Resuscitate the SymbolWalker API

Jakefile.js

@@ -140,6 +140,7 @@ var harnessSources = harnessCoreSources.concat([
     "transform.ts",
     "customTransforms.ts",
     "programMissingFiles.ts",
+    "symbolWalker.ts",
 ].map(function (f) {
     return path.join(unittestsDirectory, f);
 })).concat([

src/compiler/checker.ts

@@ -1,5 +1,6 @@
 /// <reference path="moduleNameResolver.ts"/>
 /// <reference path="binder.ts"/>
+/// <reference path="symbolWalker.ts" />
 
 /* @internal */
 namespace ts {
@@ -204,6 +205,7 @@ namespace ts {
             getEmitResolver,
             getExportsOfModule: getExportsOfModuleAsArray,
             getExportsAndPropertiesOfModule,
+            getSymbolWalker: createGetSymbolWalker(getRestTypeOfSignature, getReturnTypeOfSignature, getBaseTypes, resolveStructuredTypeMembers, getTypeOfSymbol, getResolvedSymbol, getIndexTypeOfStructuredType, getConstraintFromTypeParameter, getFirstIdentifier),
             getAmbientModules,
             getAllAttributesTypeFromJsxOpeningLikeElement: node => {
                 node = getParseTreeNode(node, isJsxOpeningLikeElement);

