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11 | <title>A testing system for Boost.Build</title> |
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26 | <body> |
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27 | <p><a href="../../../../index.htm"><img class="banner" height="86" width= |
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28 | "277" alt="C++ Boost" src="../../../../boost.png"></a></p> |
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29 | |
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30 | <h1>A testing system for Boost.Build<br class="clear"> |
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31 | </h1> |
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32 | <hr> |
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33 | |
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34 | <dl class="page-index"> |
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35 | <dt><a href="#sec-intro">Introduction for users</a></dt> |
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36 | |
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37 | <dt><a href="#sec-developers">Introduction for developers</a></dt> |
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38 | |
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39 | <dd> |
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40 | <dl class="page-index"> |
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41 | <dt><a href="#sec-intro-changing">Changing the working |
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42 | directory</a></dt> |
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43 | |
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44 | <dt><a href="#sec-intro-examining">Examining the working directory |
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45 | and changing it</a></dt> |
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46 | |
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47 | <dt><a href="#sec-intro-results">Test result</a></dt> |
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48 | </dl> |
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49 | </dd> |
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50 | |
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51 | <dt><a href="#sec-reference">Reference documentation</a></dt> |
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52 | |
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53 | <dd> |
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54 | <dl class="page-index"> |
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55 | <dt><a href="#method-__init__">Method __init__</a></dt> |
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56 | |
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57 | <dt><a href="#method-set_tree">Method <tt>set_tree</tt></a></dt> |
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58 | |
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59 | <dt><a href="#method-write">Method <tt>write</tt></a></dt> |
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60 | |
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61 | <dt><a href="#method-copy">Method <tt>copy</tt></a></dt> |
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62 | |
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63 | <dt><a href="#method-touch">Method <tt>touch</tt></a></dt> |
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64 | |
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65 | <dt><a href="#method-run_build_system">Method |
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66 | <tt>run_build_system</tt></a></dt> |
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67 | |
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68 | <dt><a href="#method-read">Method <tt>read</tt></a></dt> |
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69 | |
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70 | <dt><a href="#method-read_and_strip">Method |
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71 | <tt>read_and_strip</tt></a></dt> |
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72 | |
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73 | <dt><a href="#methods-expectations">Methods for declaring |
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74 | expectations</a></dt> |
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75 | |
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76 | <dt><a href="#methods-ignoring">Methods for ignoring |
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77 | changes</a></dt> |
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78 | |
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79 | <dt><a href="#methods-result">Methods for explicitly specifying |
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80 | results</a></dt> |
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81 | |
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82 | <dt><a href="#class-list">Helper class <tt>List</tt></a></dt> |
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83 | </dl> |
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84 | </dd> |
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85 | </dl> |
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86 | <hr> |
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87 | |
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88 | <h2><a name="sec-intro">Introduction for users</a></h2> |
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89 | |
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90 | <p>The testing system for Boost.Build is a small set of Python modules |
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91 | and scripts for automatically testing user-obversable behaviour. It uses |
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92 | components from testing systems of <a href= |
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93 | "http://www.scons.org">Scons</a> and <a href= |
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94 | "http://subversion.tigris.org">Subverion</a>, together with some |
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95 | additional functionality.</p> |
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96 | |
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97 | <p>To run the tests you'd need:</p> |
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98 | |
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99 | <ol> |
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100 | <li>Get the source tree of Boost.Build (located at <tt>tools/build</tt> |
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101 | in Boost)</li> |
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102 | |
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103 | <li>Have <a href="http://www.python.org">Python</a> installed. Version |
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104 | 2.1 is known to work.</li> |
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105 | |
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106 | <li>Build Boost.Jam. See <a href= |
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107 | "../../../jam/index.html">$boost_build_root/jam/index.html</a> for |
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108 | instructions.</li> |
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109 | |
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110 | <li>Configure at least one toolset. You can edit |
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111 | <tt>site-config.jam</tt> or <tt>user-config.jam</tt> to add new |
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112 | toolsets. Or you can create file <tt>test-config.jam</tt> in |
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113 | <tt>$boost_build_root/test</tt> directory. In this case, |
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114 | <tt>site-config.jam</tt> and <tt>user-config.jam</tt> will be ignored |
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115 | for testing.</li> |
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116 | </ol> |
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117 | |
