fix: Add support for directives with a different kind of meta

lib/mock_directive.spec.ts

@@ -1,4 +1,5 @@
 import { Component, Directive, Input } from '@angular/core';
+import { FormControlDirective } from '@angular/forms';
 import { async, ComponentFixture, getTestBed, TestBed } from '@angular/core/testing';
 import { By } from '@angular/platform-browser';
 import {
@@ -64,4 +65,14 @@ describe('MockComponent', () => {
     expect(MockDirective(ExampleDirective)).toEqual(MockDirective(ExampleDirective));
     expect(MockDirective(ExampleDirective)).not.toEqual(ExampleDirective);
   });
+
+  it('can mock formControlDirective from angular', () => {
+    // Some angular directives set up their metadata in a different way than @Directive does
+    // I found that FormControlDirective is one of those weird directives.
+    // Since I don't know how they did it, I don't know how to test it except to write this
+    // test around a known-odd directive.
+    expect(() => {
+      MockDirective(FormControlDirective);
+    }).not.toThrow();
+  });
 });

lib/mock_directive.ts

@@ -8,15 +8,25 @@ export function MockDirective<TDirective>(directive: Type<TDirective>): Type<TDi
     return cacheHit as Type<TDirective>;
   }
 
-  const annotations = (directive as any).__annotations__[0] || {};
+  let annotation: any = {};
+  const annotations: any[] = (directive as any).__annotations__;
+  if (annotations) {
+    annotation = annotations[0];
+  } else {
+    if (!directive.hasOwnProperty('decorators')) {
+      throw new Error(`Cannot find the annotations/decorators for directive ${directive.name}`);
+    }
+    return (directive as any).decorators[0].args[0];
+  }
+
   const propertyMetadata = (directive as any).__prop__metadata__ || {};
 
   const options: Directive = {
-    exportAs: annotations.exportAs,
+    exportAs: annotation.exportAs,
     inputs: Object.keys(propertyMetadata)
                   .filter((meta) => isInput(propertyMetadata[meta]))
                   .map((meta) => [meta, propertyMetadata[meta][0].bindingPropertyName || meta].join(':')),
-    selector: annotations.selector
+    selector: annotation.selector
   };
 
   const mockedDirective =  Directive(options)(class DirectiveMock {} as Type<TDirective>);

package.json

@@ -44,6 +44,7 @@
     "@angular/common": "5.x",
     "@angular/compiler": "5.x",
     "@angular/core": "5.x",
+    "@angular/forms": "5.x",
     "@angular/platform-browser": "5.x",
     "@angular/platform-browser-dynamic": "5.x",
     "@types/core-js": "^0.9.43",