fix(ivy): ngcc - identify all ESM5 decorated classes (#27848)

In ESM5 decorated classes can be indicated by calls to `__decorate()`.
Previously the `ReflectionHost.findDecoratedClasses()` call would identify
helper calls of the form:

```
SomeClass = tslib_1.__decorate(...);
```

But it was missing calls of the form:

```
SomeClass = SomeClass_1 = tslib_1.__decorate(...);
```

This form is common in `@NgModule()` decorations, where the class
being decorated is referenced inside the decorator or another
member.

This commit now ensures that a chain of assignments, of any length,
is now identified as a class decoration if it results in a call to
`__decorate()`.

Fixes #27841

PR Close #27848

integration/_payload-limits.json

@@ -12,7 +12,7 @@
     "master": {
       "uncompressed": {
         "runtime": 1440,
-        "main": 507677,
+        "main": 584077,
         "polyfills": 38390
       }
     }

integration/ngcc/yarn.lock

@@ -3,7 +3,7 @@
 
 
 "@angular/animations@file:../../dist/packages-dist/animations":
-  version "7.1.0"
+  version "7.2.0-rc.0"
   dependencies:
     tslib "^1.9.0"
 
@@ -17,12 +17,12 @@
     parse5 "^5.0.0"
 
 "@angular/common@file:../../dist/packages-dist/common":
-  version "7.1.0"
+  version "0.0.0"
   dependencies:
     tslib "^1.9.0"
 
 "@angular/compiler-cli@file:../../dist/packages-dist/compiler-cli":
-  version "7.1.0"
+  version "0.0.0"
   dependencies:
     canonical-path "1.0.0"
     chokidar "^1.4.2"
@@ -37,22 +37,22 @@
     yargs "9.0.1"
 
 "@angular/compiler@file:../../dist/packages-dist/compiler":
-  version "7.1.0"
+  version "7.2.0-rc.0"
   dependencies:
     tslib "^1.9.0"
 
 "@angular/core@file:../../dist/packages-dist/core":
-  version "7.1.0"
+  version "0.0.0"
   dependencies:
     tslib "^1.9.0"
 
 "@angular/forms@file:../../dist/packages-dist/forms":
-  version "7.1.0"
+  version "0.0.0"
   dependencies:
     tslib "^1.9.0"
 
 "@angular/http@file:../../dist/packages-dist/http":
-  version "7.1.0"
+  version "7.2.0-rc.0"
   dependencies:
     tslib "^1.9.0"
 
@@ -66,17 +66,17 @@
     parse5 "^5.0.0"
 
 "@angular/platform-browser-dynamic@file:../../dist/packages-dist/platform-browser-dynamic":
-  version "7.1.0"
+  version "7.2.0-rc.0"
   dependencies:
     tslib "^1.9.0"
 
 "@angular/platform-browser@file:../../dist/packages-dist/platform-browser":
-  version "7.1.0"
+  version "0.0.0"
   dependencies:
     tslib "^1.9.0"
 
 "@angular/router@file:../../dist/packages-dist/router":
-  version "7.1.0"
+  version "0.0.0"
   dependencies:
     tslib "^1.9.0"
 
@@ -3278,7 +3278,7 @@ tweetnacl@^0.14.3, tweetnacl@~0.14.0:
   integrity sha1-WuaBd/GS1EViadEIr6k/+HQ/T2Q=
 
 "typescript@file:../../node_modules/typescript":
-  version "3.1.1"
+  version "3.2.2"
 
 ua-parser-js@0.7.17:
   version "0.7.17"

packages/compiler-cli/src/ngcc/src/host/esm2015_host.ts

@@ -661,8 +661,10 @@ export class Esm2015ReflectionHost extends TypeScriptReflectionHost implements N
    */
   protected getHelperCall(statement: ts.Statement, helperName: string): ts.CallExpression|null {
     if (ts.isExpressionStatement(statement)) {
-      const expression =
-          isAssignmentStatement(statement) ? statement.expression.right : statement.expression;
+      let expression = statement.expression;
+      while (isAssignment(expression)) {
+        expression = expression.right;
+      }
       if (ts.isCallExpression(expression) && getCalleeName(expression) === helperName) {
         return expression;
       }

packages/compiler-cli/src/ngcc/test/host/esm5_host_import_helper_spec.ts

@@ -304,6 +304,27 @@ describe('Esm5ReflectionHost [import helper style]', () => {
         });
       });
 
+      describe('findDecoratedClasses', () => {
+        it('should return an array of all decorated classes in the given source file', () => {
+          const program = makeTestProgram(...fileSystem.files);
+          const host = new Esm5ReflectionHost(false, program.getTypeChecker());
+
+          const ngModuleFile = program.getSourceFile('/ngmodule.js') !;
+          const ngModuleClasses = host.findDecoratedClasses(ngModuleFile);
+          expect(ngModuleClasses.length).toEqual(1);
+          const ngModuleClass = ngModuleClasses.find(c => c.name === 'HttpClientXsrfModule') !;
+          expect(ngModuleClass.decorators.map(decorator => decorator.name)).toEqual(['NgModule']);
+
+          const someDirectiveFile = program.getSourceFile('/some_directive.js') !;
+          const someDirectiveClasses = host.findDecoratedClasses(someDirectiveFile);
+          expect(someDirectiveClasses.length).toEqual(1);
+          const someDirectiveClass = someDirectiveClasses.find(c => c.name === 'SomeDirective') !;
+          expect(someDirectiveClass.decorators.map(decorator => decorator.name)).toEqual([
+            'Directive'
+          ]);
+        });
+      });
+
       describe('getDeclarationOfIdentifier', () => {
         it('should return the declaration of a locally defined identifier', () => {
           const program = makeTestProgram(fileSystem.files[0]);