map
map<Return>(fieldMappings: Record<keyof Return, (src: Current) => Return[keyof Return]>): RouteBuilder<Return>
Map fields from the current data to create a new object of a specified type. Sugar for .transform(mapper({...})): a specialized transformer that creates a new object by mapping fields from the source object.
// Map from API response to database model
.map<DbUser>({
id: (apiUser) => apiUser.userId,
name: (apiUser) => apiUser.fullName,
email: (apiUser) => apiUser.emailAddress
})
// Transform with computed fields
.map<Summary>({
fullName: (user) => `${user.firstName} ${user.lastName}`,
isActive: (user) => user.status === 'active',
displayEmail: (user) => user.email.toLowerCase()
})
// Map complex nested data
.map<OrderSummary>({
orderId: (order) => order.id,
customerName: (order) => order.customer.name,
totalAmount: (order) => order.items.reduce((sum, item) => sum + item.price, 0),
itemCount: (order) => order.items.length
})