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118 | <p>When all is done, you can run the tests with</p> |
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119 | <pre class="code"> |
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120 | python test_all.py |
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121 | </pre> |
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122 | |
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123 | <p>which will use the default toolset, or you can specify toolset on the |
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124 | command line, for example:</p> |
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125 | <pre class="code"> |
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126 | python test_all.py borland |
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127 | </pre> |
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128 | |
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129 | <p>If everything's OK, you'll see a list of passed tests. Otherwise, a |
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130 | failure will be reported.</p> |
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131 | |
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132 | <p>It is possible to run a specific test, for example:</p> |
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133 | <pre class="code"> |
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134 | python generators_test.py |
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135 | </pre> |
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136 | |
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137 | <h2><a name="sec-developers">Introduction for developers</a></h2> |
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138 | |
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139 | <p>It is suggested that every new functionality come together with tests, |
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140 | and that bugfixes are accompanied by tests. There's no need to say that |
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141 | tests are good, but two points are extremely important:</p> |
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142 | |
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143 | <ul> |
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144 | <li>For an interpreted language like Jam, without any static checks, |
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145 | testing is simply the only sefeguard we can have.</li> |
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146 | |
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147 | <li>Good tests allow to change internal design much more safely, and we |
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148 | didn't nailed everything down yet.</li> |
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149 | </ul> |
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150 | |
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151 | <p>Adding a new test is simple:</p> |
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152 | |
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153 | <ol> |
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154 | <li>Go to <tt>$boost_build_root/test/test_all.py</tt> and add new test |
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155 | name to the list at the end of file. Suppose the test name is |
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156 | "hello".</li> |
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157 | |
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158 | <li>Add a new python module, in this example "hello.py", to do actual |
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159 | testing.</li> |
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160 | </ol> |
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161 | |
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162 | <p>The module, in general will perform these basic actions:</p> |
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163 | |
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164 | <ol> |
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165 | <li>Setting the initial working directory state</li> |
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166 | |
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167 | <li> |
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168 | Running the build system and checking: |
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169 | |
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170 | <ol> |
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171 | <li>generated output,</li> |
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172 | |
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173 | <li>changes made to the working directory,</li> |
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174 | |
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175 | <li>new content of the working directory.</li> |
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176 | </ol> |
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177 | </li> |
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178 | |
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179 | <li>Adding, removing or touching files, or changing their content and |
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180 | then repeating the previous step, until satisfied.</li> |
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181 | |
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182 | <li>Cleaning up</li> |
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183 | </ol> |
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184 | |
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185 | <p>The "hello.py" module might contain:</p> |
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186 | <pre class="example"> |
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187 | from BoostBuild import Tester, List |
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188 | |
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189 | # Create a temporary working directory |
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190 | t = Tester() |
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191 | |
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192 | # Create the needed files |
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193 | t.write("project-root.jam", "") |
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194 | t.write("Jamfile", """ |
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195 | exe hello : hello.cpp ; |
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196 | """) |
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197 | t.write("hello.cpp", """ |
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198 | int main() |
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199 | { |
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200 | return 0; |
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201 | } |
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202 | |
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203 | """) |
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204 | |
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205 | t.run_build_system() |
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206 | |
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207 | # First, create a list of three pathnames |
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208 | file_list = List("bin/$toolset/debug/") * List("hello.exe hello.obj") |
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209 | # Second, assert that those files were added as result of the last build system invocation. |
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210 | t.expect_addition(file_list) |
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211 | |
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212 | # Invoke the build system once again |
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213 | t.run_build_system("clean") |
