<fail> accepts nested conditions.

PR: 19220


git-svn-id: https://svn.apache.org/repos/asf/ant/core/trunk@276425 13f79535-47bb-0310-9956-ffa450edef68

WHATSNEW

@@ -34,6 +34,8 @@ Other changes:
 
 * <loadproperties> supports loading from a resource.
 
+* <fail> accepts nested conditions.
+
 Changes from Ant 1.6.1 to current Ant 1.6 CVS version
 =============================================
 

docs/manual/CoreTasks/fail.html

@@ -37,6 +37,16 @@ or character data nested into the element.</p>
     <td align="center" valign="top">No</td>
   </tr>
 </table>
+
+<h3>Parameters specified as nested elements</h3>
+
+<p>As an alternative to the <i>if</i>/<i>unless</i> attributes,
+  conditional failure can be achieved using a single nested condition.
+  For a complete list of core conditions, as well as information
+  about custom conditions, see <a href="conditions.html">here</a>.<br />
+  <b>Since Ant 1.6.2</b>
+</p>
+
 <h3>Examples</h3>
 <pre>  &lt;fail/&gt;</pre>
 <p>will exit the current build with no further information given.</p>
@@ -47,8 +57,9 @@ build.xml:4: No message
 </pre>
 
 <pre>  &lt;fail message=&quot;Something wrong here.&quot;/&gt;</pre>
-<p>will exit the current build and print something like the following to wherever
-your output goes:</p>
+<p>will exit the current build and print something
+  like the following to wherever your output goes:
+</p>
 <pre>
 BUILD FAILED
 
@@ -58,6 +69,32 @@ build.xml:4: Something wrong here.
 <pre>  &lt;fail&gt;Something wrong here.&lt;/fail&gt;</pre>
 <p>will give the same result as above.</p>
 
+<pre>  &lt;fail unless=&quot;thisdoesnotexist&quot;/&gt;</pre>
+<p>will exit the current build and print something
+  like the following to wherever your output goes:
+</p>
+<pre>
+BUILD FAILED
+
+build.xml:2: unless=thisdoesnotexist
+</pre>
+
+A simple example using conditions to achieve the same effect:
+<pre>
+  &lt;fail&gt;
+     &lt;not&gt;
+       &lt;isset property=&quot;thisdoesnotexist&quot;/&gt;
+     &lt;/not&gt;
+   &lt;/fail&gt;
+</pre>
+
+<p>Output:</p>
+<pre>
+BUILD FAILED
+
+build.xml:2: condition satisfied
+</pre>
+
 <hr>
 <p align="center">Copyright &copy; 2000-2001,2004 The Apache Software Foundation. All rights
 Reserved.</p>

src/etc/testcases/taskdefs/fail.xml

@@ -25,5 +25,57 @@
   <target name="testIfAndUnless">
     <fail unless="unless" if="if"/>
   </target>
+  
+  <target name="testNested1" description="should fail with default message">
+    <fail>
+      <and />
+    </fail>
+  </target>
+
+  <target name="testNested2" description="should pass">
+    <fail>
+      <or />
+    </fail>
+  </target>
+
+  <target name="testNested3" description="should fail">
+    <fail message="testNested3">
+      <and />
+    </fail>
+  </target>
+
+  <target name="testNested4a" description="should error">
+    <fail if="if">
+      <and />
+    </fail>
+  </target>
+
+  <target name="testNested4b" description="should error">
+    <fail unless="unless">
+      <and />
+    </fail>
+  </target>
+
+  <target name="testNested4c" description="should error">
+    <fail if="if" unless="unless">
+      <and />
+    </fail>
+  </target>
+
+  <target name="testNested5" description="should error">
+    <fail>
+      <and />
+      <or />
+    </fail>
+  </target>
+
+  <target name="testNested6" description="should fail with message">
+    <fail>
+      <and />
+testNested6
+testNested6
+testNested6
+    </fail>
+  </target>
 
 </project>

src/main/org/apache/tools/ant/taskdefs/Exit.java

@@ -18,8 +18,8 @@
 package org.apache.tools.ant.taskdefs;
 
 import org.apache.tools.ant.BuildException;
-import org.apache.tools.ant.Task;
-
+import org.apache.tools.ant.taskdefs.condition.Condition;
+import org.apache.tools.ant.taskdefs.condition.ConditionBase;
 
