From f6cf0c6e5ea3594417fd303c64d04a923c03a627 Mon Sep 17 00:00:00 2001
From: Raymond Feng <enjoyjava@gmail.com>
Date: Mon, 11 Mar 2019 09:39:15 -0700
Subject: [PATCH] feat(context): improve typing for binding related methods

---
 packages/context/src/binding-inspector.ts | 12 +++++++-----
 packages/context/src/binding.ts           |  2 +-
 2 files changed, 8 insertions(+), 6 deletions(-)

diff --git a/packages/context/src/binding-inspector.ts b/packages/context/src/binding-inspector.ts
index 56af3dd313a1..4ac8685738da 100644
--- a/packages/context/src/binding-inspector.ts
+++ b/packages/context/src/binding-inspector.ts
@@ -136,7 +136,9 @@ export function removeNameAndKeyTags(binding: Binding<unknown>) {
  *
  * @param cls A class with optional `@bind`
  */
-export function bindingTemplateFor(cls: Constructor<unknown>): BindingTemplate {
+export function bindingTemplateFor<T = unknown>(
+  cls: Constructor<T | Provider<T>>,
+): BindingTemplate<T> {
   const spec = getBindingMetadata(cls);
   const templateFunctions = (spec && spec.templates) || [
     asClassOrProvider(cls),
@@ -198,16 +200,16 @@ export type BindingFromClassOptions = {
  * @param cls A class
  * @param options Options to customize the binding key
  */
-export function createBindingFromClass(
-  cls: Constructor<unknown>,
+export function createBindingFromClass<T = unknown>(
+  cls: Constructor<T | Provider<T>>,
   options: BindingFromClassOptions = {},
-): Binding {
+): Binding<T> {
   const templateFn = bindingTemplateFor(cls);
   let key = options.key;
   if (!key) {
     key = buildBindingKey(cls, options);
   }
-  const binding = Binding.bind(key).apply(templateFn);
+  const binding = Binding.bind<T>(key).apply(templateFn);
   if (options.name) {
     binding.tag({name: options.name});
   }
diff --git a/packages/context/src/binding.ts b/packages/context/src/binding.ts
index ea98e72238d8..cfbbd110d69b 100644
--- a/packages/context/src/binding.ts
+++ b/packages/context/src/binding.ts
@@ -473,7 +473,7 @@ export class Binding<T = BoundValue> {
    * easy to read.
    * @param key Binding key
    */
-  static bind<T = unknown>(key: BindingAddress<T>): Binding {
+  static bind<T = unknown>(key: BindingAddress<T>): Binding<T> {
     return new Binding(key.toString());
   }
 }