Extract plan metadata interface

CHANGELOG.md

@@ -9,6 +9,7 @@ and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0
 ### Added
 
 ### Changed
+- Updated `interfaces.NextArgs` with optional `isOptional` param.
 
 ### Fixed
 

src/container/container.ts

@@ -8,6 +8,7 @@
   createMockRequest,
   getBindingDictionary,
   plan,
+  PlanMetadata,
 } from '../planning/planner';
 import { resolve } from '../resolution/resolver';
 import { BindingToSyntax } from '../syntax/binding_to_syntax';
@@ -319,8 +320,13 @@
       const request: interfaces.Request = createMockRequest(
         this,
         serviceIdentifier,
-        key,
-        value,
+        {
+          customTag: {
+            key,
+            value,
+          },
+          isMultiInject: false,
+        },
       );
       bound = bindings.some((b: interfaces.Binding) => b.constraint(request));
     }
@@ -862,6 +868,27 @@
     return getNotAllArgs;
   }
 
+  private _getPlanMetadataFromNextArgs(
+    args: interfaces.NextArgs<unknown>,
+  ): PlanMetadata {
+    const planMetadata: PlanMetadata = {
+      isMultiInject: args.isMultiInject,
+    };
+
+    if (args.key !== undefined) {
+      planMetadata.customTag = {
+        key: args.key,
+        value: args.value,
+      };
+    }
+
+    if (args.isOptional === true) {
+      planMetadata.isOptional = true;
+    }
+
+    return planMetadata;
+  }
+
   // Planner creates a plan and Resolver resolves a plan
   // one of the jobs of the Container is to links the Planner
   // with the Resolver and that is what this function is about
@@ -875,11 +902,9 @@
       let context: interfaces.Context = plan(
         this._metadataReader,
         this,
-        args.isMultiInject,
         args.targetType,
         args.serviceIdentifier,
-        args.key,
-        args.value,
+        this._getPlanMetadataFromNextArgs(args),
         args.avoidConstraints,
       );
 

src/interfaces/interfaces.ts

@@ -143,6 +143,7 @@ namespace interfaces {
     avoidConstraints: boolean;
     contextInterceptor: (contexts: Context) => Context;
     isMultiInject: boolean;
+    isOptional?: boolean;
     targetType: TargetType;
     serviceIdentifier: interfaces.ServiceIdentifier<T>;
     key?: string | number | symbol | undefined;

src/planning/planner.ts

@@ -28,7 +28,7 @@ import {
 } from './reflection_utils';
 import { Request } from './request';
 
-function getBindingDictionary(
+export function getBindingDictionary(
   cntnr: interfaces.Container,
 ): interfaces.Lookup<interfaces.Binding<unknown>> {
   return (
@@ -39,18 +39,13 @@ function getBindingDictionary(
 }
 
 function _createTarget(
-  isMultiInject: boolean,
   targetType: interfaces.TargetType,
   serviceIdentifier: interfaces.ServiceIdentifier,
-  name: string,
-  key?: string | number | symbol,
-  value?: unknown,
+  metadata: PlanMetadata,
 ): interfaces.Target {
   const metadataList: Metadata[] = _getTargetMetadata(
-    isMultiInject,
     serviceIdentifier,
-    key,
-    value,
+    metadata,
   );
 
   const classElementMetadata: ClassElementMetadata =
@@ -60,7 +55,7 @@ function _createTarget(
     throw new Error('Unexpected metadata when creating target');
   }
 
-  const target: Target = new TargetImpl(name, classElementMetadata, targetType);
+  const target: Target = new TargetImpl('', classElementMetadata, targetType);
 
   return target;
 }
@@ -122,21 +117,25 @@ function _getActiveBindings(
 }
 
 function _getTargetMetadata(
-  isMultiInject: boolean,
   serviceIdentifier: interfaces.ServiceIdentifier,
-  key: string | number | symbol | undefined,
-  value: unknown,
+  metadata: PlanMetadata,
 ): Metadata[] {
-  const metadataKey: string = isMultiInject
+  const metadataKey: string = metadata.isMultiInject
     ? METADATA_KEY.MULTI_INJECT_TAG
     : METADATA_KEY.INJECT_TAG;
 
   const metadataList: Metadata[] = [
     new Metadata(metadataKey, serviceIdentifier),
   ];
 
