' or 'undefined'. L76:4: 'body.schedule' is possibly 'undefined'. L76:4: 'body.schedule.spec' is possibly 'null' or 'undefined'. L108:65: Property 'message' does not exist on type '{}'. L115:4: Type '{ indexedFields: { indexedFields?: { [k: string]: IPayload; } | null | undefined; }; } | null' is not assignable to type 'ISearchAttributes | null | undefined'. L135:10: Type '{ indexedFields: { indexedFields?: { [k: string]: IPayload; } | null | undefined; }; } | null' is not assignable to type 'ISearchAttributes | null | undefined'. L136:12: 'workflowSearchAttributes' is possibly 'undefined'. L140:43: Argument of type '{ type: "Unspecified" | "Keyword" | "Text" | "Int" | "Double" | "Bool" | "KeywordList" | "Datetime"; label: string; value?: any; }[] | undefined' is not assignable to parameter of type '{ type: "Unspecified" | "Keyword" | "Text" | "Int" | "Double" | "Bool" | "KeywordList" | "Datetime"; label: string; value?: any; }[]'. L197:65: Property 'message' does not exist on type '{}'. L205:4: Type '{ indexedFields: { indexedFields?: { [k: string]: IPayload; } | null | undefined; }; } | null' is not assignable to type 'ISearchAttributes | null | undefined'. L210:13: 'schedule.action' is possibly 'null' or 'undefined'. L215:10: Type '{ indexedFields: { indexedFields?: { [k: string]: IPayload; } | null | undefined; }; } | null' is not assignable to type 'ISearchAttributes | null | undefined'. L221:17: 'body.schedule' is possibly 'undefined'. L221:17: 'body.schedule.action' is possibly 'null' or 'undefined'. L232:65: Property 'message' does not exist on type '{}'. L238:4: 'body.schedule' is possibly 'undefined'. L241:4: 'body.schedule' is possibly 'undefined'. L241:4: 'body.schedule.spec' is possibly 'null' or 'undefined'.

Generated by 🚫 dangerJS against cc42ff4

[temporal-cicd]

• ⚠️ Type 'null' is not assignable to type 'IPayload[]'.

[GiantRobots]

Not a fan of ternaries