ios app如何"知道"运行单元测试

Question

我知道我可以开始我的应用程序的单元测试xcodebuild,但我想知道是什么告诉应用程序在启动期间运行测试,是一个特殊的参数发送到应用程序或它编译不同以运行测试(使用XCTest )？

Answer 1

Xcode使用xctest和RunTargetUnitTests脚本(from /Developer/Tools/RunTargetUnitTests)进行单元测试.

xctest注入dynamic library(测试工具包具有单独的线程,用于它的工作)到二进制文件中,注入提供对dylib进程内存的访问(它可以访问您的进程内存中的类/实例),并且它能够执行调用并进行单元测试.从调试器接收来自设备/模拟器的回调(没有用于单元测试的特殊技术).

简单地说:该项目与test scheme往常一样编译,但它将链接动态库,它会使您的进程内存木马,并进行测试.

还有非常有用的信息:

RunUnitTests接受ENVIRONMENT variables,这里有一些有趣的

TEST_HOST - 要"注入"指定单元测试包的可执行文件的完整路径.对于应用程序,它必须是其包装器中应用程序的完整路径.不要为框架作品或库设置此项.

TEST_RIG - 可执行文件的完整路径,用作测试装备,而不是CPlusTestRig或otest.可执行文件必须将测试包的路径作为其最终参数.其DYLD_FRAMEWORK_PATH和DYLD_LIBRARY_PATH将配置为在执行之前指向BUILT_PRODUCTS_DIR.如果您使用其中一个默认测试装备,请不要设置此项.

也
BUNDLE_LOADER用作链接器选项,指示链接器链接Testing dynamic library到指定的二进制文件.

测试包目标模板在调用的最末端具有shell脚本构建阶段/Developer/Tools/RunUnitTests.RunUnitTests查看它通过其环境传递的构建设置,并根据该信息确定如何在测试包中运行测试.

如果您正在测试框架,RunUnitTests将运行相应的测试装备并告诉它加载并运行捆绑中的测试.由于您的测试包应链接到您的框架,因此当测试装置加载您的包时,您的框架将被加载.

如果您正在测试应用程序,则需要在其配置的构建设置中将应用程序指定为测试包的测试主机和分发包加载器.Bundle Loader设置告诉链接器将您的bundle与正在加载它的应用程序链接,就像应用程序是一个框架一样,允许您从bundle中引用应用程序中的类和其他符号,而不实际将它们包含在bundle中.测试主机设置告诉RunUnitTests启动指定的应用程序并将测试包注入其中以运行其测试.

欲了解更多信息,请参阅man页RunTargetUnitTests/xctest

https://developer.apple.com/library/mac/documentation/Darwin/Reference/Manpages/man1/RunTargetUnitTests.1.html#//apple_ref/doc/man/1/RunTargetUnitTests

https://developer.apple.com/library/mac/documentation/Darwin/Reference/Manpages/man1/xctest.1.html

这是RunTargetUnitTests脚本

#!/bin/sh

#
# Copyright (c) 2005-2013 Apple Inc.  All rights reserved.
#

# Copyright (c) 1997-2005, Sen:te (Sente SA).  All rights reserved.
#
# Use of this source code is governed by the following license:
# 
# Redistribution and use in source and binary forms, with or without modification, 
# are permitted provided that the following conditions are met:
# 
# (1) Redistributions of source code must retain the above copyright notice, 
# this list of conditions and the following disclaimer.
# 
# (2) Redistributions in binary form must reproduce the above copyright notice, 
# this list of conditions and the following disclaimer in the documentation 
# and/or other materials provided with the distribution.
# 
# THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS ``AS IS'' 
# AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 
# WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. 
# IN NO EVENT SHALL Sente SA OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 
# SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT 
# OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) 
# HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, 
# OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, 
# EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
# 
# Note: this license is equivalent to the FreeBSD license.
# 
# This notice may not be removed from this file.

if [ "${NATIVE_ARCH_ACTUAL}" = "" ]; then
    NATIVE_ARCH_ACTUAL=`arch`
fi

if [ "${ARCHS}" = "" ]; then
    ARCHS=`arch`
fi

if [ "${DEVELOPER_DIR}" = "" ]; then
    DEVELOPER_DIR="${SYSTEM_DEVELOPER_DIR}"
fi 

if [ "${OTEST}" = "" ]; then
    OTEST="${DEVELOPER_DIR}/Tools/otest"
fi

if [ "${OTEST_TARGET}" = "" ]; then
    OTEST_TARGET="${BUILT_PRODUCTS_DIR}/${FULL_PRODUCT_NAME}"
fi

RunTargetUnitTestsForArch() {
    echo "${DEVELOPER_DIR}/Tools/RunTargetUnitTests:0: note: Starting tests for ${1}"

    if [ "${DYLD_FRAMEWORK_PATH}" = "" ] ; then
        DYLD_FRAMEWORK_PATH="${BUILT_PRODUCTS_DIR}:${DEVELOPER_DIR}/Library/Frameworks"
    else
        DYLD_FRAMEWORK_PATH="${BUILT_PRODUCTS_DIR}:${DEVELOPER_DIR}/Library/Frameworks:${DYLD_FRAMEWORK_PATH}"
    fi

    export DYLD_FRAMEWORK_PATH

    echo "OTEST=${OTEST}"

    arch -arch "${1}" "${OTEST}" "${OTEST_TARGET}"

    unset DYLD_FRAMEWORK_PATH

    echo "${DEVELOPER_DIR}/Tools/RunTargetUnitTests:0: note: Completed tests for ${1}"
}

SkipTargetUnitTestsForArch() {
    echo "${DEVELOPER_DIR}/Tools/RunTargetUnitTests:0: note: Skipped tests for ${1}"
}

if [ "${TEST_AFTER_BUILD}" = "YES" ]; then
    # Run the unit tests once per requested and supported architecture.
    for TEST_ARCH in ${ARCHS}; do
        case "${NATIVE_ARCH_ACTUAL}" in
        i386)
            if [ "${TEST_ARCH}" = "i386" ]; then
                RunTargetUnitTestsForArch "${TEST_ARCH}"
            else
                SkipTargetUnitTestsForArch "${TEST_ARCH}"
            fi
            ;;

        x86_64)
            if [ "${TEST_ARCH}" = "i386" -o "${TEST_ARCH}" = "x86_64" ]; then
                RunTargetUnitTestsForArch "${TEST_ARCH}"
            else
                SkipTargetUnitTestsForArch "${TEST_ARCH}"
            fi
            ;;

        *)
            RunTargetUnitTestsForArch "${TEST_ARCH}"
            ;;
        esac
    done
fi