Spike: missing swapperName

[gomesalexandre]

Overview

Able to repro this one quite often locally, we should absolutely find the smoking gun
Gut feel is something is wrong state-wise, as clearing cache usually fixes this.

Claude spike below:

Able to repro this one quite often locally, we should absolutely find the smoking gun
Gut feel is something is wrong state-wise, as clearing cache usually fixes this.

Claude Spike

Error: Uncaught (in promise) Error: missing swapperName thrown at useTradeExecution.tsx:128

Root Cause: State desynchronization between activeQuoteMeta and tradeQuotes in Redux.

The Bug Flow

1. User gets quote and selects it → activeQuoteMeta is set
2. Something triggers clearTradeQuotes action (possibly quote refresh, input change, or component re-mount)
3. tradeQuotes are cleared BUT activeQuoteMeta is intentionally preserved (tradeQuoteSlice.ts:29)
4. User clicks "Sign and Broadcast"
5. selectActiveSwapperName selector checks if quote exists: tradeQuotes[activeQuoteMeta.swapperName][activeQuoteMeta.identifier]
6. Quote doesn't exist (was cleared) → selector returns undefined
7. Execution fails: "missing swapperName"

Key Code Locations

Where activeQuoteMeta is preserved:
src/state/slices/tradeQuoteSlice/tradeQuoteSlice.ts:25-31

clearTradeQuotes: create.reducer(state => ({
  ...initialState,
  tradeExecution: state.tradeExecution,
  activeQuoteMeta: state.activeQuoteMeta,  // ← Preserved to handle "backing out from preview"
  sortOption: state.sortOption,
}))

Where swapperName check happens:
src/state/slices/tradeQuoteSlice/selectors.ts:214-227

selectActiveSwapperName: (activeQuoteMetaOrDefault, tradeQuotes) => {
  if (activeQuoteMetaOrDefault === undefined) return
  if (tradeQuotes[activeQuoteMetaOrDefault.swapperName]?.[activeQuoteMetaOrDefault.identifier]) {
    return activeQuoteMetaOrDefault.swapperName
  }
  // Returns undefined if quote doesn't exist
}

Investigation Needed

1. When does clearTradeQuotes get called?

   • During quote refresh?
   • When user changes input amounts?
   • On component re-mount?
   • Add logging to track all clearTradeQuotes dispatches

2. Is preserving activeQuoteMeta still necessary?

   • Comment mentions "backing out from preview"
   • Test: preview → back → preview navigation
   • Does it actually need the preserved quote, or can it re-select?

3. Race condition timing:

   • Is there a timing window between selecting quote and executing?
   • Could quote refresh happen while user is on confirm screen?

Potential Fixes

Option A: Stop preserving activeQuoteMeta (simplest)

• Remove activeQuoteMeta: state.activeQuoteMeta from clearTradeQuotes reducer
• Risk: May break navigation UX (quotes need re-selection when backing out)

Option B: Conditional preservation

• Add parameter to clearTradeQuotes to control when to preserve
• Only preserve when needed for navigation
• Clear when quote refresh happens

Option C: Validate quote exists before execution

• In execution hook, check if quote still exists in tradeQuotes
• If not, re-fetch or show error to user
• More defensive but doesn't fix root cause

Recommended Approach

Investigate Option A first:

1. Remove activeQuoteMeta preservation
2. Test swap execution (should fix the error)
3. Test navigation flow (preview → back → preview)
4. If navigation breaks, implement Option B

References and additional details

N/A

Acceptance Criteria

• That sneaky error is gone

Need By Date

No response

Screenshots/Mockups

No response

Estimated effort

No response

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🔗 Related PRs

#10219 - fix: align trade quotes and trade input loading states [merged]
#10412 - feat: swapper remove status screen [merged]
#10457 - feat: make swaps by id partial record [merged]
#10794 - fix: leverage query cache for fiat ramps [merged]
#11132 - fix: swapper crashing on subsequent selected swapper failing [merged]

👤 Suggested Assignees

• gomesalexandre
• NeOMakinG

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