XP Framework: Patch for issue #30

issue30.diff

diff --git a/core/src/main/php/unittest/AssertionFailedError.class.php b/core/src/main/php/unittest/AssertionFailedError.class.php
index e4e706c..a6d9377 100644
--- a/core/src/main/php/unittest/AssertionFailedError.class.php
+++ b/core/src/main/php/unittest/AssertionFailedError.class.php
@@ -7,7 +7,7 @@
   /**
    * Indicates an assertion failed
    *
-   * @purpose  Exception
+   * @test    xp://net.xp_framework.unittest.tests.StringComparisonTest
    */
   class AssertionFailedError extends XPException {
     public
@@ -29,18 +29,61 @@
     }
 
     /**
+     * Format the difference between the expected and actual values
+     *
+     * @return  string
+     */
+    public function formatDifference() {
+      if (is_string($this->expect) && is_string($this->actual)) {
+        $la= strlen($this->actual);
+        $le= strlen($this->expect);
+        for ($i= 0, $l= min($le, $la); $i < $l; $i++) {                     // Search from beginning
+          if ($this->expect{$i} !== $this->actual{$i}) break;
+        }
+        for ($j= $le- 1, $k= $la- 1; $k >= $i && $j >= $i; $k--, $j--) {    // Search from end
+          if ($this->expect{$j} !== $this->actual{$k}) break;
+        }
+        if ($j < $i && $k < $i) {
+          $expect= '"'.$this->expect.'"';
+          $actual= '"'.$this->actual.'"';
+        } else {
+          $expect= substr($this->expect, $i, $j+ 1- $i);
+          $actual= substr($this->actual, $i, $k+ 1- $i);
+          $c= $i <= $l && $i > 0;
+          $expect= $c ? '"...'.$expect : '"'.$expect;                       // Common beginning
+          $actual= $c ? '"...'.$actual : '"'.$actual;
+          $expect.= ($j < $le- 1) ? '..."' : '"';                           // Common ending
+          $actual.= ($k < $la- 1) ? '..."' : '"';
+        }
+      } else {
+        $ta= typeof($this->actual);
+        $te= typeof($this->expect);
+        if ($ta->equals($te)) {
+          $expect= xp::stringOf($this->expect);
+          $actual= xp::stringOf($this->actual);
+        } else {
+          if ($te instanceof XPClass) {
+            $expect= $this->expect->toString();
+          } else {
+            $expect= NULL == $this->expect ? 'null' : $te->getName().'<'.xp::stringOf($this->expect).'>';
+          }
+          if ($ta instanceof XPClass) {
+            $actual= $this->actual->toString();
+          } else {
+            $actual= NULL == $this->actual ? 'null' : $ta->getName().'<'.xp::stringOf($this->actual).'>';
+          }
+        }
+      }
+      return 'expected: '.$expect.' but was: '.$actual;
+    }
+
+    /**
      * Return compound message of this exception.
      *
      * @return  string
      */
     public function compoundMessage() {
-      return sprintf(
-        "%s (%s) { expected: [%s:%s] but was: [%s:%s] }\n",
-        $this->getClassName(),
-        $this->message,
-        xp::typeOf($this->expect), xp::stringOf($this->expect),
-        xp::typeOf($this->actual), xp::stringOf($this->actual)
-      );
+      return $this->getClassName().' ('.$this->message.') { '.$this->formatDifference().' }';
     }
     
     /**
diff --git a/core/src/resources/unittest/unittest.ini b/core/src/resources/unittest/unittest.ini
index be6b518..18e93cf 100644
--- a/core/src/resources/unittest/unittest.ini
+++ b/core/src/resources/unittest/unittest.ini
@@ -29,3 +29,6 @@ class="net.xp_framework.unittest.tests.WebTestCaseTest"
 
