tests/testthat/_snaps/snapshot.md

In testthat: Unit Testing for R

can snapshot output

y

y

y

y

can snapshot everything

Code
  f()
Output
  [1] "1"
Message <simpleMessage>
  2
Warning <simpleWarning>
  3
Error <simpleError>
  4

empty lines are preserved

Code
  f()
Output
  1

Message <simpleMessage>
  2

Warning <simpleWarning>
  3

Error <simpleError>
  4

multiple outputs of same type are collapsed

Code
  x <- 1
  y <- 1
  {
    message("a")
    message("b")
  }
Message <simpleMessage>
  a
  b
Code
  {
    warning("a")
    warning("b")
  }
Warning <simpleWarning>
  a
  b

can scrub output/messages/warnings/errors

Code
  secret()
Output
  [1] "<redacted>"
Message <simpleMessage>
  <redacted>
Warning <simpleWarning>
  <redacted>
Error <simpleError>
  <redacted>

Code
  print("secret")
Output
  [1] "****"

can capture error/warning messages

This is an error

This is a warning

can check error/warning classes

Code
  expect_snapshot_error(1)
Error <expectation_failure>
  1 did not generate error

Code
  expect_snapshot_error(1, class = "myerror")
Error <expectation_failure>
  1 did not generate error with class 'myerror'

Code
  expect_snapshot_warning(1)
Error <expectation_failure>
  1 did not generate warning

Code
  expect_snapshot_warning(1, class = "mywarning")
Error <expectation_failure>
  1 did not generate warning with class 'mywarning'

snapshot handles multi-line input

Code
  1 + 2
Output
  [1] 3
Code
  3 + 4
Output
  [1] 7
Code
  # this is a comment

snapshot captures output if visible

Code
  f_visible()
Output
  [1] "x"

Code
  f_invisible()

captures custom classes

Code
  f()
Message <testthat_greeting>
  Hello
Warning <testthat_farewell>
  Goodbye
Error <testthat_scream>
  Eeek!

even with multiple lines

a
b
c

a
b
c

can snapshot values

[
  "a",
  1.5,
  1,
  true
]

{
  "type": "list",
  "attributes": {},
  "value": [
    {
      "type": "character",
      "attributes": {},
      "value": ["a"]
    },
    {
      "type": "double",
      "attributes": {},
      "value": [1.5]
    },
    {
      "type": "integer",
      "attributes": {},
      "value": [1]
    },
    {
      "type": "logical",
      "attributes": {},
      "value": [true]
    }
  ]
}

list("a", 1.5, 1L, TRUE)

WAoAAAACAAMGAwACAwAAAAATAAAABAAAABAAAAABAAQACQAAAAFhAAAADgAAAAE/+AAAAAAA
AAAAAA0AAAABAAAAAQAAAAoAAAABAAAAAQ==

can control snapshot value details

1.1

tolerance passed to check_roundtrip

0.9

expect_snapshot() does not inject

Code
  x <- quote(!!foo)
  expect_equal(x, call("!", call("!", quote(foo))))

hint is informative

Code
  cat(snapshot_accept_hint("_default", "bar.R"))
Output
  * Run `snapshot_accept('bar.R')` to accept the change
  * Run `snapshot_review('bar.R')` to interactively review the change
Code
  cat(snapshot_accept_hint("foo", "bar.R"))
Output
  * Run `snapshot_accept('foo/bar.R')` to accept the change
  * Run `snapshot_review('foo/bar.R')` to interactively review the change

testthat documentation built on Jan. 21, 2022, 1:10 a.m.