fix(core): remove side effects from ɵɵgetInheritedFactory() (#35769)

dgp1130 · atscott · commit c195d22f686d · 2020-03-03T08:50:03.000-08:00
`ɵɵgetInheritedFactory()` is called from generated code for a component which extends another class. This function is detected by Closure to have a side effect and is not able to tree shake the component as a result. Marking it with `noSideEffects()` tells Closure it can remove this function under the relevant tree shaking conditions. PR Close #35769
diff --git a/integration/_payload-limits.json b/integration/_payload-limits.json
@@ -60,7 +60,7 @@
       "uncompressed": {
         "bundle": "TODO(i): temporarily increase the payload size limit from 105779 - this is due to a closure issue related to ESM reexports that still needs to be investigated",
         "bundle": "TODO(i): we should define ngDevMode to false in Closure, but --define only works in the global scope.",
-        "bundle": 175498
+        "bundle": 170618
       }
     }
   }
diff --git a/packages/core/src/render3/di.ts b/packages/core/src/render3/di.ts
@@ -14,6 +14,7 @@ import {getInjectorDef} from '../di/interface/defs';
 import {InjectFlags} from '../di/interface/injector';
 import {Type} from '../interface/type';
 import {assertDefined, assertEqual} from '../util/assert';
+import {noSideEffects} from '../util/closure';
 
 import {assertDirectiveDef} from './assert';
 import {getFactoryDef} from './definition';
@@ -655,15 +656,17 @@ export function ɵɵgetFactoryOf<T>(type: Type<any>): FactoryFn<T>|null {
  * @codeGenApi
  */
 export function ɵɵgetInheritedFactory<T>(type: Type<any>): (type: Type<T>) => T {
-  const proto = Object.getPrototypeOf(type.prototype).constructor as Type<any>;
-  const factory = (proto as any)[NG_FACTORY_DEF] || ɵɵgetFactoryOf<T>(proto);
-  if (factory !== null) {
-    return factory;
-  } else {
-    // There is no factory defined. Either this was improper usage of inheritance
-    // (no Angular decorator on the superclass) or there is no constructor at all
-    // in the inheritance chain. Since the two cases cannot be distinguished, the
-    // latter has to be assumed.
-    return (t) => new t();
-  }
+  return noSideEffects(() => {
+    const proto = Object.getPrototypeOf(type.prototype).constructor as Type<any>;
+    const factory = (proto as any)[NG_FACTORY_DEF] || ɵɵgetFactoryOf<T>(proto);
+    if (factory !== null) {
+      return factory;
+    } else {
+      // There is no factory defined. Either this was improper usage of inheritance
+      // (no Angular decorator on the superclass) or there is no constructor at all
+      // in the inheritance chain. Since the two cases cannot be distinguished, the
+      // latter has to be assumed.
+      return (t) => new t();
+    }
+  });
 }
diff --git a/packages/core/test/bundling/cyclic_import/bundle.golden_symbols.json b/packages/core/test/bundling/cyclic_import/bundle.golden_symbols.json
@@ -167,6 +167,9 @@
   {
     "name": "attachPatchData"
   },
+  {
+    "name": "autoRegisterModuleById"
+  },
   {
     "name": "baseResolveDirective"
   },

Original file line number	Diff line number	Diff line change
`@@ -60,7 +60,7 @@`
`60`	`60`	`"uncompressed": {`
`61`	`61`	`"bundle": "TODO(i): temporarily increase the payload size limit from 105779 - this is due to a closure issue related to ESM reexports that still needs to be investigated",`
`62`	`62`	`"bundle": "TODO(i): we should define ngDevMode to false in Closure, but --define only works in the global scope.",`
`63`		`- "bundle": 175498`
	`63`	`+ "bundle": 170618`
`64`	`64`	`}`
`65`	`65`	`}`
`66`	`66`	`}`
Original file line number	Diff line number	Diff line change
`@@ -167,6 +167,9 @@`
`167`	`167`	`{`
`168`	`168`	`"name": "attachPatchData"`
`169`	`169`	`},`
	`170`	`+ {`
	`171`	`+ "name": "autoRegisterModuleById"`
	`172`	`+ },`
`170`	`173`	`{`
`171`	`174`	`"name": "baseResolveDirective"`
`172`	`175`	`},`