Response query

The res object available inside the vars, assertions, scripting, and testing contexts can be invoked as a function to query nested response data.

Think of it as lodash.get() on steroids.

If you're not familiar, lodash.get() is a utility function from the Lodash library that lets you safely access nested properties in JavaScript objects.

res('order.total')

Response query filtering (including [?] with filter functions and object predicates) works in both Safe Mode and Developer Mode.

Examples

const data = {
  customer: {
    address: {
      city: "bangalore"
    },
    orders: [
      {
        id: "order-1",
        items: [
          { id: 1, amount: 10 },
          { id: 2, amount: 20 }
        ]
      },
      {
        id: "order-2",
        items: [
          { id: 3, amount: 30 },
          { id: 4, amount: 40 }
        ]
      }
    ]
  },
};

Query	Output
res("customer.address.city")	bangalore
res("customer.orders.items.amount")	[10, 20, 30, 40]
res("customer.orders.items.amount[0]")	10
res("..items.amount")	[10, 20, 30, 40]
res("..amount")	[10, 20, 30, 40]
res("..items.amount[0]")	10
res("..items[0].amount")	10
res("..items[5].amount")	undefined
res("..id")	["order-1", 1, 2, "order-2", 3, 4]
res("customer.orders.foo")	undefined
res("..customer.foo")	undefined
res("..address")	[{ city: "bangalore" }]
res("..address[0]")	{ city: "bangalore" }

API

Standard dot notation

Example:

res('customer.orders.items.amount')

Deep navigation with double dots

Example:

res('..items.amount')

Array indexing

Example:

res('..items[0].amount')

Array filtering with a filter function

Use [?] with a corresponding filter function to select matching items. [?] works with both standard dot notation and deep navigation (..).

Example:

res('customer.orders.items[?].amount', i => i.amount > 20)
res('..items[?].amount', i => i.amount > 20)

Array filtering with an object predicate

Use [?] with an object to match items by property values. This is equivalent to i => i.id === 2 && i.amount === 20. [?] works with both standard dot notation and deep navigation (..).

res('customer.orders.items[?]', { id: 2, amount: 20 })
res('..items[?]', { id: 2, amount: 20 })

Array mapping with a mapper function

Use [?] with a function that returns a transformed value to map over items. [?] works with both standard dot notation and deep navigation (..).

Example:

res('customer.orders.items..amount[?]', amt => amt + 10)
res('..items..amount[?]', amt => amt + 10)