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;