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214 | # Check if the files added previously were removed. |
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215 | t.expect_removal(file_list) |
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216 | |
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217 | # Remove temporary directories |
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218 | t.cleanup() |
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219 | </pre> |
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220 | |
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221 | <p>The <tt>test</tt> directory contains a file "template.py" which can be |
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222 | used as a start for your own tests.</p> |
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223 | |
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224 | <p>Overview of the most important methods of class |
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225 | <tt>TestBoostBuild</tt> follows.</p> |
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226 | |
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227 | <h3><a name="sec-intro-changing">Changing the working directory</a></h3> |
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228 | |
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229 | <p>The class <tt>TestBoostBuild</tt> creates a temporary directory in its |
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230 | constructor and changes to that directory. It can be modified by calling |
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231 | these methods:</p> |
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232 | |
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233 | <ul> |
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234 | <li><tt>set_tree</tt> -- sets the content of the working directory to |
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235 | be equal to the content of the specified directory. This method is |
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236 | preferrable when directory tree for testing is large.</li> |
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237 | |
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238 | <li><tt>write</tt> -- sets the content of file in a working directory. |
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239 | This is optimal if you want to create a directory tree with 3-4 small |
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240 | files.</li> |
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241 | |
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242 | <li><tt>touch</tt> -- changes the modification times of a file</li> |
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243 | </ul> |
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244 | |
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245 | <h3><a name="sec-intro-examining">Examining the working directory and |
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246 | changing it</a></h3> |
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247 | |
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248 | <p>The method <tt>read</tt>, inherited from the <tt>TestCmd</tt> class, |
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249 | can be used to read any file in the working directory and check its |
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250 | content. <tt>TestBoostBuild</tt> adds another method for tracking |
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251 | changes. Whenever build system is run (via <tt>run_build_system</tt>), |
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252 | the state of working dir before and after running is recorded. In |
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253 | addition, difference between the two states -- i.e. lists of files that |
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254 | were added, removed, modified or touched -- is stored in two member |
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255 | variables, <tt>tree_difference</tt> and |
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256 | <tt>unexpected_difference</tt>.</p> |
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257 | |
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258 | <p>After than, the test author may specify that some change is expected, |
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259 | for example, by calling <tt>expect_addition("foo")</tt>. This call will |
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260 | check if the file was indeed added, and if so, will remove its name from |
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261 | the list of added files in <tt>unexpected_difference</tt>. Likewise, it's |
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262 | possible to specify that some changes are not interesting, for example a |
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263 | call <tt>ignore("*.obj")</tt> will just remove every files with ".obj" |
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264 | extension from <tt>unexpected_difference</tt>.</p> |
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265 | |
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266 | <p>When test has finished with expectations and ignoring, the member |
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267 | <tt>unexpected_difference</tt> will contain the list of all changes not |
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268 | yet accounted for. It is possible to assure that this list is empty by |
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269 | calling <tt>expect_nothing_more</tt> member function.</p> |
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270 | |
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271 | <h3><a name="sec-intro-results">Test result</a></h3> |
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272 | |
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273 | <p>Any of the <tt>expect*</tt> methods below will fail the test if the |
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274 | expectation is not met. It is also possible to perform manually arbitrary |
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275 | test and explicitly cause the test to either pass or fail. Ordinary |
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276 | filesystem functions can be used to work with the directory tree. Methods |
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277 | <tt>pass_test</tt> and <tt>fail_test</tt> are used to explicitly give the |
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278 | test outcome.</p> |
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279 | |
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280 | <p>Typically, after test termination, the working directory is erased. To |
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281 | debug a failed test, you should add "--preserve" option when invoking |
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282 | test. On failure, the working directory will be copied to "failed_test" |
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283 | directory in the current dir.</p> |
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284 | |
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285 | <h2 id="sec-reference">Reference documentation</h2> |
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286 | |
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287 | <p>The test system is composed of class <tt>Tester</tt>, derived form |
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288 | <tt>TestCmd.TestCmd</tt>, and helper class <tt>List</tt>. The methods of |
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289 | <tt>Tester</tt>, and the class <tt>List</tt> are described below.</p> |
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290 | |
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291 | <p>The documentation frequently refer to filename. In all cases, files |
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292 | are specified in unix style: a sequence of components, separated by "/". |
