feat(context): tidy up binding information for inspection

packages/context/src/binding-filter.ts

@@ -4,7 +4,7 @@
 // License text available at https://opensource.org/licenses/MIT
 
 import {Binding, BindingTag} from './binding';
-import {BindingAddress} from './binding-key';
+import {BindingAddress, BindingKey} from './binding-key';
 import {MapObject} from './value-promise';
 
 /**
@@ -52,12 +52,14 @@ export type BindingSelector<ValueType = unknown> =
 
 /**
  * Type guard for binding address
- * @param bindingSelector
+ * @param bindingSelector - Binding key or filter function
  */
 export function isBindingAddress(
   bindingSelector: BindingSelector,
 ): bindingSelector is BindingAddress {
-  return typeof bindingSelector !== 'function';
+  return (
+    typeof bindingSelector === 'string' || bindingSelector instanceof BindingKey
+  );
 }
 
 /**

packages/context/src/binding.ts

@@ -210,6 +210,7 @@ export class Binding<T = BoundValue> extends EventEmitter {
 
   private _valueConstructor?: Constructor<T>;
   private _providerConstructor?: Constructor<Provider<T>>;
+  private _alias?: BindingAddress<T>;
 
   /**
    * For bindings bound via `toClass()`, this property contains the constructor
@@ -595,6 +596,7 @@ export class Binding<T = BoundValue> extends EventEmitter {
       debug('Bind %s to alias %s', this.key, keyWithPath);
     }
     this._type = BindingType.ALIAS;
+    this._alias = keyWithPath;
     this._setValueGetter((ctx, options) => {
       return ctx.getValueOrPromise(keyWithPath, options);
     });
@@ -649,6 +651,9 @@ export class Binding<T = BoundValue> extends EventEmitter {
     if (this._providerConstructor != null) {
       json.providerConstructor = this._providerConstructor.name;
     }
+    if (this._alias != null) {
+      json.alias = this._alias.toString();
+    }
     return json;
   }
 

packages/context/src/resolution-session.ts

@@ -155,9 +155,7 @@ export class ResolutionSession {
    * Describe the injection for debugging purpose
    * @param injection - Injection object
    */
-  static describeInjection(injection?: Readonly<Injection>) {
-    /* istanbul ignore if */
-    if (injection == null) return {};
+  static describeInjection(injection: Readonly<Injection>) {
     const name = getTargetName(
       injection.target,
       injection.member,
@@ -166,8 +164,7 @@ export class ResolutionSession {
     return {
       targetName: name,
       bindingSelector: injection.bindingSelector,
-      // Cast to Object so that we don't have to expose InjectionMetadata
-      metadata: injection.metadata as object,
+      metadata: injection.metadata,
     };
   }
 
@@ -300,14 +297,14 @@ export class ResolutionSession {
    */
   getInjectionPath() {
     return this.injectionStack
-      .map(i => ResolutionSession.describeInjection(i)!.targetName)
+      .map(i => ResolutionSession.describeInjection(i).targetName)
       .join(' --> ');
   }
 
   private static describe(e: ResolutionElement) {
     switch (e.type) {
       case 'injection':
-        return '@' + ResolutionSession.describeInjection(e.value)!.targetName;
+        return '@' + ResolutionSession.describeInjection(e.value).targetName;
       case 'binding':
         return e.value.key;
     }