From 86fb525066a99d87b883cff8d3b7ded66887b5d0 Mon Sep 17 00:00:00 2001
From: Mike Bierlee <m.bierlee@lostmoment.com>
Date: Sun, 11 Dec 2016 01:31:09 +0100
Subject: [PATCH] Add mandatory injection of values

---
 source/poodinis/autowire.d         |  3 +++
 source/poodinis/valueinjection.d   | 26 ++++++++++++++++++++
 test/poodinis/valueinjectiontest.d | 39 ++++++++++++++++++++++++++++++
 3 files changed, 68 insertions(+)

diff --git a/source/poodinis/autowire.d b/source/poodinis/autowire.d
index e498c56..0aa4513 100644
--- a/source/poodinis/autowire.d
+++ b/source/poodinis/autowire.d
@@ -135,6 +135,9 @@ private void autowireMember(string member, size_t memberIndex, Type)(shared(Depe
 		} else static if (is(typeof(attribute) == Value)) {
 			enum key = attribute.key;
 			injectValue!(member, memberIndex, key, false)(container, instance);
+		} else static if (is(typeof(attribute) == MandatoryValue)) {
+			enum key = attribute.key;
+			injectValue!(member, memberIndex, key, true)(container, instance);
 		}
 	}
 }
diff --git a/source/poodinis/valueinjection.d b/source/poodinis/valueinjection.d
index 4910bb8..8d649a7 100644
--- a/source/poodinis/valueinjection.d
+++ b/source/poodinis/valueinjection.d
@@ -60,6 +60,32 @@ struct Value {
 	string key;
 }
 
+/**
+ * UDA used for marking class members which should be value-injected.
+ *
+ * When the injector throws a ValueNotAvailableException, it is re-thrown
+ * instead of being suppressed.
+ *
+ * A key must be supplied, which can be in any format depending on how
+ * a value injector reads it.
+ *
+ * Examples:
+ * ---
+ * class MyClass {
+ *     @MandatoryValue("general.valueWhichShouldBeThere")
+ *     private int number;
+ * }
+ * ---
+ */
+struct MandatoryValue {
+	/**
+	 * The textual key used to find the value by injectors.
+	 *
+	 * The format is injector-specific.
+	 */
+	string key;
+}
+
 /**
  * Interface which should be implemented by value injectors.
  *
diff --git a/test/poodinis/valueinjectiontest.d b/test/poodinis/valueinjectiontest.d
index 01e8039..89ff347 100644
--- a/test/poodinis/valueinjectiontest.d
+++ b/test/poodinis/valueinjectiontest.d
@@ -30,6 +30,11 @@ version(unittest) {
 		int noms = 9;
 	}
 
+	class ConfigWithMandatory {
+		@MandatoryValue("conf.mustbethere")
+		int nums;
+	}
+
 	// Test injection of values
 	unittest {
 		auto container = new shared DependencyContainer();
@@ -91,4 +96,38 @@ version(unittest) {
 		auto instance = container.resolve!ConfigWithDefaults;
 		assert(instance.noms == 9);
 	}
+
+	// Test mandatory injection of values which are available
+	unittest {
+		auto container = new shared DependencyContainer();
+		container.register!ConfigWithMandatory;
+
+		class IntInjector : ValueInjector!int {
+			public override int get(string key) {
+				return 7466;
+			}
+		}
+
+		container.register!(ValueInjector!int, IntInjector);
+
+		auto instance = container.resolve!ConfigWithMandatory;
+		assert(instance.nums == 7466);
+	}
+
+	// Test mandatory injection of values which are not available
+	unittest {
+		auto container = new shared DependencyContainer();
+		container.register!ConfigWithMandatory;
+
+		class IntInjector : ValueInjector!int {
+			public override int get(string key) {
+				throw new ValueNotAvailableException(key);
+			}
+		}
+
+		container.register!(ValueInjector!int, IntInjector);
+
+		assertThrown!ResolveException(container.resolve!ConfigWithMandatory);
+		assertThrown!ValueInjectionException(autowire(container, new ConfigWithMandatory()));
+	}
 }