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293 | This is true on all platforms. In some contexts, a list of files is |
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294 | allowed. In that case any object with sequence interface is allowed.</p> |
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295 | |
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296 | <h3><a name="method-__init__">Method <tt>__init__(self, workdir='', |
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297 | arguments='', executable='bjam')</tt></a></h3> |
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298 | |
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299 | <p><b>Effects:</b></p> |
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300 | |
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301 | <ol> |
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302 | <li>Remembers the current working directory in member |
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303 | <tt>original_workdir</tt>.</li> |
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304 | |
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305 | <li>Determines the location of executable (<code>bjam</code> by |
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306 | default) and build system files, assuming that the current directory is |
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307 | <tt>tools/build/test</tt>. Formulates jam invocation command, which |
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308 | will include explicit setting for <tt>BOOST_BUILD_PATH</tt> variable |
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309 | and arguments passed to this methods, if any. This command will be used |
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310 | by subsequent invocation of <a href= |
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311 | "#method-run_build_system"><tt>run_build_system</tt></a>. Finally, |
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312 | initializes the base class.</li> |
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313 | |
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314 | <li>Changes current working dir to the temporary working directory |
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315 | created by the base constructor.</li> |
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316 | |
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317 | <li>If you want to run a test in a existing directory, pass it to |
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318 | <tt>workdir</tt>.</li> |
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319 | </ol> |
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320 | |
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321 | <h3><a name="method-set_tree">Method <tt>set_tree(self, |
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322 | tree_location)</tt></a></h3> |
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323 | |
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324 | <p><b>Effects:</b></p> |
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325 | |
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326 | <p>Replaces the content of the current working directory with the content |
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327 | of directory at <tt>tree_location</tt>. If <tt>tree_location</tt> is not |
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328 | absolute pathname, it will be treated as relative to |
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329 | <tt>self.original_workdir</tt>. This methods also explicitly makes the |
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330 | copied files writeable.</p> |
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331 | |
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332 | <h3><a name="method-write">Method <tt>write(self, name, |
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333 | content)</tt></a></h3> |
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334 | |
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335 | <p><b>Effects:</b></p> |
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336 | |
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337 | <p>Writes the specified content to the file given by <tt>name</tt> under |
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338 | the temporary working directory. If the file already exists, it is |
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339 | overwritten. Any required directories are automatically created.</p> |
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340 | |
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341 | <h3><a name="method-copy">Method <tt>copy(self, src, dst)</tt></a></h3> |
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342 | |
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343 | <p><b>Effects:</b></p> |
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344 | |
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345 | <p>Equvivalent to <tt>self.write(self.read(src), dst)</tt>.</p> |
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346 | |
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347 | <h3><a name="method-touch">Method <tt>touch(self, names)</tt></a></h3> |
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348 | |
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349 | <p><b>Effects:</b></p> |
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350 | |
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351 | <p>Sets the access and modification times for all files in <tt>names</tt> |
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352 | to the current time. All the elements in <tt>names</tt> should be |
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353 | relative paths.</p> |
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354 | |
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355 | <h3><a name="method-run_build_system">Method <tt>run_build_system(self, |
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356 | subdir='', extra_args='', stdout=None, stderr='', status=0, |
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357 | **kw)</tt></a></h3> |
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358 | |
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359 | <p><b>Effects:</b></p> |
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360 | |
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361 | <ol> |
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362 | <li>Stores the state of the working directory in |
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363 | <tt>self.previous_tree</tt>.</li> |
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364 | |
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365 | <li>Changes to <tt>subdir</tt>, if it is specified. It is relative to |
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366 | the <tt>original_workdir</tt> or the workdir specified in |
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367 | <tt>__init</tt>.</li> |
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368 | |
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369 | <li>Invokes the <tt>bjam</tt> executable, passing <tt>extra_args</tt> |
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370 | to it. The binary should be located under |
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371 | <tt><test_invocation_dir>/../jam/src/bin.<platform></tt>. |
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372 | This is to make sure tests use the version of jam build from CVS.</li> |
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373 | |
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374 | <li>Compares the stdout, stderr and exit status of build system |
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375 | invocation with values to appropriate parameters, if they are not |
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376 | <tt>None</tt>. If any difference is found, the test fails.</li> |
