Subversion Repositories bacoAlunos

Rev

Details | Last modification | View Log | RSS feed

Rev Author Line No. Line
1777 jmachado 1 
<html>
2 
<head>
3 
<META http-equiv="Content-Type" content="text/html; charset=ISO-8859-1">
4 
<title>
5 
Assert Task</title>
6 
<meta content="DocBook XSL Stylesheets V1.60.1" name="generator">
7 
<link rel="home" href="index.html" title="Antelope Users Guide">
8 
<link rel="up" href="bk03.html" title="Additional Ant Tasks">
9 
<link rel="previous" href="bk03ch03.html" title="Chapter&nbsp;3.&nbsp;Installation">
10 
<link rel="next" href="bk03ch05.html" title="Chapter&nbsp;5.&nbsp;If Task">
11 
</head>
12 
<body bgcolor="white" text="black" link="#0000FF" vlink="#840084" alink="#0000FF">
13 
<div class="chapter" lang="en">
14 
<div class="titlepage">
15 
<div>
16 
<div>
17 
<h2 class="title">
18 
<a name="Assert">
19 
</a>
20 
Assert Task</h2>
21 
</div>
22 
</div>
23 
<div>
24 
</div>
25 
</div>
26 
<p>
27 
 
28 
The Assert task adds an assertion capability to Ant projects. This task works in a manner very similar to the Java <tt class="computeroutput">
29 
assert</tt>
30 
 keyword, and provides a limited "design by contract" facility to Ant. This is very useful for testing build scripts prior to putting them into production.
31 
</p>
32 
<p>
33 
 
34 
The Assert task verifies that a given property has a
35 
given value and throws a BuildException if the property value is not as expected
36 
or the property does not exist.
37 
</p>
38 
<p>
39 
 
40 
Also like Java's <tt class="computeroutput">
41 
assert</tt>
42 
 keyword, the Assert task must be 'turned on' using the property <tt class="computeroutput">
43 
ant.enable.asserts</tt>
44 
. If not set, or is set to <tt class="computeroutput">
45 
false</tt>
46 
, the Assert task works exactly like the Sequential task. If the <a href="variable_task.html" title="Variable Task">
47 
Variable task</a>
48 
 is used to define this property, then it can be turned on and off as needed throughout a build.
49 
</p>
50 
<p>
51 
 
52 
This task can hold other tasks including Assert.
53 
</p>
54 
<p>
55 
 
56 
The Assert task may contain one 'bool' element. The 'bool' element is identical to the ConditionTask, but unlike the ConditionTask, is actually a Task. The 'bool' element can contain all the conditions permitted by the ConditionTask, plus the <a href="bk03ch05s02.html" title="More Conditions">
57 
IsPropertyTrue</a>
58 
, <a href="more_conditions.html" title="More Conditions">
59 
IsPropertyFalse</a>
60 
,
61 
<a href="more_conditions.html" title="More Conditions">
62 
StartsWith</a>
63 
,
64 
<a href="more_conditions.html" title="More Conditions">
65 
EndsWith</a>
66 
,
67 
<a href="more_conditions.html" title="More Conditions">
68 
IsGreaterThan</a>
69 
,
70 
<a href="more_conditions.html" title="More Conditions">
71 
IsLessThan</a>
72 
 and conditions.
73 
See the If task for examples of using these conditionals.
74 
</p>
75 
 
76 
<p>
77 
 
78 
<div class="table">
79 
<a name="N10583">
80 
</a>
81 
<p class="title">
82 
<b>
83 
Table&nbsp;4.1.&nbsp;Assert Task Attributes</b>
84 
</p>
85 
<table summary="Assert Task Attributes" border="1">
86 
<colgroup>
87 
<col>
88 
<col>
89 
<col>
90 
<col>
91 
</colgroup>
92 
<thead>
93 
<tr>
94 
<th>
95 
Attribute</th>
96 
<th>
97 
Description</th>
98 
<th>
99 
Default</th>
100 
<th>
101 
Required</th>
102 
</tr>
103 
</thead>
104 
<tbody>
105 
<tr>
106 
<td>
107 
name</td>
108 
<td>
109 
The name of the property to test for.</td>
110 
<td>
111 
none</td>
112 
<td>
113 
Yes</td>
114 
</tr>
115 
<tr>
116 
<td>
117 
exists</td>
118 
<td>
119 
Test for existence or non-existence of the property.</td>
120 
<td>
121 
True</td>
122 
<td>
123 
No</td>
124 
</tr>
125 
<tr>
126 
<td>
127 
value</td>
128 
<td>
129 
The value to test for, implies 'exists=true'. If the value in the project is different than this value, a BuildException will be thrown and the build will stop.</td>
130 
<td>
131 
none</td>
132 
<td>
133 
No</td>
134 
</tr>
135 
<tr>
136 
<td>
137 
execute</td>
138 
<td>
139 
Should the tasks contained in this task be executed? It may be useful to set this to false when testing build files.</td>
140 
<td>
141 
True</td>
142 
<td>
143 
No</td>
144 
</tr>
145 
<tr>
146 
<td>
147 
failonerror</td>
148 
<td>
149 
Should the build halt if the assertion fails? Setting this to false is contrary to the intented use of assertions, but may be useful in certain situations. </td>
150 
<td>
151 
True</td>
152 
<td>
153 
No</td>
154 
</tr>
155 
</tbody>
156 
</table>
157 
</div>
158 
 
