feat(context): allow global interceptors to be sorted by group

loopbackio · May 6, 2019 · cf2ef94 · cf2ef94
1 parent 9dfe950
commit cf2ef94
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diff --git a/docs/site/Interceptors.md b/docs/site/Interceptors.md
@@ -410,6 +410,37 @@ Let's examine the list of interceptors invoked for each method on
 
    Interceptors to apply: [`convertName`, `log`]
 
+Global interceptors are invoked before class/method level ones unless they are
+explicitly overridden by `@intercept`.
+
+Global interceptors can be sorted as follows:
+
+1. Tag global interceptor binding with `ContextTags.GLOBAL_INTERCEPTOR_GROUP`.
+   The tag value will be treated as the `group` name of the interceptor. For
+   example:
+
+   ```ts
+   app
+     .bind('globalInterceptors.authInterceptor')
+     .to(authInterceptor)
+     .apply(asGlobalInterceptor('auth'));
+   ```
+
+   If the group tag does not exist, the value is default to `''`.
+
+2. Control the ordered groups for global interceptors
+
+   ```ts
+   app
+     .bind(ContextBindings.GLOBAL_INTERCEPTOR_ORDERED_GROUPS)
+     .to(['log', 'auth']);
+   ```
+
+If ordered groups is not bound to
+`ContextBindings.GLOBAL_INTERCEPTOR_ORDERED_GROUPS`, global interceptors will be
+sorted by their group names alphabetically. Interceptors with unknown groups are
+invoked before those listed in ordered groups.
+
 ## Create your own interceptors
 
 Interceptors can be made available by LoopBack itself, extension modules, or

diff --git a/packages/context/src/__tests__/acceptance/interceptor.acceptance.ts b/packages/context/src/__tests__/acceptance/interceptor.acceptance.ts
@@ -451,7 +451,7 @@ describe('Interceptor', () => {
       ctx
         .bind('globalLog')
         .to(globalLog)
-        .apply(asGlobalInterceptor);
+        .apply(asGlobalInterceptor());
     }
   });
 

diff --git a/packages/context/src/__tests__/unit/interceptor.unit.ts b/packages/context/src/__tests__/unit/interceptor.unit.ts
@@ -4,7 +4,15 @@
 // License text available at https://opensource.org/licenses/MIT
 
 import {expect} from '@loopback/testlab';
-import {InterceptorOrKey, mergeInterceptors} from '../..';
+import {
+  asGlobalInterceptor,
+  Context,
+  ContextBindings,
+  Interceptor,
+  InterceptorOrKey,
+  InvocationContext,
+  mergeInterceptors,
+} from '../..';
 
 describe('mergeInterceptors', () => {
   it('removes duplicate entries from the spec', () => {
@@ -31,3 +39,118 @@ describe('mergeInterceptors', () => {
     ).to.eql(expectedResult);
   }
 });
+
+describe('globalInterceptors', () => {
+  let ctx: Context;
+
+  const logInterceptor: Interceptor = async (context, next) => {
+    await next();
+  };
+  const authInterceptor: Interceptor = async (context, next) => {
+    await next();
+  };
+
+  beforeEach(givenContext);
+
+  it('sorts by group', () => {
+    ctx
+      .bind(ContextBindings.GLOBAL_INTERCEPTOR_ORDERED_GROUPS)
+      .to(['log', 'auth']);
+
+    ctx
+      .bind('globalInterceptors.authInterceptor')
+      .to(authInterceptor)
+      .apply(asGlobalInterceptor('auth'));
+
+    ctx
+      .bind('globalInterceptors.logInterceptor')
+      .to(logInterceptor)
+      .apply(asGlobalInterceptor('log'));
+
+    const invocationCtx = givenInvocationContext();
+
+    const keys = invocationCtx.getGlobalInterceptorBindingKeys();
+    expect(keys).to.eql([
+      'globalInterceptors.logInterceptor',
+      'globalInterceptors.authInterceptor',
+    ]);
+  });
+
+  it('sorts by group - unknown group comes before known ones', () => {
+    ctx
+      .bind(ContextBindings.GLOBAL_INTERCEPTOR_ORDERED_GROUPS)
+      .to(['log', 'auth']);
+
+    ctx
+      .bind('globalInterceptors.authInterceptor')
+      .to(authInterceptor)
+      .apply(asGlobalInterceptor('auth'));
+
+    ctx
+      .bind('globalInterceptors.logInterceptor')
+      .to(logInterceptor)
+      .apply(asGlobalInterceptor('unknown'));
+
+    const invocationCtx = givenInvocationContext();
+
+    const keys = invocationCtx.getGlobalInterceptorBindingKeys();
+    expect(keys).to.eql([
+      'globalInterceptors.logInterceptor',
+      'globalInterceptors.authInterceptor',
+    ]);
+  });
+
+  it('sorts by group alphabetically without ordered group', () => {
+    ctx
+      .bind('globalInterceptors.authInterceptor')
+      .to(authInterceptor)
+      .apply(asGlobalInterceptor('auth'));
+
+    ctx
+      .bind('globalInterceptors.logInterceptor')
+      .to(logInterceptor)
+      .apply(asGlobalInterceptor('log'));
+
+    const invocationCtx = givenInvocationContext();
+
+    const keys = invocationCtx.getGlobalInterceptorBindingKeys();
+    expect(keys).to.eql([
+      'globalInterceptors.authInterceptor',
+      'globalInterceptors.logInterceptor',
+    ]);
+  });
+
+  it('sorts by binding order without group tags', () => {
+    ctx
+      .bind('globalInterceptors.authInterceptor')
+      .to(authInterceptor)
+      .apply(asGlobalInterceptor());
+
+    ctx
+      .bind('globalInterceptors.logInterceptor')
+      .to(logInterceptor)
+      .apply(asGlobalInterceptor());
+
+    const invocationCtx = givenInvocationContext();
+
+    const keys = invocationCtx.getGlobalInterceptorBindingKeys();
+    expect(keys).to.eql([
+      'globalInterceptors.authInterceptor',
+      'globalInterceptors.logInterceptor',
+    ]);
+  });
+
+  class MyController {
+    greet(name: string) {
+      return `Hello, ${name}`;
+    }
+  }
+
+  function givenContext() {
+    ctx = new Context();
+  }
+
+  function givenInvocationContext() {
+    return new InvocationContext(ctx, new MyController(), 'greet', ['John']);
+  }
+});