fix(8223): Preserve Provider expressions

Preserves constructor calls in addition to function calls.
Introduced a special case for forwardRef() similar to CONST_EXPR.

tools/metadata/src/evaluator.ts

@@ -180,6 +180,7 @@ export class Evaluator {
               }
             }
           }
+
           // We can fold a call to CONST_EXPR
           if (isCallOf(callExpression, "CONST_EXPR") && callExpression.arguments.length === 1)
             return this.isFoldableWorker(callExpression.arguments[0], folding);
@@ -286,18 +287,35 @@ export class Evaluator {
         if (isCallOf(callExpression, "CONST_EXPR") && callExpression.arguments.length === 1) {
           return args[0];
         }
+        if (isCallOf(callExpression, 'forwardRef') && callExpression.arguments.length === 1) {
+          const firstArgument = callExpression.arguments[0];
+          if (firstArgument.kind == ts.SyntaxKind.ArrowFunction) {
+            const arrowFunction = <ts.ArrowFunction>firstArgument;
+            return this.evaluateNode(arrowFunction.body);
+          }
+        }
         const expression = this.evaluateNode(callExpression.expression);
         if (isDefined(expression) && args.every(isDefined)) {
-          const result: MetadataSymbolicCallExpression = {
-            __symbolic: "call",
-            expression: this.evaluateNode(callExpression.expression)
-          };
+          const result:
+              MetadataSymbolicCallExpression = {__symbolic: "call", expression: expression};
           if (args && args.length) {
             result.arguments = args;
           }
           return result;
         }
         break;
+      case ts.SyntaxKind.NewExpression:
+        const newExpression = <ts.NewExpression>node;
+        const newArgs = newExpression.arguments.map(arg => this.evaluateNode(arg));
+        const newTarget = this.evaluateNode(newExpression.expression);
+        if (isDefined(newTarget) && newArgs.every(isDefined)) {
+          const result: MetadataSymbolicCallExpression = {__symbolic: "new", expression: newTarget};
+          if (newArgs.length) {
+            result.arguments = newArgs;
+          }
+          return result;
+        }
+        break;
       case ts.SyntaxKind.PropertyAccessExpression: {
         const propertyAccessExpression = <ts.PropertyAccessExpression>node;
         const expression = this.evaluateNode(propertyAccessExpression.expression);

tools/metadata/src/schema.ts

@@ -57,7 +57,7 @@ export interface MetadataObject { [name: string]: MetadataValue; }
 export interface MetadataArray { [name: number]: MetadataValue; }
 
 export interface MetadataSymbolicExpression {
-  __symbolic: "binary" | "call" | "index" | "pre" | "reference" | "select"
+  __symbolic: "binary" | "call" | "index" | "new" | "pre" | "reference" | "select"
 }
 export function isMetadataSymbolicExpression(value: any): value is MetadataSymbolicExpression {
   if (value) {
@@ -65,6 +65,7 @@ export function isMetadataSymbolicExpression(value: any): value is MetadataSymbo
       case "binary":
       case "call":
       case "index":
+      case "new":
       case "pre":
       case "reference":
       case "select":
@@ -97,13 +98,13 @@ export function isMetadataSymbolicIndexExpression(
 }
 
 export interface MetadataSymbolicCallExpression extends MetadataSymbolicExpression {
-  __symbolic: "call";
+  __symbolic: "call" | "new";
   expression: MetadataValue;
   arguments?: MetadataValue[];
 }
 export function isMetadataSymbolicCallExpression(
     value: any): value is MetadataSymbolicCallExpression {
-  return value && value.__symbolic === "call";
+  return value && (value.__symbolic === "call" || value.__symbolic === "new");
 }
 
 export interface MetadataSymbolicPrefixExpression extends MetadataSymbolicExpression {

tools/metadata/test/evaluator.spec.ts

@@ -13,7 +13,9 @@ describe('Evaluator', () => {
   let evaluator: Evaluator;
 
   beforeEach(() => {
-    host = new Host(FILES, ['expressions.ts']);
+    host = new Host(
+        FILES,
+        ['expressions.ts', 'const_expr.ts', 'forwardRef.ts', 'classes.ts', 'newExpression.ts']);
     service = ts.createLanguageService(host);
     program = service.getProgram();
     typeChecker = program.getTypeChecker();
@@ -25,6 +27,7 @@ describe('Evaluator', () => {
     expectNoDiagnostics(service.getCompilerOptionsDiagnostics());
     for (const sourceFile of program.getSourceFiles()) {
       expectNoDiagnostics(service.getSyntacticDiagnostics(sourceFile.fileName));
+      expectNoDiagnostics(service.getSemanticDiagnostics(sourceFile.fileName));
     }
   });
 
@@ -101,6 +104,34 @@ describe('Evaluator', () => {
     expect(evaluator.evaluateNode(findVar(expressions, 'recursiveB').initializer))
         .toEqual({__symbolic: "reference", name: "recursiveA", module: undefined});
   });
+
+  it('should correctly handle special cases for CONST_EXPR', () => {
+    var const_expr = program.getSourceFile('const_expr.ts');
+    expect(evaluator.evaluateNode(findVar(const_expr, 'bTrue').initializer)).toEqual(true);
+    expect(evaluator.evaluateNode(findVar(const_expr, 'bFalse').initializer)).toEqual(false);
+  });
+
+  it('should resolve a forwardRef', () => {
+    var forwardRef = program.getSourceFile('forwardRef.ts');
+    expect(evaluator.evaluateNode(findVar(forwardRef, 'bTrue').initializer)).toEqual(true);
+    expect(evaluator.evaluateNode(findVar(forwardRef, 'bFalse').initializer)).toEqual(false);
+  });
+
+  it('should return new expressions', () => {
+    var newExpression = program.getSourceFile('newExpression.ts');
+    expect(evaluator.evaluateNode(findVar(newExpression, 'someValue').initializer))
+        .toEqual({
+          __symbolic: "new",
+          expression: {__symbolic: "reference", name: "Value", module: "classes.ts"},
+          arguments: ["name", 12]
+        });
+    expect(evaluator.evaluateNode(findVar(newExpression, 'complex').initializer))
+        .toEqual({
+          __symbolic: "new",
+          expression: {__symbolic: "reference", name: "Value", module: "classes.ts"},
+          arguments: ["name", 12]
+        });
+  });
 });
 
 const FILES: Directory = {
@@ -109,6 +140,11 @@ const FILES: Directory = {
       return function(fn: Function) { }
     }
     `,
+  'classes.ts': `
+    export class Value {
+      constructor(public name: string, public value: any) {}
+    }
+  `,
   'consts.ts': `
     export var someName = 'some-name';
     export var someBool = true;
@@ -159,5 +195,22 @@ const FILES: Directory = {
     import {someName, someBool} from './consts';
 
     @Pipe({name: someName, pure: someBool})
-    export class B {}`
+    export class B {}`,
+  'const_expr.ts': `
+    function CONST_EXPR(value: any) { return value; }
+    export var bTrue = CONST_EXPR(true);
+    export var bFalse = CONST_EXPR(false);
+  `,
+  'forwardRef.ts': `
+    function forwardRef(value: any) { return value; }
+    export var bTrue = forwardRef(() => true);
+    export var bFalse = forwardRef(() => false);
+  `,
+  'newExpression.ts': `
+    import {Value} from './classes';
+    function CONST_EXPR(value: any) { return value; }
+    function forwardRef(value: any) { return value; }
+    export const someValue = new Value("name", 12);
+    export const complex = CONST_EXPR(new Value("name", forwardRef(() => 12)));
+  `
 };