159 
 
160 
</p>
161 
<p>
162 
 
163 
As stated above, the Assert task may contain a nested "bool" task, otherwise,
164 
the Assert task does not support any nested
165 
elements apart from Ant tasks. Any valid Ant task may be embedded within the
166 
assert task.
167 
</p>
168 
<p>
169 
 
170 
In the following example, the first <tt class="computeroutput">
171 
assert</tt>
172 
 task checks that the <tt class="computeroutput">
173 
wait</tt>
174 
 property exists and does not execute the <tt class="computeroutput">
175 
echo</tt>
176 
 and <tt class="computeroutput">
177 
sleep</tt>
178 
 tasks. The second <tt class="computeroutput">
179 
assert</tt>
180 
 task checks that the <tt class="computeroutput">
181 
wait</tt>
182 
 property exists, has a value of 2, and executes the <tt class="computeroutput">
183 
echo</tt>
184 
 task.
185 
</p>
186 
<p>
187 
 
188 
<table border="0" bgcolor="#E0E0E0">
189 
<tr>
190 
<td>
191 
<pre class="programlisting">
192 
 
193 
 
194 
     &lt;property name="wait" value="2"/&gt;
195 
     &lt;assert name="wait" execute="false"&gt;
196 
        &lt;echo&gt;
197 
            Waiting ${wait} seconds...
198 
            Click the red button to stop waiting.
199 
        &lt;/echo&gt;
200 
        &lt;sleep seconds="${wait}"/&gt;
201 
     &lt;/assert&gt;
202 
     &lt;assert name="wait" value="2" execute="true"&gt;
203 
        &lt;echo&gt;done waiting!&lt;/echo&gt;
204 
     &lt;/assert&gt;
205 
 
206 
</pre>
207 
</td>
208 
</tr>
209 
</table>
210 
 
211 
</p>
212 
<p>
213 
 
214 
The next example shows Assert being used in a unit test for the "limit" task:
215 
<table border="0" bgcolor="#E0E0E0">
216 
<tr>
217 
<td>
218 
<pre class="programlisting">
219 
 
220 
 
221 
  &lt;property name="ant.enable.asserts" value="true"/&gt;
222 
  &lt;target name="test2"&gt;
223 
    &lt;!-- should not stop 'sleep' task, should print out '_passed_' --&gt;
224 
    &lt;stopwatch name="timer"/&gt;
225 
    &lt;limit maxwait="5"&gt;
226 
        &lt;sleep seconds="1"/&gt;
227 
        &lt;echo&gt;_passed_&lt;/echo&gt;
228 
    &lt;/limit&gt;
229 
    &lt;stopwatch name="timer" action="total"/&gt;
230 
    &lt;assert message="Too much time."&gt;
231 
        &lt;bool&gt;
232 
            &lt;islessthan arg1="${timer}" arg2="2"/&gt;
233 
        &lt;/bool&gt;
234 
    &lt;/assert&gt;
235 
  &lt;/target&gt;
236 
 
237 
</pre>
238 
</td>
239 
</tr>
240 
</table>
241 
 
242 
</p>
243 
<p>
244 
 
245 
If the <tt class="computeroutput">
246 
ant.enable.asserts</tt>
247 
 property is set to false, then in the above example, the <tt class="computeroutput">
248 
echo</tt>
249 
, <tt class="computeroutput">
250 
sleep</tt>
251 
, and <tt class="computeroutput">
252 
echo</tt>
253 
 tasks will all execute.
254 
</p>
255 
    <hr>
256 
    <p align="center">Copyright &copy; 2003 Ant-Contrib Project. All
257 
    rights Reserved.</p>
258 
</div>
259 
</body>
260 
</html>