-  if (key !== undefined) {
-    metadataList.push(new Metadata(key, value));
+  if (metadata.customTag !== undefined) {
+    metadataList.push(
+      new Metadata(metadata.customTag.key, metadata.customTag.value),
+    );
+  }
+
+  if (metadata.isOptional === true) {
+    metadataList.push(new Metadata(METADATA_KEY.OPTIONAL_TAG, true));
   }
 
   return metadataList;
@@ -312,24 +311,28 @@ function getBindings<T>(
   return bindings;
 }
 
-function plan(
+export interface PlanMetadata {
+  isMultiInject: boolean;
+  isOptional?: boolean;
+  customTag?: {
+    key: string | number | symbol;
+    value?: unknown;
+  };
+}
+
+export function plan(
   metadataReader: interfaces.MetadataReader,
   container: interfaces.Container,
-  isMultiInject: boolean,
   targetType: interfaces.TargetType,
   serviceIdentifier: interfaces.ServiceIdentifier,
-  key?: string | number | symbol,
-  value?: unknown,
+  metadata: PlanMetadata,
   avoidConstraints: boolean = false,
 ): interfaces.Context {
   const context: Context = new Context(container);
   const target: interfaces.Target = _createTarget(
-    isMultiInject,
     targetType,
     serviceIdentifier,
-    '',
-    key,
-    value,
+    metadata,
   );
 
   try {
@@ -350,17 +353,14 @@ function plan(
   }
 }
 
-function createMockRequest(
+export function createMockRequest(
   container: interfaces.Container,
   serviceIdentifier: interfaces.ServiceIdentifier,
-  key: string | number | symbol,
-  value: unknown,
+  metadata: PlanMetadata,
 ): interfaces.Request {
   const metadataList: Metadata[] = _getTargetMetadata(
-    false,
     serviceIdentifier,
-    key,
-    value,
+    metadata,
   );
 
   const classElementMetadata: ClassElementMetadata =
@@ -382,5 +382,3 @@ function createMockRequest(
   );
   return request;
 }
-
-export { plan, createMockRequest, getBindingDictionary };

src/test/planning/planner.test.ts

@@ -79,9 +79,11 @@ describe('Planner', () => {
     const actualPlan: Plan = plan(
       new MetadataReader(),
       container,
-      false,
       TargetTypeEnum.Variable,
       ninjaId,
+      {
+        isMultiInject: false,
+      },
     ).plan;
     const actualNinjaRequest: interfaces.Request = actualPlan.rootRequest;
     const actualKatanaRequest: interfaces.Request | undefined =
@@ -122,6 +124,28 @@ describe('Planner', () => {
     expect(actualShurikenRequest?.target.serviceIdentifier).eql(shurikenId);
   });
 
+  it('Should be able to create a basic plan with optional metadata', () => {
+    const ninjaId: string = 'Ninja';
+
+    const container: Container = new Container();
+
+    // Actual
+    const actualPlan: Plan = plan(
+      new MetadataReader(),
+      container,
+      TargetTypeEnum.Variable,
+      ninjaId,
+      {
+        isMultiInject: false,
+        isOptional: true,
+      },
+    ).plan;
+    const actualNinjaRequest: interfaces.Request = actualPlan.rootRequest;
+
+    expect(actualNinjaRequest.serviceIdentifier).eql(ninjaId);
+    expect(actualNinjaRequest.bindings).to.have.length(0);
+  });
+
   it('Should throw when circular dependencies found', () => {
     @injectable()
     class D {
@@ -233,9 +257,11 @@ describe('Planner', () => {
     const actualPlan: Plan = plan(
       new MetadataReader(),
       container,
-      false,
       TargetTypeEnum.Variable,
       ninjaId,
+      {
+        isMultiInject: false,
+      },
     ).plan;
 