src/compiler/symbolWalker.ts

@@ -0,0 +1,191 @@
+/** @internal */
+namespace ts {
+    export function createGetSymbolWalker(
+        getRestTypeOfSignature: (sig: Signature) => Type,
+        getReturnTypeOfSignature: (sig: Signature) => Type,
+        getBaseTypes: (type: Type) => Type[],
+        resolveStructuredTypeMembers: (type: ObjectType) => ResolvedType,
+        getTypeOfSymbol: (sym: Symbol) => Type,
+        getResolvedSymbol: (node: Node) => Symbol,
+        getIndexTypeOfStructuredType: (type: Type, kind: IndexKind) => Type,
+        getConstraintFromTypeParameter: (typeParameter: TypeParameter) => Type,
+        getFirstIdentifier: (node: EntityNameOrEntityNameExpression) => Identifier) {
+
+        return getSymbolWalker;
+
+        function getSymbolWalker(accept: (symbol: Symbol) => boolean = () => true): SymbolWalker {
+            const visitedTypes = createMap<Type>(); // Key is id as string
+            const visitedSymbols = createMap<Symbol>(); // Key is id as string
+
+            return {
+                walkType: type => {
+                    visitedTypes.clear();
+                    visitedSymbols.clear();
+                    visitType(type);
+                    return { visitedTypes: arrayFrom(visitedTypes.values()), visitedSymbols: arrayFrom(visitedSymbols.values()) };
+                },
+                walkSymbol: symbol => {
+                    visitedTypes.clear();
+                    visitedSymbols.clear();
+                    visitSymbol(symbol);
+                    return { visitedTypes: arrayFrom(visitedTypes.values()), visitedSymbols: arrayFrom(visitedSymbols.values()) };
+                },
+            };
+
+            function visitType(type: Type): void {
+                if (!type) {
+                    return;
+                }
+
+                const typeIdString = type.id.toString();
+                if (visitedTypes.has(typeIdString)) {
+                    return;
+                }
+                visitedTypes.set(typeIdString, type);
+
+                // Reuse visitSymbol to visit the type's symbol,
+                //  but be sure to bail on recuring into the type if accept declines the symbol.
+                const shouldBail = visitSymbol(type.symbol);
+                if (shouldBail) return;
+
+                // Visit the type's related types, if any
+                if (type.flags & TypeFlags.Object) {
+                    const objectType = type as ObjectType;
+                    const objectFlags = objectType.objectFlags;
+                    if (objectFlags & ObjectFlags.Reference) {
+                        visitTypeReference(type as TypeReference);
+                    }
+                    if (objectFlags & ObjectFlags.Mapped) {
+                        visitMappedType(type as MappedType);
+                    }
+                    if (objectFlags & (ObjectFlags.Class | ObjectFlags.Interface)) {
+                        visitInterfaceType(type as InterfaceType);
+                    }
+                    if (objectFlags & (ObjectFlags.Tuple | ObjectFlags.Anonymous)) {
+                        visitObjectType(objectType);
+                    }
+                }
+                if (type.flags & TypeFlags.TypeParameter) {
+                    visitTypeParameter(type as TypeParameter);
+                }
+                if (type.flags & TypeFlags.UnionOrIntersection) {
+                    visitUnionOrIntersectionType(type as UnionOrIntersectionType);
+                }
+                if (type.flags & TypeFlags.Index) {
+                    visitIndexType(type as IndexType);
+                }
+                if (type.flags & TypeFlags.IndexedAccess) {
+                    visitIndexedAccessType(type as IndexedAccessType);
+                }
+            }
+
+            function visitTypeList(types: Type[]): void {
+                if (!types) {
+                    return;
+                }
+                for (let i = 0; i < types.length; i++) {
+                    visitType(types[i]);
+                }
+            }
+
+            function visitTypeReference(type: TypeReference): void {
+                visitType(type.target);
+                visitTypeList(type.typeArguments);
+            }
+
+            function visitTypeParameter(type: TypeParameter): void {
+                visitType(getConstraintFromTypeParameter(type));
+            }
+
+            function visitUnionOrIntersectionType(type: UnionOrIntersectionType): void {
+                visitTypeList(type.types);
+            }
+
+            function visitIndexType(type: IndexType): void {
+                visitType(type.type);
+            }
+
+            function visitIndexedAccessType(type: IndexedAccessType): void {
+                visitType(type.objectType);
+                visitType(type.indexType);
+                visitType(type.constraint);
+            }
+
+            function visitMappedType(type: MappedType): void {
+                visitType(type.typeParameter);
+                visitType(type.constraintType);
+                visitType(type.templateType);
+                visitType(type.modifiersType);
+            }
+
+            function visitSignature(signature: Signature): void {
+                if (signature.typePredicate) {
+                    visitType(signature.typePredicate.type);
+                }
+                visitTypeList(signature.typeParameters);
+
+                for (const parameter of signature.parameters){
+                    visitSymbol(parameter);
+                }
+                visitType(getRestTypeOfSignature(signature));
+                visitType(getReturnTypeOfSignature(signature));
+            }
+
+            function visitInterfaceType(interfaceT: InterfaceType): void {
+                visitObjectType(interfaceT);
+                visitTypeList(interfaceT.typeParameters);
+                visitTypeList(getBaseTypes(interfaceT));
+                visitType(interfaceT.thisType);
+            }
+
+            function visitObjectType(type: ObjectType): void {
+                const stringIndexType = getIndexTypeOfStructuredType(type, IndexKind.String);
+                visitType(stringIndexType);
+                const numberIndexType = getIndexTypeOfStructuredType(type, IndexKind.Number);
+                visitType(numberIndexType);
+
+                // The two checks above *should* have already resolved the type (if needed), so this should be cached
+                const resolved = resolveStructuredTypeMembers(type);
+                for (const signature of resolved.callSignatures) {
+                    visitSignature(signature);
+                }
+                for (const signature of resolved.constructSignatures) {
+                    visitSignature(signature);
+                }
+                for (const p of resolved.properties) {
+                    visitSymbol(p);
+                }
+            }
+
+            function visitSymbol(symbol: Symbol): boolean {
+                if (!symbol) {
+                    return;
+                }
+                const symbolIdString = getSymbolId(symbol).toString();
+                if (visitedSymbols.has(symbolIdString)) {
+                    return;
+                }
+                visitedSymbols.set(symbolIdString, symbol);
+                if (!accept(symbol)) {
+                    return true;
+                }
+                const t = getTypeOfSymbol(symbol);
+                visitType(t); // Should handle members on classes and such
+                if (symbol.flags & SymbolFlags.HasExports) {
+                    symbol.exports.forEach(visitSymbol);
+                }
+                forEach(symbol.declarations, d => {
+                    // Type queries are too far resolved when we just visit the symbol's type
+                    //  (their type resolved directly to the member deeply referenced)
+                    // So to get the intervening symbols, we need to check if there's a type
+                    // query node on any of the symbol's declarations and get symbols there
+                    if ((d as any).type && (d as any).type.kind === SyntaxKind.TypeQuery) {
+                        const query = (d as any).type as TypeQueryNode;
+                        const entity = getResolvedSymbol(getFirstIdentifier(query.exprName));
+                        visitSymbol(entity);
+                    }
+                });
+            }
+        }
+    }
+}

src/compiler/tsconfig.json

@@ -14,6 +14,7 @@
         "parser.ts",
         "utilities.ts",
         "binder.ts",
+        "symbolWalker.ts",
         "checker.ts",
         "factory.ts",
         "visitor.ts",

src/compiler/types.ts

@@ -2625,6 +2625,8 @@ namespace ts {
 
         /* @internal */ tryFindAmbientModuleWithoutAugmentations(moduleName: string): Symbol | undefined;
 
