1 files changed, 46 insertions, 0 deletions
diff --git a/src/main/java/org/junit/rules/ExpectedExceptionMatcherBuilder.java b/src/main/java/org/junit/rules/ExpectedExceptionMatcherBuilder.java
new file mode 100644
index 0000000..e7d94c4
--- /dev/null
+++ b/src/main/java/org/junit/rules/ExpectedExceptionMatcherBuilder.java
@@ -0,0 +1,46 @@
+package org.junit.rules;
+
+import static org.hamcrest.CoreMatchers.allOf;
+import static org.junit.matchers.JUnitMatchers.isThrowable;
+
+import java.util.ArrayList;
+import java.util.List;
+
+import org.hamcrest.Matcher;
+
+/**
+ * Builds special matcher used by {@link ExpectedException}.
+ */
+class ExpectedExceptionMatcherBuilder {
+
+    private final List<Matcher<?>> matchers = new ArrayList<Matcher<?>>();
+
+    void add(Matcher<?> matcher) {
+        matchers.add(matcher);
+    }
+
+    boolean expectsThrowable() {
+        return !matchers.isEmpty();
+    }
+
+    Matcher<Throwable> build() {
+        return isThrowable(allOfTheMatchers());
+    }
+
+    private Matcher<Throwable> allOfTheMatchers() {
+        if (matchers.size() == 1) {
+            return cast(matchers.get(0));
+        }
+        return allOf(castedMatchers());
+    }
+
+    @SuppressWarnings({"unchecked", "rawtypes"})
+    private List<Matcher<? super Throwable>> castedMatchers() {
+        return new ArrayList<Matcher<? super Throwable>>((List) matchers);
+    }
+
+    @SuppressWarnings("unchecked")
+    private Matcher<Throwable> cast(Matcher<?> singleMatcher) {
+        return (Matcher<Throwable>) singleMatcher;
+    }
+}