1 files changed, 68 insertions, 0 deletions
diff --git a/tests/021-string2/src/junit/framework/ComparisonFailure.java b/tests/021-string2/src/junit/framework/ComparisonFailure.java
new file mode 100644
index 0000000..0cb2cee
--- /dev/null
+++ b/tests/021-string2/src/junit/framework/ComparisonFailure.java
@@ -0,0 +1,68 @@
+package junit.framework;
+
+/**
+ * Thrown when an assert equals for Strings failed.
+ *
+ * Inspired by a patch from Alex Chaffee mailto:alex@purpletech.com
+ */
+public class ComparisonFailure extends AssertionFailedError {
+    private String fExpected;
+    private String fActual;
+
+    /**
+     * Constructs a comparison failure.
+     * @param message the identifying message or null
+     * @param expected the expected string value
+     * @param actual the actual string value
+     */
+    public ComparisonFailure (String message, String expected, String actual) {
+        super (message);
+        fExpected= expected;
+        fActual= actual;
+    }
+
+    /**
+     * Returns "..." in place of common prefix and "..." in
+     * place of common suffix between expected and actual.
+     *
+     * @see java.lang.Throwable#getMessage()
+     */
+    public String getMessage() {
+        if (fExpected == null || fActual == null)
+            return Assert.format(super.getMessage(), fExpected, fActual);
+
+        int end= Math.min(fExpected.length(), fActual.length());
+
+        int i= 0;
+        for(; i < end; i++) {
+            if (fExpected.charAt(i) != fActual.charAt(i))
+                break;
+        }
+        int j= fExpected.length()-1;
+        int k= fActual.length()-1;
+        for (; k >= i && j >= i; k--,j--) {
+            if (fExpected.charAt(j) != fActual.charAt(k))
+                break;
+        }
+        String actual, expected;
+
+        // equal strings
+        if (j < i && k < i) {
+            expected= fExpected;
+            actual= fActual;
+        } else {
+            expected= fExpected.substring(i, j+1);
+            actual= fActual.substring(i, k+1);
+            if (i <= end && i > 0) {
+                expected= "..."+expected;
+                actual= "..."+actual;
+            }
+
+            if (j < fExpected.length()-1)
+                expected= expected+"...";
+            if (k < fActual.length()-1)
+                actual= actual+"...";
+        }
+        return Assert.format(super.getMessage(), expected, actual);
+    }
+}