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bash - 嵌套函数中的 BATS assert_failure

问题描述

语境

在编写期望抛出异常/错误的测试时，我在检测错误时遇到了一些困难。

该代码安装各种软件包并分别测试每个安装命令。有一个函数在每个函数之前进行一些预处理，然后调用安装函数，这个管理函数称为：run_main_functions，如果输入参数，它会传递参数。为了完整起见，代码run_main_functions包括：

#!/bin/bash
run_main_functions() {
    local SCRIPT_NAME=$1
    local EXTRA_ARGUMENT=$2
    SCRIPT_PATH=src/"$SCRIPT_NAME".sh
    local LOG_PATH=$LOG_LOCATION"$SCRIPT_NAME".txt
    
    chmod +x $SCRIPT_PATH
    
    # Remove old log files if exist
    if [ -f "$LOG_PATH" ] ; then
        rm "$LOG_PATH"
    fi
    
    # run the function that performs a single installation command
    if [ "$EXTRA_ARGUMENT" == "" ]; then
        source ./$SCRIPT_PATH $LOG_PATH
    else
        source ./$SCRIPT_PATH $LOG_PATH $EXTRA_ARGUMENT
    fi
}

然后这run_main_functions会调用一个函数count_nr_of_lines，如果它被输入一个无效的文件路径，我希望它会抛出一个错误。它包括：

#!/bin/bash
# Count the total nr of lines in an incoming file and export it.
count_nr_of_lines() {
    source src/hardcoded_variables.txt
    
    local LOG_PATH=$1
    local INPUT_PATH=$2
    
    # read content from file
    text_content=$(<$INPUT_PATH)
    
    # count the number of lines in that app
    total_nr_of_lines=$(echo "$text_content" | wc -l)
    
    # 4. Write the result of the content check to a log file.
    echo $total_nr_of_lines > "${TOTAL_NR_OF_LINES_IN_TARGET_FILEPATH}"
}
count_nr_of_lines "$@"

如果文件路径不存在，则检查是否count_nr_of_lines引发错误的测试INPUT_PATH是：

#!./test/libs/bats/bin/bats

load 'libs/bats-support/load'
load 'libs/bats-assert/load'
load 'libs/bats-file/load'

source test/helper.sh
source src/hardcoded_variables.txt
source src/helper.sh

mkdir -p src/logs

# Method that executes all tested main code before running tests.
setup() {
    
    # print test filename to screen.
    if [ "${BATS_TEST_NUMBER}" = 1 ];then
        echo "# Testfile: $(basename ${BATS_TEST_FILENAME})-" >&3
    fi
    
    # Declare filenames of files that perform commands
    declare -a script_names=("custom_install_4_energizedprotection")
    
    # Specify an additional array with arguments
    declare -a additional_arguments=("test/testfiles/nonexistant_filename.txt")

    # Loop through files that perform commands
    for i in "${!script_names[@]}"; do
        run_main_functions "${script_names[i]}" "${additional_arguments[i]}"    
    done
}

#---------------------------------------------------------------------------------------------------------------------------
@test "Tests whether an exception is thrown when computing the total nr of lines, if the file is not found." {
    ACTUAL_RESULT=$(<$TOTAL_NR_OF_LINES_IN_TARGET_FILEPATH)
    EXPECTED_OUTPUT="1"

    assert_failure
    #assert_equal "$ACTUAL_RESULT" "$EXPECTED_OUTPUT"
}

不存在文件的文件路径作为："test/testfiles/nonexistant_filename.txt". 测试失败并出现错误：

✗ Tests whether an exception is thrown when computing the total nr of lines, if the file is not found.
   (from function `apt_update' in file ./src/custom_install_4_energizedprotection.sh, line 10,
    from function `source' in file ./src/custom_install_4_energizedprotection.sh, line 18,
    from function `run_main_functions' in file src/helper.sh, line 19,
    from function `setup' in test file test/test_custom_install_4_1_energizedprotection.bats, line 28)
     `run_main_functions "${script_names[i]}" "${additional_arguments[i]}"' failed
   ./src/custom_install_4_energizedprotection.sh: line 10: test/testfiles/nonexistant_filename.txt: No such file or directory

所以在某种意义上，会抛出一个错误，这是意料之中的，但我希望 bats 测试能够捕获该错误/异常，并产生一个passed test.

问题

bats如果文件不存在，如何通过捕获/注册引发的错误来成功通过测试？

尝试

count_nr_of_lines我还尝试在函数中包含无效路径检测：

if [ ! -f "$INPUT_PATH" ] ; then
    exit 1
fi

但是，抛出一个显式错误会从测试失败中删除详细/错误消息，并且只会导致测试失败。

标签： bashtestingexceptionbats-core

解决方案

我不明白你为什么在设置中运行测试代码。这个怎么样

setup() {
    # print test filename to screen.
    if [ "${BATS_TEST_NUMBER}" = 1 ];then
        echo "# Testfile: $(basename ${BATS_TEST_FILENAME})-" >&3
    fi
}

#---------------------------------------------------------------------------------------------------------------------------
@test "Tests whether an exception is thrown when computing the total nr of lines, if the file is not found." {
    #ACTUAL_RESULT=$(<$TOTAL_NR_OF_LINES_IN_TARGET_FILEPATH)
    #EXPECTED_OUTPUT="1"

    # this will report an error if it has a non-zero return status
    run_main_functions "custom_install_4_energizedprotection" "test/testfiles/nonexistant_filename.txt"

    #assert_equal "$ACTUAL_RESULT" "$EXPECTED_OUTPUT"
}

我错过了您明确期望失败的观点。你可以

    ! run_main_functions ...

如果 run_main_functions 返回 OK 会出错，或者使用run命令

    run run_main_functions
    expect_failure

我认为这会起作用，但我对必须导出源函数有一个模糊的回忆（虽然我在文档中找不到任何关于它的参考）

在重新阅读文档后，而不是setup使用setup_file：

setup_file() {
    echo "# Testfile: $(basename ${BATS_TEST_FILENAME})-" >&3
}

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