 [special]
 class="net.xp_framework.unittest.tests.SpecialMethodsTest"
+
+[comparison]
+class="net.xp_framework.unittest.tests.ComparisonTest"
diff --git a/core/src/test/php/net/xp_framework/unittest/tests/ComparisonTest.class.php b/core/src/test/php/net/xp_framework/unittest/tests/ComparisonTest.class.php
new file mode 100644
index 0000000..4054b0d
--- /dev/null
+++ b/core/src/test/php/net/xp_framework/unittest/tests/ComparisonTest.class.php
@@ -0,0 +1,177 @@
+<?php
+/* This class is part of the XP framework
+ *
+ * $Id$
+ */
+
+  uses('unittest.TestCase');
+
+  /**
+   * TestCase
+   *
+   * @see   xp://unittest.AssertionFailedError
+   */
+  class ComparisonTest extends TestCase {
+
+    /**
+     * Helper method
+     *
+     * @param   var expected
+     * @param   var actual
+     * @return  string
+     */
+    protected function compare($expected, $actual) {
+      return create(new AssertionFailedError('', $actual, $expected))->formatDifference();
+    }
+
+    /**
+     * Test strings
+     *
+     */
+    #[@test]
+    public function stringWithCommonBeginning() {
+      $prefix= str_repeat('0123456789', 10);
+
+      $this->assertEquals(
+        'expected: "...3abc" but was: "...Hello Worlddef"',
+        $this->compare($prefix.'3abc', $prefix.'Hello Worlddef')
+      );
+    }
+
+    /**
+     * Test strings
+     *
+     */
+    #[@test]
+    public function stringWithCommonEnding() {
+      $postfix= str_repeat('012345678', 10);
+
+      $this->assertEquals(
+        'expected: "3..." but was: "Hello World..."',
+        $this->compare('3'.$postfix, 'Hello World'.$postfix)
+      );
+    }
+
+    /**
+     * Test strings
+     *
+     */
+    #[@test]
+    public function stringWithCommonBeginningAndEnding() {
+      $prefix= str_repeat('0123456789', 10);
+      $postfix= str_repeat('012345678', 10);
+
+      $this->assertEquals(
+        'expected: "...3..." but was: "...Hello World..."',
+        $this->compare($prefix.'3'.$postfix, $prefix.'Hello World'.$postfix)
+      );
+    }
+
+    /**
+     * Test two strings
+     *
+     */
+    #[@test]
+    public function twoStrings() {
+      $this->assertEquals(
+        'expected: "Hello" but was: "World"',
+        $this->compare('Hello', 'World')
+      );
+    }
+
+    /**
+     * Test two integers
+     *
+     */
+    #[@test]
+    public function twoIntegers() {
+      $this->assertEquals(
+        'expected: 3 but was: 1',
+        $this->compare(3, 1)
+      );
+    }
+
+    /**
+     * Test two doubles
+     *
+     */
+    #[@test]
+    public function twoDoubles() {
+      $this->assertEquals(
+        'expected: 3.1 but was: 1.1',
+        $this->compare(3.1, 1.1)
+      );
+    }
+
+    /**
+     * Test two bools
+     *
+     */
+    #[@test]
+    public function twoBools() {
+      $this->assertEquals(
+        'expected: true but was: false',
+        $this->compare(TRUE, FALSE)
+      );
+    }
+
+    /**
+     * Test two integer arrays
+     *
+     */
+    #[@test]
+    public function twoArrays() {
+      $this->assertEquals(
+        "expected: [\n  0 => 1\n  1 => 2\n] but was: [\n  0 => 2\n  1 => 3\n]",
+        $this->compare(array(1, 2), array(2, 3))
+      );
+    }
+
+    /**
+     * Test string vs null
+     *
+     */
+    #[@test]
+    public function twoObjects() {
+      $this->assertEquals(
+        'expected: unittest.TestCase<a> but was: unittest.TestCase<b>',
+        $this->compare(new TestCase('a'), new TestCase('b'))
+      );
+    }
+    /**
+     * Test string vs int
+     *
+     */
+    #[@test]
+    public function stringVsInt() {
+      $this->assertEquals(
+        'expected: string<"3"> but was: int<3>',
+        $this->compare('3', 3)
+      );
+    }
+
+    /**
+     * Test string vs double
+     *
+     */
+    #[@test]
+    public function stringVsDouble() {
+      $this->assertEquals(
+        'expected: string<"3"> but was: double<3>',
+        $this->compare('3', 3.0)
+      );
+    }
+
+    /**
+     * Test string vs null
+     *
+     */
+    #[@test]
+    public function stringVsNull() {
+      $this->assertEquals(
+        'expected: string<"null"> but was: null',
+        $this->compare('null', NULL)
+      );
+    }
+  }
+?>

What the formatDifference() method does:

• If actual and expected are strings, applies an algorithm to show only difference
• If actual and expected are of the same type, show their string representations
• Otherwise:
  • For objects, show their toString output
  • For null, show the string "null" (without quotes)
  • For anything else, show the type name and string representation