Fix odd null pointer in module detection (#732)

* fix odd nullpointer

* Update ExternalProvider.java

Author: SentryMan

inject-generator/src/main/java/io/avaje/inject/generator/ExternalProvider.java

@@ -19,6 +19,7 @@
 import java.util.TreeSet;
 import java.util.stream.Stream;
 
+import javax.lang.model.element.Element;
 import javax.lang.model.element.ElementKind;
 import javax.lang.model.element.Modifier;
 import javax.lang.model.element.ModuleElement;
@@ -295,8 +296,8 @@ private static Stream<TypeElement> injectExtensions() {
 
     final var checkEnclosing =
       allModules.stream()
-        .flatMap(m -> m.getEnclosedElements().stream())
-        .flatMap(p -> p.getEnclosedElements().stream())
+        .flatMap(ExternalProvider::getEnclosed)
+        .flatMap(ExternalProvider::getEnclosed)
         .map(TypeElement.class::cast)
         .filter(t -> t.getKind() == ElementKind.CLASS)
         .filter(t -> t.getModifiers().contains(Modifier.PUBLIC))
@@ -311,6 +312,15 @@ private static Stream<TypeElement> injectExtensions() {
     return Stream.concat(checkEnclosing, checkDirectives);
   }
 
+  // when a project's module-info is misconfigured a certain way, getEnclosedElements throws an error
+  private static Stream<? extends Element> getEnclosed(Element e) {
+    try {
+      return e.getEnclosedElements().stream();
+    } catch (Exception ex) {
+      return Stream.of();
+    }
+  }
+
   private static boolean isInjectExtension(ModuleElement.ProvidesDirective p) {
     return "io.avaje.inject.spi.InjectExtension".equals(p.getService().getQualifiedName().toString());
   }