{testthat} 帶有 `expect_match` 的 `quasi_label` 拋出“錯誤：參數類型無效”

Question

我是 {testthat} 的新手，正在為修改字符串的 function 構建測試，預計會為某些輸入模式生成特定的 output。

作為一個例子（下面的代表）， add_excitement在其輸入字符串中添加了一個感嘆號。 當輸入“hello”時，它應該返回“hello;”； 當給定任何其他輸入時，它不應返回“hello”。 我想對一系列模式進行{testthat} 行為並返回信息性錯誤，這些錯誤指定導致錯誤的模式。

基於 {testthat} package 文檔，我相信我應該使用expect_match 。 但是，這會引發“無效參數類型”錯誤，而expect_identical有效。 我不明白為什么會這樣。 我的問題是：

• 為什么expect_identical而不是expect_match接受quasi_label參數？
• 我可以出於我的目的使用expect_identical而不是expect_match ，還是這會冒其他錯誤的風險？

這是一個代表：

library(testthat)
library(purrr)

patterns = c("hello", "goodbye", "cheers")
add_excitement <- function(pattern) paste0(pattern, "!")

# For a single pattern
show_failure(expect_identical(add_excitement(!!patterns[2]), "hello!"))
#> Failed expectation:
#> add_excitement("goodbye") not identical to "hello!".
#> 1/1 mismatches
#> x[1]: "goodbye!"
#> y[1]: "hello!"
try(
  show_failure(expect_match(add_excitement(!!patterns[2]), "hello!", fixed = TRUE,all = TRUE))
)
#> Error in !patterns[2] : invalid argument type

# For multiple patterns
purrr::map(
  patterns, 
  ~ show_failure(expect_identical(add_excitement(!!.), "hello!"))
)
#> Failed expectation:
#> add_excitement("goodbye") not identical to "hello!".
#> 1/1 mismatches
#> x[1]: "goodbye!"
#> y[1]: "hello!"
#> Failed expectation:
#> add_excitement("cheers") not identical to "hello!".
#> 1/1 mismatches
#> x[1]: "cheers!"
#> y[1]: "hello!"
#> [[1]]
#> NULL
#> 
#> [[2]]
#> NULL
#> 
#> [[3]]
#> NULL

try(
  purrr::map(
    patterns, 
    ~ show_failure(expect_match(add_excitement(!!.), "hello!", 
                                fixed = TRUE, all = TRUE)
    )
  )
)
#> Error in !. : invalid argument type

^{由reprex package (v0.3.0) 於 2021 年 2 月 4 日創建}

謝謝您的幫助！

Answer 1

在使用非標准評估bquote bquote()和eval() （而不是quasi_label() ) 以產生更多信息錯誤。

library(testthat)
library(purrr)

patterns = c("hello", "goodbye", "cheers")
add_excitement <- function(pattern) paste0(pattern, "!")

show_failure(eval(bquote(expect_match(add_excitement(.(patterns[2])), "hello!", fixed = TRUE, all = TRUE))))
#> Failed expectation:
#> add_excitement("goodbye") does not match "hello!".
#> Actual value: "goodbye!"


purrr::walk(
  patterns,
  ~ show_failure(eval(bquote(expect_match(add_excitement(.(.)), "hello!", fixed = TRUE, all = TRUE))))
)
#> Failed expectation:
#> add_excitement("goodbye") does not match "hello!".
#> Actual value: "goodbye!"
#> Failed expectation:
#> add_excitement("cheers") does not match "hello!".
#> Actual value: "cheers!"

^{由reprex package (v0.3.0) 於 2021 年 2 月 4 日創建}

或者對於一個整潔的版本：

library(testthat)
library(purrr)

patterns = c("hello", "goodbye", "cheers")
add_excitement <- function(pattern) paste0(pattern, "!")

expect_hello <- function(pattern) {
  show_failure(eval(bquote(expect_match(add_excitement(.(pattern)), "hello!", fixed = TRUE, all = TRUE))))
}

expect_hello(patterns[2])
#> Failed expectation:
#> add_excitement("goodbye") does not match "hello!".
#> Actual value: "goodbye!"

walk(patterns, expect_hello)
#> Failed expectation:
#> add_excitement("goodbye") does not match "hello!".
#> Actual value: "goodbye!"
#> Failed expectation:
#> add_excitement("cheers") does not match "hello!".
#> Actual value: "cheers!"

^{由reprex package (v0.3.0) 於 2021 年 2 月 4 日創建}

Answer 2

該錯誤與tidyeval bang bang 的使用有關!!運營商。
這已被取代，您提供的示例無需：

show_failure(expect_identical(add_excitement(patterns[2]), "hello!"))

# Failed expectation:
# add_excitement(patterns[2]) not identical to "hello!".
# 1/1 mismatches
# x[1]: "goodbye!"
# y[1]: "hello!"

show_failure(expect_match(add_excitement(patterns[2]), "hello!", fixed = TRUE,all = TRUE))

# Failed expectation:
# add_excitement(patterns[2]) does not match "hello!".
# Actual value: "goodbye!"

purrr::map(
  patterns, 
  ~ show_failure(expect_match(add_excitement(.x), "hello!", 
                              fixed = TRUE, all = TRUE)
  )
)

Failed expectation:
add_excitement(.x) does not match "hello!".
Actual value: "goodbye!"
Failed expectation:
add_excitement(.x) does not match "hello!".
Actual value: "cheers!"
[[1]]
NULL

[[2]]
NULL

[[3]]
NULL