fix(compiler-cli): correctly interpret token arrays in @Injectable deps (#43226)

When specifying the `deps` array in the `@Injectable` decorator to
inject dependencies into the injectable's factory function, it should
be possible to use an array literal to configure how the dependency
should be resolved by the DI system.

For example, the following example is allowed:

```ts
@Injectable({
  providedIn: 'root',
  useFactory: a => new AppService(a),
  deps: [[new Optional(), 'a']],
})
export class AppService {
  constructor(a) {}
}
```

Here, the `'a'` string token should be injected as optional. However,
the AOT compiler incorrectly used the array literal itself as injection
token, resulting in a failure at runtime. Only if the token were to be
provided using `[new Optional(), new Inject('a')]` would it work
correctly.

This commit fixes the issue by using the last non-decorator in the
array literal as the token value, instead of the array literal itself.

Note that this is a loose interpretation of array literals: if a token
is omitted from the array literal then the array literal itself is used
as token, but any decorator such as `new Optional()` would still have
been applied. When there's multiple tokens in the list then only the
last one will be used as actual token, any prior tokens are silently
ignored. This behavior mirrors the JIT interpretation so is kept as is
for now, but may benefit from some stricter checking and better error
reporting in the future.

Fixes #42987

PR Close #43226

Author: wszgrcy

packages/compiler-cli/src/ngtsc/annotations/src/injectable.ts

@@ -280,10 +280,10 @@ function getDep(dep: ts.Expression, reflector: ReflectionHost): R3DependencyMeta
   };
 
   function maybeUpdateDecorator(
-      dec: ts.Identifier, reflector: ReflectionHost, token?: ts.Expression): void {
+      dec: ts.Identifier, reflector: ReflectionHost, token?: ts.Expression): boolean {
     const source = reflector.getImportOfIdentifier(dec);
     if (source === null || source.from !== '@angular/core') {
-      return;
+      return false;
     }
     switch (source.name) {
       case 'Inject':
@@ -300,16 +300,23 @@ function getDep(dep: ts.Expression, reflector: ReflectionHost): R3DependencyMeta
       case 'Self':
         meta.self = true;
         break;
+      default:
+        return false;
     }
+    return true;
   }
 
   if (ts.isArrayLiteralExpression(dep)) {
     dep.elements.forEach(el => {
+      let isDecorator = false;
       if (ts.isIdentifier(el)) {
-        maybeUpdateDecorator(el, reflector);
+        isDecorator = maybeUpdateDecorator(el, reflector);
       } else if (ts.isNewExpression(el) && ts.isIdentifier(el.expression)) {
         const token = el.arguments && el.arguments.length > 0 && el.arguments[0] || undefined;
-        maybeUpdateDecorator(el.expression, reflector, token);
+        isDecorator = maybeUpdateDecorator(el.expression, reflector, token);
+      }
+      if (!isDecorator) {
+        meta.token = new WrappedNodeExpr(el);
       }
     });
   }

packages/compiler-cli/test/compliance/test_cases/r3_view_compiler_di/di/GOLDEN_PARTIAL.js

@@ -162,19 +162,24 @@ export declare class MyService {
 /****************************************************************************************************
  * PARTIAL FILE: usefactory_with_deps.js
  ****************************************************************************************************/
-import { Injectable } from '@angular/core';
+import { Injectable, Optional } from '@angular/core';
 import * as i0 from "@angular/core";
 class SomeDep {
 }
 class MyAlternateService {
+    constructor(dep, optional) { }
 }
 export class MyService {
 }
 MyService.ɵfac = i0.ɵɵngDeclareFactory({ minVersion: "12.0.0", version: "0.0.0-PLACEHOLDER", ngImport: i0, type: MyService, deps: [], target: i0.ɵɵFactoryTarget.Injectable });
-MyService.ɵprov = i0.ɵɵngDeclareInjectable({ minVersion: "12.0.0", version: "0.0.0-PLACEHOLDER", ngImport: i0, type: MyService, providedIn: 'root', useFactory: () => new MyAlternateService(), deps: [{ token: SomeDep }] });
+MyService.ɵprov = i0.ɵɵngDeclareInjectable({ minVersion: "12.0.0", version: "0.0.0-PLACEHOLDER", ngImport: i0, type: MyService, providedIn: 'root', useFactory: (dep, optional) => new MyAlternateService(dep, optional), deps: [{ token: SomeDep }, { token: SomeDep, optional: true }] });
 i0.ɵɵngDeclareClassMetadata({ minVersion: "12.0.0", version: "0.0.0-PLACEHOLDER", ngImport: i0, type: MyService, decorators: [{
             type: Injectable,
-            args: [{ providedIn: 'root', useFactory: () => new MyAlternateService(), deps: [SomeDep] }]
+            args: [{
+                    providedIn: 'root',
+                    useFactory: (dep, optional) => new MyAlternateService(dep, optional),
+                    deps: [SomeDep, [new Optional(), SomeDep]]
+                }]
         }] });
 