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377 | |
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378 | <li> |
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379 | <p>Stores the new state of the working directory in |
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380 | <tt>self.tree</tt>. Computes the difference between previous and |
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381 | current trees and store them in variables |
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382 | <tt>self.tree_difference</tt> and |
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383 | <tt>self.unexpected_difference</tt>.</p> |
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384 | |
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385 | <p>Both variables are instances of class |
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386 | <tt>tree.Trees_different</tt>, which have four attributes: |
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387 | <tt>added_files</tt>, <tt>removed_files</tt>, <tt>modified_files</tt> |
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388 | and <tt>touched_files</tt>. Each is a list of strings.</p> |
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389 | </li> |
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390 | </ol> |
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391 | |
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392 | <h3><a name="method-read">Method <tt>read(self, name)</tt></a></h3> |
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393 | |
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394 | <p><b>Effects:</b></p> |
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395 | |
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396 | <p>Read the specified file and returns it content. Raises an exception is |
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397 | the file is absent.</p> |
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398 | |
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399 | <h3><a name="method-read_and_strip">Method <tt>read_and_strip(self, |
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400 | name)</tt></a></h3> |
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401 | |
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402 | <p><b>Effects:</b></p> |
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403 | |
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404 | <p>Read the specified file and returns it content, after removing |
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405 | trailing whitespace from every line. Raises an exception is the file is |
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406 | absent.</p> |
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407 | |
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408 | <p><b>Rationale:</b></p> |
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409 | |
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410 | <p>Althought this method is questionable, there are a lot of cases when |
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411 | jam or shells it uses insert spaces. It seems that introducing this |
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412 | method is much simpler than dealing with all those cases.</p> |
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413 | |
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414 | <h3><a name="methods-expectations">Methods for declaring |
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415 | expectations</a></h3> |
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416 | |
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417 | <p>Accordingly to the number of changes kinds that are detected, there |
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418 | are four methods that specify that test author expects a specific change |
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419 | to occur. They check <tt>self.unexpected_difference</tt>, and if the |
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420 | change is present there, it is removed. Otherwise, test fails.</p> |
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421 | |
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422 | <p>Each method accepts a list of names. Those names use <tt>/</tt> path |
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423 | separator on all systems. Additionaly, the test system translates |
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424 | suffixes appropriately. For the test to be portable, suffixes should use |
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425 | Windows convention: <tt>exe</tt> for executables, <tt>dll</tt> for |
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426 | dynamic libraries and <tt>lib</tt> for static libraries. Lastly, the |
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427 | string "$toolset" in file names is replaced by the name of tested |
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428 | toolset.</p> |
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429 | |
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430 | <p><b>Note:</b> The <tt>List</tt> helper class might be useful to create |
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431 | lists of names.</p> |
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432 | |
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433 | <p><b>Note:</b> The file content can be examined using |
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434 | <tt>TestCmd.read</tt> function.</p> |
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435 | |
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436 | <p>The members are:</p> |
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437 | |
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438 | <ul> |
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439 | <li>expect_addition</li> |
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440 | |
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441 | <li>expect_removal</li> |
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442 | |
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443 | <li>expect_modification</li> |
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444 | |
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445 | <li>expect_nothing</li> |
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446 | </ul> |
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447 | |
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448 | <p>Note that <tt>expect_modification</tt> is used to check that a either |
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449 | file content or timestamp has changed. The rationale is that some |
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450 | compilers change content even if sources does not change, and it's easier |
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451 | to have a method which checks for both content and time changes.</p> |
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452 | |
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453 | <p>There's also a member <tt>expect_nothing_more</tt>, which checks that |
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454 | all the changes are either expected or ignored, in other words that |
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455 | <tt>unexpected_difference</tt> is empty by now.</p> |
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456 | |
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457 | <p>Lastly, there's a method to compare file content with expected |
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458 | content:</p> |
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459 | <tt>expect_content(self, name, content, exact=0)</tt> |
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460 | |
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461 | <p>The method fails the test if the content of file identified by 'name' |
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462 | is different from 'content'. If 'exact' is true, the file content is used |
