Function checkDuplicates

src/keybindings/validate.ts:336–368

(
  blocks: KeybindingBlock[],
)

 * Only checks user bindings (not default + user merged).
 */
export function checkDuplicates(
  blocks: KeybindingBlock[],
): KeybindingWarning[] {
  const warnings: KeybindingWarning[] = []
  const seenByContext = new Map<string, Map<string, string>>()

  for (const block of blocks) {
    const contextMap =
      seenByContext.get(block.context) ?? new Map<string, string>()
    seenByContext.set(block.context, contextMap)

    for (const [key, action] of Object.entries(block.bindings)) {
      const normalizedKey = normalizeKeyForComparison(key)
      const existingAction = contextMap.get(normalizedKey)

      if (existingAction && existingAction !== action) {
        warnings.push({
          type: 'duplicate',
          severity: 'warning',
          message: `Duplicate binding "${key}" in ${block.context} context`,
          key,
          context: block.context,
          action: action ?? 'null (unbind)',
          suggestion: `Previously bound to "${existingAction}". Only the last binding will be used.`,
        })
      }

      contextMap.set(normalizedKey, action ?? 'null')
    }
  }

  return warnings
}

/**
 * Check for reserved shortcuts that may not work.