Add resolve option for not throwing a resolveException

source/poodinis/container.d

@@ -70,7 +70,13 @@ public enum ResolveOption {
 	 * This essentially makes registration optional for resolving by concerete types.
 	 * Resolinvg will still fail when trying to resolve a dependency by supertype.
 	 */
-	registerBeforeResolving
+	registerBeforeResolving,
+
+	/**
+	 * Does not throw a resolve exception when a type is not registered but will
+	 * return null instead.
+	 */
+	noResolveException
 }
 
 /**
@@ -300,6 +306,10 @@ synchronized class DependencyContainer {
 
 		auto candidates = resolveType in registrations;
 		if (!candidates) {
+			if (hasOption(resolveOptions, persistentResolveOptions, ResolveOption.noResolveException)) {
+				return null;
+			}
+
 			throw new ResolveException("Type not registered.", resolveType);
 		}
 

test/poodinis/containertest.d

@@ -655,4 +655,11 @@ version(unittest) {
 		shared(DependencyContainer) container = new DependencyContainer();
 		assertThrown!ResolveException(container.resolve!TestInterface([ResolveOption.registerBeforeResolving]));
 	}
+
+	// Test ResolveOption noResolveException does not throw
+	unittest {
+		shared(DependencyContainer) container = new DependencyContainer();
+		auto instance = container.resolve!TestInterface([ResolveOption.noResolveException]);
+		assert(instance is null);
+	}
 }