1 files changed, 42 insertions, 0 deletions
diff --git a/sangria-test/src/main/java/com/tavianator/sangria/test/BestPracticesMatcher.java b/sangria-test/src/main/java/com/tavianator/sangria/test/BestPracticesMatcher.java
new file mode 100644
index 0000000..36eea97
--- /dev/null
+++ b/sangria-test/src/main/java/com/tavianator/sangria/test/BestPracticesMatcher.java
@@ -0,0 +1,42 @@
+package com.tavianator.sangria.test;
+
+import com.google.inject.AbstractModule;
+import com.google.inject.CreationException;
+import com.google.inject.Guice;
+import com.google.inject.Module;
+import org.hamcrest.Description;
+import org.hamcrest.TypeSafeDiagnosingMatcher;
+
+/**
+ * Matcher that checks whether a {@link Module} follows Guice best practices.
+ *
+ * @author Tavian Barnes (tavianator@tavianator.com)
+ * @version 1.2
+ * @since 1.2
+ */
+final class BestPracticesMatcher extends TypeSafeDiagnosingMatcher<Module> {
+    private static final class EnforcerModule extends AbstractModule {
+        @Override
+        protected void configure() {
+            binder().requireAtInjectOnConstructors();
+            binder().requireExactBindingAnnotations();
+            binder().requireExplicitBindings();
+        }
+    }
+
+    @Override
+    protected boolean matchesSafely(Module item, Description mismatchDescription) {
+        try {
+            Guice.createInjector(item, new EnforcerModule());
+            return true;
+        } catch (CreationException e) {
+            mismatchDescription.appendValue(e);
+            return false;
+        }
+    }
+
+    @Override
+    public void describeTo(Description description) {
+        description.appendText("a Module following Guice best practices");
+    }
+}