feat(compiler): Support default parameters in static reflector (angular#10370)

Closes: angular#10369

Author: chuckjaz

modules/@angular/compiler-cli/src/static_reflector.ts

@@ -308,12 +308,17 @@ export class StaticReflector implements ReflectorReader {
             }
             calling.set(functionSymbol, true);
             try {
-              let value = targetFunction['value'];
+              const value = targetFunction['value'];
               if (value && (depth != 0 || value.__symbolic != 'error')) {
                 // Determine the arguments
-                let args = (expression['arguments'] || []).map((arg: any) => simplify(arg));
-                let parameters: string[] = targetFunction['parameters'];
-                let functionScope = BindingScope.build();
+                const args: any[] =
+                    (expression['arguments'] || []).map((arg: any) => simplify(arg));
+                const parameters: string[] = targetFunction['parameters'];
+                const defaults: any[] = targetFunction.defaults;
+                if (defaults && defaults.length > args.length) {
+                  args.push(...defaults.slice(args.length).map((value: any) => simplify(value)));
+                }
+                const functionScope = BindingScope.build();
                 for (let i = 0; i < parameters.length; i++) {
                   functionScope.define(parameters[i], args[i]);
                 }

modules/@angular/compiler-cli/test/static_reflector_spec.ts

@@ -421,6 +421,14 @@ describe('StaticReflector', () => {
          [{provider: 'a', useValue: '1'}], [{provider: 'a', useValue: '2'}]
        ]);
      });
+
+  it('should be able to get the metadata for a class calling a method with default parameters',
+     () => {
+       const annotations = reflector.annotations(
+           host.getStaticSymbol('/tmp/src/static-method-call.ts', 'MyDefaultsComponent'));
+       expect(annotations.length).toBe(1);
+       expect(annotations[0].providers).toEqual([['a', true, false]]);
+     });
 });
 
 class MockReflectorHost implements StaticReflectorHost {
@@ -973,6 +981,9 @@ class MockReflectorHost implements StaticReflectorHost {
           static condMethod(cond: boolean) {
             return [{ provider: 'a', useValue: cond ? '1' : '2'}];
           }
+          static defaultsMethod(a, b = true, c = false) {
+            return [a, b, c];
+          }
         }
       `,
       '/tmp/src/static-method-call.ts': `
@@ -988,6 +999,11 @@ class MockReflectorHost implements StaticReflectorHost {
           providers: [MyModule.condMethod(true), MyModule.condMethod(false)]
         })
         export class MyCondComponent { }
+
+        @Component({
+          providers: [MyModule.defaultsMethod('a')]
+        })
+        export class MyDefaultsComponent { }
       `,
       '/tmp/src/static-field.ts': `
         import {Injectable} from 'angular2/core';

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

@@ -1,7 +1,7 @@
 import * as ts from 'typescript';
 
 import {Evaluator, errorSymbol, isPrimitive} from './evaluator';
-import {ClassMetadata, ConstructorMetadata, MemberMetadata, MetadataError, MetadataMap, MetadataObject, MetadataSymbolicExpression, MetadataSymbolicReferenceExpression, MetadataSymbolicSelectExpression, MetadataValue, MethodMetadata, ModuleMetadata, VERSION, isMetadataError, isMetadataSymbolicReferenceExpression, isMetadataSymbolicSelectExpression} from './schema';
+import {ClassMetadata, ConstructorMetadata, FunctionMetadata, MemberMetadata, MetadataError, MetadataMap, MetadataObject, MetadataSymbolicExpression, MetadataSymbolicReferenceExpression, MetadataSymbolicSelectExpression, MetadataValue, MethodMetadata, ModuleMetadata, VERSION, isMetadataError, isMetadataSymbolicReferenceExpression, isMetadataSymbolicSelectExpression} from './schema';
 import {Symbols} from './symbols';
 
 
@@ -19,7 +19,7 @@ export class MetadataCollector {
   public getMetadata(sourceFile: ts.SourceFile): ModuleMetadata {
     const locals = new Symbols(sourceFile);
     const evaluator = new Evaluator(locals);
-    let metadata: {[name: string]: MetadataValue | ClassMetadata}|undefined;
+    let metadata: {[name: string]: MetadataValue | ClassMetadata | FunctionMetadata}|undefined;
 
     function objFromDecorator(decoratorNode: ts.Decorator): MetadataSymbolicExpression {
       return <MetadataSymbolicExpression>evaluator.evaluateNode(decoratorNode.expression);
@@ -32,7 +32,7 @@ export class MetadataCollector {
 