 /****************************************************************************************************

packages/compiler-cli/test/compliance/test_cases/r3_view_compiler_di/di/usefactory_with_deps.js

@@ -5,7 +5,7 @@ MyService.ɵprov = /*@__PURE__*/ $r3$.ɵɵdefineInjectable({
     if (t) {
       r = new t();
     } else {
-      r = (() => new MyAlternateService())($r3$.ɵɵinject(SomeDep));
+      r = ((dep, optional) => new MyAlternateService(dep, optional))($r3$.ɵɵinject(SomeDep), $r3$.ɵɵinject(SomeDep, 8));
     }
     return r;
   },

packages/compiler-cli/test/compliance/test_cases/r3_view_compiler_di/di/usefactory_with_deps.ts

@@ -1,8 +1,14 @@
-import {Injectable} from '@angular/core';
+import {Injectable, Optional} from '@angular/core';
 
 class SomeDep {}
-class MyAlternateService {}
+class MyAlternateService {
+  constructor(dep: SomeDep, optional: SomeDep|null) {}
+}
 
-@Injectable({providedIn: 'root', useFactory: () => new MyAlternateService(), deps: [SomeDep]})
+@Injectable({
+  providedIn: 'root',
+  useFactory: (dep: SomeDep, optional: SomeDep|null) => new MyAlternateService(dep, optional),
+  deps: [SomeDep, [new Optional(), SomeDep]]
+})
 export class MyService {
 }

packages/compiler-cli/test/ngtsc/ngtsc_spec.ts

@@ -202,6 +202,40 @@ function allTests(os: string) {
       expect(dtsContents).toContain('static ɵfac: i0.ɵɵFactoryDeclaration<Service, never>;');
     });
 
+    it('should compile Injectables with providedIn and factory with deps with array literal tokens',
+       () => {
+         env.write('test.ts', `
+        import {Injectable, Optional, Self} from '@angular/core';
+
+        @Injectable()
+        export class Dep {}
+
+        @Injectable({
+          providedIn: 'root',
+          useFactory: (dep: Dep) => new Service(dep),
+          deps: [[new Optional(), new Self(), Dep]],
+        })
+        export class Service {
+          constructor(dep: Dep) {}
+        }
+    `);
+
+         env.driveMain();
+
+         const jsContents = env.getContents('test.js');
+         expect(jsContents).toContain('Service.ɵprov =');
+         expect(jsContents)
+             .toContain('factory: function Service_Factory(t) { var r = null; if (t) {');
+         expect(jsContents).toContain('return new (t || Service)(i0.ɵɵinject(Dep));');
+         expect(jsContents)
+             .toContain('r = (function (dep) { return new Service(dep); })(i0.ɵɵinject(Dep, 10));');
+         expect(jsContents).toContain(`return r; }, providedIn: 'root' });`);
+         expect(jsContents).not.toContain('__decorate');
+         const dtsContents = env.getContents('test.d.ts');
+         expect(dtsContents).toContain('static ɵprov: i0.ɵɵInjectableDeclaration<Service>;');
+         expect(dtsContents).toContain('static ɵfac: i0.ɵɵFactoryDeclaration<Service, never>;');
+       });
+
     it('should compile Injectables with providedIn using forwardRef without errors', () => {
       env.write('test.ts', `
         import {Injectable, NgModule, forwardRef} from '@angular/core';