+        /* @internal */ getSymbolWalker(accept?: (symbol: Symbol) => boolean): SymbolWalker;
+
         // Should not be called directly.  Should only be accessed through the Program instance.
         /* @internal */ getDiagnostics(sourceFile?: SourceFile, cancellationToken?: CancellationToken): Diagnostic[];
         /* @internal */ getGlobalDiagnostics(): Diagnostic[];
@@ -2669,6 +2671,14 @@ namespace ts {
         InTypeAlias                             = 1 << 23,    // Writing type in type alias declaration
     }
 
+    /* @internal */
+    export interface SymbolWalker {
+        /** Note: Return values are not ordered. */
+        walkType(root: Type): { visitedTypes: ReadonlyArray<Type>, visitedSymbols: ReadonlyArray<Symbol> };
+        /** Note: Return values are not ordered. */
+        walkSymbol(root: Symbol): { visitedTypes: ReadonlyArray<Type>, visitedSymbols: ReadonlyArray<Symbol> };
+    }
+
     export interface SymbolDisplayBuilder {
         buildTypeDisplay(type: Type, writer: SymbolWriter, enclosingDeclaration?: Node, flags?: TypeFormatFlags): void;
         buildSymbolDisplay(symbol: Symbol, writer: SymbolWriter, enclosingDeclaration?: Node, meaning?: SymbolFlags, flags?: SymbolFormatFlags): void;
@@ -3367,6 +3377,7 @@ namespace ts {
 
     // Type parameters (TypeFlags.TypeParameter)
     export interface TypeParameter extends TypeVariable {
+        /** Retrieve using getConstraintFromTypeParameter */
         constraint: Type;        // Constraint
         default?: Type;
         /* @internal */

src/harness/tsconfig.json

@@ -21,6 +21,7 @@
         "../compiler/parser.ts",
         "../compiler/utilities.ts",
         "../compiler/binder.ts",
+        "../compiler/symbolWalker.ts",
         "../compiler/checker.ts",
         "../compiler/factory.ts",
         "../compiler/visitor.ts",
@@ -103,6 +104,7 @@
         "./unittests/services/preProcessFile.ts",
         "./unittests/services/patternMatcher.ts",
         "./unittests/session.ts",
+        "./unittests/symbolWalker.ts",
         "./unittests/versionCache.ts",
         "./unittests/convertToBase64.ts",
         "./unittests/transpile.ts",

src/harness/unittests/symbolWalker.ts

@@ -0,0 +1,51 @@
+/// <reference path="..\harness.ts" />
+
+namespace ts {
+    describe("Symbol Walker", () => {
+        function test(description: string, source: string, verifier: (file: SourceFile, checker: TypeChecker) => void) {
+            it(description, () => {
+                let {result} = Harness.Compiler.compileFiles([{
+                    unitName: "main.ts",
+                    content: source
+                }], [], {}, {}, "/");
+                let file = result.program.getSourceFile("main.ts");
+                let checker = result.program.getTypeChecker();
+                verifier(file, checker);
+
+                result = undefined;
+                file = undefined;
+                checker = undefined;
+            });
+        }
+
+        test("can be created", `
+interface Bar {
+    x: number;
+    y: number;
+    history: Bar[];
+}
+export default function foo(a: number, b: Bar): void {}`, (file, checker) => {
+            let foundCount = 0;
+            let stdLibRefSymbols = 0;
+            const expectedSymbols = ["default", "a", "b", "Bar", "x", "y", "history"];
+            const walker = checker.getSymbolWalker(symbol => {
+                const isStdLibSymbol = forEach(symbol.declarations, d => {
+                    return getSourceFileOfNode(d).hasNoDefaultLib;
+                });
+                if (isStdLibSymbol) {
+                    stdLibRefSymbols++;
+                    return false; // Don't traverse into the stdlib. That's unnecessary for this test.
+                }
+                assert.equal(symbol.name, expectedSymbols[foundCount]);
+                foundCount++;
+                return true;
+            });
+            const symbols = checker.getExportsOfModule(file.symbol);
+            for (const symbol of symbols) {
+                walker.walkSymbol(symbol);
+            }
+            assert.equal(foundCount, expectedSymbols.length);
+            assert.equal(stdLibRefSymbols, 1); // Expect 1 stdlib entry symbol - the implicit Array referenced by Bar.history
+        });
+    });
+}

src/services/tsconfig.json

@@ -14,6 +14,7 @@
         "../compiler/parser.ts",
         "../compiler/utilities.ts",
         "../compiler/binder.ts",
+        "../compiler/symbolWalker.ts",
         "../compiler/checker.ts",
         "../compiler/factory.ts",
         "../compiler/visitor.ts",