     function maybeGetSimpleFunction(
         functionDeclaration: ts.FunctionDeclaration |
-        ts.MethodDeclaration): {func: MetadataValue, name: string}|undefined {
+        ts.MethodDeclaration): {func: FunctionMetadata, name: string}|undefined {
       if (functionDeclaration.name.kind == ts.SyntaxKind.Identifier) {
         const nameNode = <ts.Identifier>functionDeclaration.name;
         const functionName = nameNode.text;
@@ -42,13 +42,17 @@ export class MetadataCollector {
           if (statement.kind === ts.SyntaxKind.ReturnStatement) {
             const returnStatement = <ts.ReturnStatement>statement;
             if (returnStatement.expression) {
-              return {
-                name: functionName, func: {
-                  __symbolic: 'function',
-                  parameters: namesOf(functionDeclaration.parameters),
-                  value: evaluator.evaluateNode(returnStatement.expression)
-                }
+              const func: FunctionMetadata = {
+                __symbolic: 'function',
+                parameters: namesOf(functionDeclaration.parameters),
+                value: evaluator.evaluateNode(returnStatement.expression)
+              };
+              if (functionDeclaration.parameters.some(p => p.initializer != null)) {
+                const defaults: MetadataValue[] = [];
+                func.defaults = functionDeclaration.parameters.map(
+                    p => p.initializer && evaluator.evaluateNode(p.initializer));
               }
+              return { func, name: functionName }
             }
           }
         }
@@ -90,8 +94,8 @@ export class MetadataCollector {
       }
 
       // static member
-      let statics: MetadataObject = null;
-      function recordStaticMember(name: string, value: MetadataValue) {
+      let statics: {[name: string]: MetadataValue | FunctionMetadata} = null;
+      function recordStaticMember(name: string, value: MetadataValue | FunctionMetadata) {
         if (!statics) statics = {};
         statics[name] = value;
       }

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

@@ -12,7 +12,7 @@ export const VERSION = 1;
 export interface ModuleMetadata {
   __symbolic: 'module';
   version: number;
-  metadata: {[name: string]: (ClassMetadata | MetadataValue)};
+  metadata: {[name: string]: (ClassMetadata | FunctionMetadata | MetadataValue)};
 }
 export function isModuleMetadata(value: any): value is ModuleMetadata {
   return value && value.__symbolic === 'module';
@@ -22,7 +22,7 @@ export interface ClassMetadata {
   __symbolic: 'class';
   decorators?: (MetadataSymbolicExpression|MetadataError)[];
   members?: MetadataMap;
-  statics?: MetadataObject;
+  statics?: {[name: string]: MetadataValue | FunctionMetadata};
 }
 export function isClassMetadata(value: any): value is ClassMetadata {
   return value && value.__symbolic === 'class';
@@ -65,7 +65,8 @@ export function isConstructorMetadata(value: any): value is ConstructorMetadata
 export interface FunctionMetadata {
   __symbolic: 'function';
   parameters: string[];
-  result: MetadataValue;
+  defaults?: MetadataValue[];
+  value: MetadataValue;
 }
 export function isFunctionMetadata(value: any): value is FunctionMetadata {
   return value && value.__symbolic === 'function';

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

@@ -28,6 +28,7 @@ describe('Collector', () => {
       'static-method.ts',
       'static-method-call.ts',
       'static-method-with-if.ts',
+      'static-method-with-default.ts',
     ]);
     service = ts.createLanguageService(host, documentRegistry);
     program = service.getProgram();
@@ -445,6 +446,35 @@ describe('Collector', () => {
       }
     });
   });
+
+  it('should be able to collect a method with a default parameter', () => {
+    let source = program.getSourceFile('/static-method-with-default.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: ['comp', 'foo', 'bar'],
+        defaults: [undefined, true, false],
+        value: [
+          {__symbolic: 'reference', name: 'MyModule'}, {
+            __symbolic: 'if',
+            condition: {__symbolic: 'reference', name: 'foo'},
+            thenExpression: {provider: 'a', useValue: {__symbolic: 'reference', name: 'comp'}},
+            elseExpression: {provider: 'b', useValue: {__symbolic: 'reference', name: 'comp'}}
+          },
+          {
+            __symbolic: 'if',
+            condition: {__symbolic: 'reference', name: 'bar'},
+            thenExpression: {provider: 'c', useValue: {__symbolic: 'reference', name: 'comp'}},
+            elseExpression: {provider: 'd', useValue: {__symbolic: 'reference', name: 'comp'}}
+          }
+        ]
+      }
+    });
+  });
 });
 
 // TODO: Do not use \` in a template literal as it confuses clang-format
@@ -700,6 +730,20 @@ const FILES: Directory = {
       }
     }
   `,
+  'static-method-with-default.ts': `
+    import {Injectable} from 'angular2/core';
+
+    @Injectable()
+    export class MyModule {
+      static with(comp: any, foo: boolean = true, bar: boolean = false): any[] {
+        return [
+          MyModule,
+          foo ? { provider: 'a', useValue: comp } : {provider: 'b', useValue: comp},
+          bar ? { provider: 'c', useValue: comp } : {provider: 'd', useValue: comp}
+        ];
+      }
+    }
+  `,
   'static-method-call.ts': `
     import {Component} from 'angular2/core';
     import {MyModule} from './static-method.ts';