 /**
  * Exits the active build, giving an additional message
@@ -34,11 +34,15 @@ import org.apache.tools.ant.Task;
  * are true. i.e.
  * <pre>fail := defined(ifProperty) && !defined(unlessProperty)</pre>
  *
+ * A single nested<CODE>&lt;condition&gt;</CODE> element can be specified
+ * instead of using <CODE>if</CODE>/<CODE>unless</CODE> (a combined
+ * effect can be achieved using <CODE>isset</CODE> conditions).
+ *
  * @since Ant 1.2
  *
  * @ant.task name="fail" category="control"
  */
-public class Exit extends Task {
+public class Exit extends ConditionBase {
     private String message;
     private String ifCondition, unlessCondition;
 
@@ -69,31 +73,40 @@ public class Exit extends Task {
     }
 
     /**
-     * evaluate both if and unless conditions, and if
-     * ifCondition is true or unlessCondition is false, throw a
-     * build exception to exit the build.
-     * The error message is constructed from the text fields, or from
+     * Throw a <CODE>BuildException</CODE> to exit (fail) the build.
+     * If specified, evaluate conditions:
+     * A single nested condition is accepted, but requires that the
+     * <CODE>if</CODE>/<code>unless</code> attributes be omitted.
+     * If the nested condition evaluates to true, or the
+     * ifCondition is true or unlessCondition is false, the build will exit.
+     * The error message is constructed from the text fields, from
+     * the nested condition (if specified), or finally from
      * the if and unless parameters (if present).
      * @throws BuildException
      */
     public void execute() throws BuildException {
-        if (testIfCondition() && testUnlessCondition()) {
+        boolean fail = (nestedConditionPresent()) ? testNestedCondition()
+                     : (testIfCondition() && testUnlessCondition());
+        if (fail) {
             String text = null;
-            if (message != null && message.length() > 0) {
-                text = message;
+            if (message != null && message.trim().length() > 0) {
+                text = message.trim();
             } else {
-
-                if (getProject().getProperty(ifCondition) != null) {
+                if (ifCondition != null && ifCondition.length() > 0
+                    && getProject().getProperty(ifCondition) != null) {
                     text = "if=" + ifCondition;
                 }
                 if (unlessCondition != null && unlessCondition.length() > 0
-                        && getProject().getProperty(unlessCondition) == null) {
+                    && getProject().getProperty(unlessCondition) == null) {
                     if (text == null) {
                         text = "";
                     } else {
                         text += " and ";
                     }
                     text += "unless=" + unlessCondition;
+                }
+                if (nestedConditionPresent()) {
+                    text = "condition satisfied";
                 } else {
                     if (text == null) {
                         text = "No message";
@@ -138,4 +151,26 @@ public class Exit extends Task {
         return getProject().getProperty(unlessCondition) == null;
     }
 
+    /**
+     * test the nested condition
+     * @return true if there is none, or it evaluates to true
+     */
+    private boolean testNestedCondition() {
+        if (ifCondition != null || unlessCondition != null) {
+            throw new BuildException("Nested conditions "
+              + "not permitted in conjunction with if/unless attributes");
+        }
+
+        int count = countConditions();
+        if (count > 1) {
+            throw new BuildException("Too many conditions:  " + count);
+        }
+
+        return (count == 0) ? true
+            : (((Condition)(getConditions().nextElement())).eval());
+    }
+
+    private boolean nestedConditionPresent() {
+        return (countConditions() > 0);
+    }
 }

src/testcases/org/apache/tools/ant/taskdefs/FailTest.java

@@ -101,4 +101,50 @@ public class FailTest extends BuildFileTest {
         }
     }
 
-}
+    public void testNested1() {
+        expectSpecificBuildException("testNested1",
+            "it is required to fail :-)",
+            "condition satisfied");
+    }
+
+    public void testNested2() {
+        try {
+            executeTarget("testNested2");
+        } catch (BuildException be) {
+            fail("condition not satisfied; testNested2 must not fail");
+        }
+    }
+
+    public void testNested3() {
+        expectSpecificBuildException("testNested3",
+            "it is required to fail :-)",
+            "testNested3");
+    }
+
+    public void testNested4() {
+        String specificMessage = "Nested conditions "
+          + "not permitted in conjunction with if/unless attributes";
+
+        char[] c = {'a', 'b', 'c'};
+        StringBuffer target = new StringBuffer("testNested4x");
+
+        for (int i = 0; i < c.length; i++) {
+            target.setCharAt(target.length() - 1, c[i]);
+            expectSpecificBuildException(target.toString(),
+                "it is required to fail :-)", specificMessage);
+        }
+    }
+
+    public void testNested5() {
+        expectSpecificBuildException("testNested5",
+            "it is required to fail :-)",
+            "Too many conditions:  2");
+    }
+
+    public void testNested6() {
+        expectSpecificBuildException("testNested6",
+            "it is required to fail :-)",
+            "testNested6\ntestNested6\ntestNested6");
+    }
+
+ }