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463 | as-is, otherwise, two transformations are applied:</p> |
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464 | |
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465 | <ul> |
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466 | <li>The <tt>read_and_strip</tt> method is used to read the file, which |
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467 | removes trailing whitespace</li> |
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468 | |
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469 | <li>Each backslash in the file content is converted to forward |
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470 | slash.</li> |
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471 | </ul> |
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472 | |
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473 | <h3><a name="methods-ignoring">Methods for ignoring changes</a></h3> |
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474 | |
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475 | <p>There are five methods which ignore changes made to the working tree. |
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476 | They silently remove elements from <tt>self.unexpected_difference</tt>, |
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477 | and don't generate error if element is not found. They accept shell style |
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478 | wildcard.</p> |
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479 | |
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480 | <p>The following methods correspond to four kinds of changes:</p> |
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481 | |
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482 | <ul> |
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483 | <li>ignore_addition(self, wildcard)</li> |
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484 | |
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485 | <li>ignore_removal(self, wildcard)</li> |
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486 | |
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487 | <li>ignore_modification(self, wildcard)</li> |
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488 | |
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489 | <li>ignore_touch(self, wilcard)</li> |
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490 | </ul> |
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491 | |
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492 | <p>The method <tt>ignore(self, wildcard)</tt> ignores all the changes |
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493 | made to files that match a wildcard.</p> |
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494 | |
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495 | <h3><a name="methods-result">Methods for explicitly specifying |
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496 | results</a></h3> |
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497 | |
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498 | <h4>Method <tt>pass_test(self, condition=1)</tt></h4> |
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499 | |
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500 | <div class="attention"> |
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501 | At this moment, the method should not be used. |
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502 | </div> |
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503 | |
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504 | <h4>Method <tt>fail_test(self, condition=1)</tt></h4> |
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505 | |
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506 | <p><b>Effects:</b> Cause the test to fail if <tt>condition</tt> is |
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507 | true.</p> |
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508 | |
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509 | <h3><a name="class-list">Helper class <tt>List</tt></a></h3> |
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510 | The class has sequence interface and two additional methods. |
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511 | |
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512 | <h4>Method <tt>__init__(self, string)</tt></h4> |
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513 | |
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514 | <p><b>Effects:</b> Splits the string on unescaped spaces and tabs. The |
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515 | split components can further be retrieved using standard sequence |
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516 | access.</p> |
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517 | |
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518 | <h4>Method <tt>__mul__(self, other)</tt></h4> |
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519 | |
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520 | <p><b>Effects:</b> Returns an <tt>List</tt> instance, which elements are |
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521 | all possible concatenations of two string, first of which is from |
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522 | <tt>self</tt>, and second of which is from <tt>other</tt>.</p> |
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523 | |
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524 | <p>The class also defines <tt>__str__</tt> and <tt>__repr__</tt> methods. |
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525 | Finally, there's <tt>__coerce__</tt> method which allows to convert |
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526 | strings to instances of <tt>List</tt>.</p> |
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527 | |
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528 | <p><b>Example:</b></p> |
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529 | <pre> |
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530 | l = "a b" * List("c d") |
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531 | for e in l: |
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532 | print e |
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533 | |
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534 | </pre> |
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535 | |
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536 | <p>will output</p> |
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537 | <pre> |
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538 | ac |
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539 | ad |
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540 | bc |
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541 | bd |
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542 | |
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543 | </pre> |
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544 | <hr> |
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545 | |
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546 | <p class="revision">Last modified: Mar 11, 2005</p> |
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547 | |
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548 | <p>© Copyright Vladimir Prus 2002, 2003, 2004, 2005. Permission to |
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549 | copy, use, modify, sell and distribute this document is granted provided |
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550 | this copyright notice appears in all copies. This document is provided |
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551 | ``as is'' without express or implied warranty, and with no claim as to |
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552 | its suitability for any purpose.</p> |
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553 | </body> |
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554 | </html> |
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555 | |
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