feat(compiler): Added support for conditional expressions. (#10366)

Expression evaluated by the static reflector can now supports
conditional expressions.

Closes: #10365

tools/@angular/tsc-wrapped/src/evaluator.ts

@@ -511,6 +511,15 @@ export class Evaluator {
           };
         }
         break;
+      case ts.SyntaxKind.ConditionalExpression:
+        const conditionalExpression = <ts.ConditionalExpression>node;
+        const condition = this.evaluateNode(conditionalExpression.condition);
+        const thenExpression = this.evaluateNode(conditionalExpression.whenTrue);
+        const elseExpression = this.evaluateNode(conditionalExpression.whenFalse);
+        if (isPrimitive(condition)) {
+          return condition ? thenExpression : elseExpression;
+        }
+        return {__symbolic: 'if', condition, thenExpression, elseExpression};
       case ts.SyntaxKind.FunctionExpression:
       case ts.SyntaxKind.ArrowFunction:
         return errorSymbol('Function call not supported', node);

tools/@angular/tsc-wrapped/src/schema.ts

@@ -79,7 +79,7 @@ export interface MetadataObject { [name: string]: MetadataValue; }
 export interface MetadataArray { [name: number]: MetadataValue; }
 
 export interface MetadataSymbolicExpression {
-  __symbolic: 'binary'|'call'|'index'|'new'|'pre'|'reference'|'select'|'spread'
+  __symbolic: 'binary'|'call'|'index'|'new'|'pre'|'reference'|'select'|'spread'|'if'
 }
 export function isMetadataSymbolicExpression(value: any): value is MetadataSymbolicExpression {
   if (value) {
@@ -92,6 +92,7 @@ export function isMetadataSymbolicExpression(value: any): value is MetadataSymbo
       case 'reference':
       case 'select':
       case 'spread':
+      case 'if':
         return true;
     }
   }
@@ -140,6 +141,16 @@ export function isMetadataSymbolicPrefixExpression(value: any):
   return value && value.__symbolic === 'pre';
 }
 
+export interface MetadataSymbolicIfExpression extends MetadataSymbolicExpression {
+  __symbolic: 'if';
+  condition: MetadataValue;
+  thenExpression: MetadataValue;
+  elseExpression: MetadataValue;
+}
+export function isMetadataSymbolicIfExpression(value: any): value is MetadataSymbolicIfExpression {
+  return value && value.__symbolic === 'if';
+}
+
 export interface MetadataGlobalReferenceExpression extends MetadataSymbolicExpression {
   __symbolic: 'reference';
   name: string;

tools/@angular/tsc-wrapped/test/collector.spec.ts

@@ -14,10 +14,20 @@ describe('Collector', () => {
 
   beforeEach(() => {
     host = new Host(FILES, [
-      '/app/app.component.ts', '/app/cases-data.ts', '/app/error-cases.ts', '/promise.ts',
-      '/unsupported-1.ts', '/unsupported-2.ts', 'import-star.ts', 'exported-functions.ts',
-      'exported-enum.ts', 'exported-consts.ts', 'static-method.ts', 'static-method-call.ts',
-      'static-field-reference.ts'
+      '/app/app.component.ts',
+      '/app/cases-data.ts',
+      '/app/error-cases.ts',
+      '/promise.ts',
+      '/unsupported-1.ts',
+      '/unsupported-2.ts',
+      'import-star.ts',
+      'exported-functions.ts',
+      'exported-enum.ts',
+      'exported-consts.ts',
+      'static-field-reference.ts',
+      'static-method.ts',
+      'static-method-call.ts',
+      'static-method-with-if.ts',
     ]);
     service = ts.createLanguageService(host, documentRegistry);
     program = service.getProgram();
@@ -410,6 +420,31 @@ describe('Collector', () => {
       }]
     }]);
   });
+
+  it('should be able to collect a method with a conditional expression', () => {
+    let source = program.getSourceFile('/static-method-with-if.ts');
+    let metadata = collector.getMetadata(source);
+    expect(metadata).toBeDefined();
+    let classData = <ClassMetadata>metadata.metadata['MyModule'];
+    expect(classData).toBeDefined();
+    expect(classData.statics).toEqual({
+      with: {
+        __symbolic: 'function',
+        parameters: ['cond'],
+        value: [
+          {__symbolic: 'reference', name: 'MyModule'}, {
+            provider: 'a',
+            useValue: {
+              __symbolic: 'if',
+              condition: {__symbolic: 'reference', name: 'cond'},
+              thenExpression: '1',
+              elseExpression: '2'
+            }
+          }
+        ]
+      }
+    });
+  });
 });
 
 // TODO: Do not use \` in a template literal as it confuses clang-format
@@ -691,6 +726,19 @@ const FILES: Directory = {
     })
     export class Foo { }
   `,
+  'static-method-with-if.ts': `
+    import {Injectable} from 'angular2/core';
+
+    @Injectable()
+    export class MyModule {
+      static with(cond: boolean): any[] {
+        return [
+          MyModule,
+          { provider: 'a', useValue: cond ? '1' : '2' }
+        ];
+      }
+    }
+  `,
   'node_modules': {
     'angular2': {
       'core.d.ts': `