     expect(actualPlan.rootRequest.serviceIdentifier).eql(ninjaId);
@@ -285,9 +311,11 @@ describe('Planner', () => {
     const actualPlan: Plan = plan(
       new MetadataReader(),
       container,
-      false,
       TargetTypeEnum.Variable,
       ninjaId,
+      {
+        isMultiInject: false,
+      },
     ).plan;
 
     // root request has no target
@@ -399,13 +427,9 @@ describe('Planner', () => {
     container.bind<Shuriken>(shurikenId).to(Shuriken);
 
     const throwFunction: () => void = () => {
-      plan(
-        new MetadataReader(),
-        container,
-        false,
-        TargetTypeEnum.Variable,
-        ninjaId,
-      );
+      plan(new MetadataReader(), container, TargetTypeEnum.Variable, ninjaId, {
+        isMultiInject: false,
+      });
     };
 
     expect(throwFunction).to.throw(`${ERROR_MSGS.NOT_REGISTERED} Katana`);
@@ -444,13 +468,9 @@ describe('Planner', () => {
     container.bind<Shuriken>(shurikenId).to(Shuriken);
 
     const throwFunction: () => void = () => {
-      plan(
-        new MetadataReader(),
-        container,
-        false,
-        TargetTypeEnum.Variable,
-        ninjaId,
-      );
+      plan(new MetadataReader(), container, TargetTypeEnum.Variable, ninjaId, {
+        isMultiInject: false,
+      });
     };
 
     expect(throwFunction).to.throw(`${ERROR_MSGS.AMBIGUOUS_MATCH} Katana`);
@@ -493,9 +513,11 @@ describe('Planner', () => {
     const actualPlan: Plan = plan(
       new MetadataReader(),
       container,
-      false,
       TargetTypeEnum.Variable,
       ninjaId,
+      {
+        isMultiInject: false,
+      },
     ).plan;
 
     // root request has no target
@@ -534,13 +556,9 @@ describe('Planner', () => {
     container.bind('Weapon').to(Katana);
 
     const throwFunction: () => void = () => {
-      plan(
-        new MetadataReader(),
-        container,
-        false,
-        TargetTypeEnum.Variable,
-        'Weapon',
-      );
+      plan(new MetadataReader(), container, TargetTypeEnum.Variable, 'Weapon', {
+        isMultiInject: false,
+      });
     };
 
     expect(throwFunction).not.to.throw();
@@ -561,13 +579,9 @@ describe('Planner', () => {
     container.bind(Ninja).toSelf();
 
     const throwFunction: () => void = () => {
-      plan(
-        new MetadataReader(),
-        container,
-        false,
-        TargetTypeEnum.Variable,
-        Ninja,
-      );
+      plan(new MetadataReader(), container, TargetTypeEnum.Variable, Ninja, {
+        isMultiInject: false,
+      });
     };
 
     expect(throwFunction).to.throw(
@@ -623,9 +637,11 @@ describe('Planner', () => {
       plan(
         new MetadataReader(),
         container,
-        false,
         TargetTypeEnum.Variable,
         'Warrior',
+        {
+          isMultiInject: false,
+        },
       );
     };
 
@@ -659,13 +675,9 @@ describe('Planner', () => {
     container.bind<Katana>('Factory<Katana>').to(Katana);
 
     const throwFunction: () => void = () => {
-      plan(
-        new MetadataReader(),
-        container,
-        false,
-        TargetTypeEnum.Variable,
-        'Ninja',
-      );
+      plan(new MetadataReader(), container, TargetTypeEnum.Variable, 'Ninja', {
+        isMultiInject: false,
+      });
     };
 
     expect(throwFunction).to.throw(