From 0d2e0ee11b64654a8a2b8af88c16b9dcdb244743 Mon Sep 17 00:00:00 2001
From: Paul <paul@technove.co>
Date: Mon, 15 Nov 2021 22:35:22 -0600
Subject: [PATCH] Fix defaultValue

---
 package.json                  |  2 +-
 src/decorators/inject.spec.ts | 15 ++++++++++++++
 src/decorators/inject.ts      | 38 +++++++++++++++++------------------
 3 files changed, 35 insertions(+), 20 deletions(-)

diff --git a/package.json b/package.json
index 62aa653..9027efb 100644
--- a/package.json
+++ b/package.json
@@ -1,7 +1,7 @@
 {
     "name": "@technove/inject",
     "description": "Dependency injection for TypeScript",
-    "version": "0.1.6",
+    "version": "0.1.7",
     "author": "PaulBGD",
     "license": "MIT",
     "scripts": {
diff --git a/src/decorators/inject.spec.ts b/src/decorators/inject.spec.ts
index db819c5..efd2a3c 100644
--- a/src/decorators/inject.spec.ts
+++ b/src/decorators/inject.spec.ts
@@ -4,6 +4,7 @@ import { Inject } from "./inject";
 import { getInjectedData } from "../injector";
 import { expect } from "chai";
 import { it } from "mocha";
+import { Container } from "../container";
 
 describe("@Inject", () => {
     it("adds injected data to the class", () => {
@@ -31,4 +32,18 @@ describe("@Inject", () => {
             }
         }).to.throw("Cannot inject self in constructor");
     });
+
+    it("supports reading the default value", () => {
+        class A {
+            @Inject(
+                (c, field) =>
+                    field.fieldType === "property" && field.defaultValue
+            )
+            val = 5;
+        }
+
+        const container = new Container();
+        const a = container.get(A);
+        expect(a.val).to.be.equal(5);
+    });
 });
diff --git a/src/decorators/inject.ts b/src/decorators/inject.ts
index 695cb5e..4cc8bcb 100644
--- a/src/decorators/inject.ts
+++ b/src/decorators/inject.ts
@@ -9,6 +9,8 @@ export interface InjectProps {
     provider?: FieldProvider<any>;
 }
 
+const NO_VALUE = Symbol("no-value");
+
 export const Inject: (
     props?: InjectProps | FieldProvider<any>
 ) => PropertyDecorator & ParameterDecorator =
@@ -58,9 +60,7 @@ export const Inject: (
         );
 
         if (parameterIndex === undefined) {
-            const defaultValue = (target as any)[propertyName];
-
-            let val: any = undefined;
+            let val: any = NO_VALUE;
             const provider: Provider = (
                 container: Container,
                 target: Object
@@ -68,12 +68,27 @@ export const Inject: (
                 const field: FieldProperty<unknown> = {
                     fieldType: "property",
                     name: propertyName as string,
-                    defaultValue,
+                    defaultValue: (target as any)[propertyName],
                     target,
                     type: propertyType,
                     getValue: () => val,
                 };
 
+                Object.defineProperty(target, propertyName, {
+                    get() {
+                        if (val === NO_VALUE) {
+                            throw new Error(
+                                `Property ${propertyName} has not been injected`
+                            );
+                        }
+                        return val;
+                    },
+
+                    set(newVal: never) {
+                        val = newVal;
+                    },
+                });
+
                 const retrieved = retrievalProvider(container, field);
                 if (retrieved instanceof Promise) {
                     return retrieved.then((newVal) => (val = newVal));
@@ -82,21 +97,6 @@ export const Inject: (
                 }
             };
             data.properties.push(provider);
-
-            Object.defineProperty(target, propertyName, {
-                get() {
-                    if (val === undefined) {
-                        throw new Error(
-                            `Property ${propertyName} has not been injected`
-                        );
-                    }
-                    return val;
-                },
-
-                set(newVal: never) {
-                    val = newVal;
-                },
-            });
         } else {
             if (propertyType === target) {
                 throw new Error("Cannot inject self in constructor");