From 6b8b6d433c371d0482d31b249537278b7cae42f5 Mon Sep 17 00:00:00 2001
From: Konstantin Burov <kburov@snapchat.com>
Date: Tue, 17 Sep 2024 09:34:51 +1000
Subject: [PATCH] PR feedback

---
 src/Injectable.ts                      | 22 ++++++++++++++++++++++
 src/__tests__/PartialContainer.spec.ts | 18 +++++++++++++-----
 2 files changed, 35 insertions(+), 5 deletions(-)

diff --git a/src/Injectable.ts b/src/Injectable.ts
index e7e6109..01e5311 100644
--- a/src/Injectable.ts
+++ b/src/Injectable.ts
@@ -103,6 +103,28 @@ export function Injectable(
 /**
  * Creates an Injectable factory function for an InjectableClass.
  *
+ * @example
+ * ```ts
+ * class InjectableClassService {
+ *     static dependencies = ["service"] as const;
+ *     constructor(public service: string) {}
+ *     public print(): string {
+ *          console.log(this.service);
+ *     }
+ * }
+ *
+ * let container = Container.provides("service", "service value")
+ *      .provides(ClassInjectable("classService", InjectableClassService));
+ *
+ * container.get("classService").print(); // prints "service value"
+ *
+ * // prefer using Container's provideClass method. Above is the equivalent of:
+ * container = Container.provides("service", "service value")
+ *     .providesClass("classService", InjectableClassService);
+ *
+ * container.get("classService").print(); // prints "service value"
+ * ```
+ *
  * @param token Token identifying the Service.
  * @param cls InjectableClass to instantiate.
  */
diff --git a/src/__tests__/PartialContainer.spec.ts b/src/__tests__/PartialContainer.spec.ts
index 47f5459..9780d12 100644
--- a/src/__tests__/PartialContainer.spec.ts
+++ b/src/__tests__/PartialContainer.spec.ts
@@ -132,7 +132,7 @@ describe("PartialContainer", () => {
           () => {
             expect(() => {
               new Container({}).provides(containerWithService).get("TestService");
-            }).toThrow();
+            }).toThrow(/Could not find Service for Token "TestService"/);
 
             new Container({})
               .provides(Injectable("TestService", () => "old service from container"))
@@ -155,12 +155,12 @@ describe("PartialContainer", () => {
     describe("provide service using provideValue", () => {
       const dependenciesContainer = Container.provides(Injectable("TestService", () => "old service"));
 
-      describe("and the new Service does not override", () => {
+      test("and the new Service does not override", () => {
         const partialContainer = new PartialContainer({}).providesValue("NewTestService", "new service");
         expect(dependenciesContainer.provides(partialContainer).get("NewTestService")).toEqual("new service");
       });
 
-      describe("and the new Service does override", () => {
+      test("and the new Service does override", () => {
         const partialContainer = new PartialContainer({}).providesValue("TestService", "new service");
         expect(dependenciesContainer.provides(partialContainer).get("TestService")).toEqual("new service");
       });
@@ -176,10 +176,18 @@ describe("PartialContainer", () => {
 
       describe("and the new Service does not override", () => {
         const partialContainer = new PartialContainer({}).providesClass("NewTestService", NewTestService);
-        expect(dependenciesContainer.provides(partialContainer).get("NewTestService")).toBeInstanceOf(NewTestService);
+        test("fails if parent missing dependency", () => {
+          // @ts-expect-error should be a compile error because nothing provides "TestService"
+          expect(() => Container.provides(partialContainer).get("NewTestService")).toThrow(
+            /Could not find Service for Token "TestService"/
+          );
+        });
+        test("succeeds if parent has dependency", () => {
+          expect(dependenciesContainer.provides(partialContainer).get("NewTestService")).toBeInstanceOf(NewTestService);
+        });
       });
 
-      describe("and the new Service does override", () => {
+      test("and the new Service does override", () => {
         const partialContainer = new PartialContainer({})
           .providesValue("TestService", "old service")
           .providesClass("TestService", NewTestService);