[英]how to write expect_error in testthat to throw an error if there is no file in the directory?
我正在運行 R 代碼,如果目錄中沒有文件,則使用 testthat 拋出錯誤。 我的測試代碼如下,(我已經根據Waldi的回答進行了編輯)
test_that(desc = "Test for 'LoadData' Condition 1",
code = {
filePath = "./UnitTest/Data/Expected_Output2"
expect_error(LoadData(inputPath = filePath),"There's no file at ./UnitTest/Data/Expected_Output2")
}
)
我的 function 是,
LoadData = function(inputPath) {
if(!file.exists(inputPath){
stop(paste0("There's no file at ", inputPath))
}
}
我的測試代碼失敗並顯示此消息,
Error: `LoadData(inputPath = filePath)` threw an error with unexpected message.
Expected match: "There's no file at ./UnitTest/Data/Expected_Output_2"
Actual message: "cannot open the connection"
In addition: Warning message:
In open.connection(con, "rb") :
cannot open file './UnitTest/Data/Expected_Output_2': Permission denied
您只需要准確測試預期的錯誤消息:
library(testthat)
LoadData = function(inputPath) {
if(length(list.files(inputPath))==0){
stop(paste0("There's no file at ", inputPath))
}
}
test_that(desc = "Test for 'LoadData' Condition 1",
code = {
filePath = "./UnitTest/Data/Expected_Output2"
expect_error(LoadData(inputPath = filePath),"There's no file at ./UnitTest/Data/Expected_Output2")
}
)
由reprex package (v0.3.0) 於 2020 年 7 月 6 日創建
上述測試成功的原因是:
LoadData("./UnitTest/Data/Expected_Output2")
是以下錯誤:
Error in LoadData("./UnitTest/Data/Expected_Output2") :
There's no file at ./UnitTest/Data/Expected_Output2
解決此問題的一種方法是分配一個 json 文件,該文件實際上不存在於這樣的目錄中:
test_that(desc = "Test for 'LoadData' Condition 1",
code = {
filePath = "./UnitTest/Data/Expected_Output2/nofiles.json"
expect_error(LoadData(inputPath = filePath),"There's no file at ./UnitTest/Data/Expected_Output2/nofiles.json")
}
)
在這里我們需要小心理解,之前我們只是分配了一個空的路徑。 但是我們需要分配一個實際上不存在的假設文件。 這對我有用。 我的測試成功了。
聲明:本站的技術帖子網頁,遵循CC BY-SA 4.0協議,如果您需要轉載,請注明本站網址或者原文地址。任何問題請咨詢:yoyou2525@163.com.