vscode/build/lib/treeshaking.ts
Matt Bierner 2648263d3e
Run our build scripts directly as typescript (#277567)
* Run our build scripts directly as typescript #277567

Follow up on #276864
For #277526

* Remove a few more ts-node references

* Fix linux and script reference

* Remove `_build-script` ref

* Fix script missing closing quote

* use type only import

* Fix export

* Make sure to run copy-policy-dto

* Make sure we run the copy-policy-dto script

* Enable `verbatimModuleSyntax`

* Pipelines fixes

* Try adding explicit ext to path

* Fix bad edit

* Revert extra `--`

---------

Co-authored-by: João Moreno <joaomoreno@users.noreply.github.com>
2025-11-21 14:56:00 +01:00

928 lines
30 KiB
TypeScript

/*---------------------------------------------------------------------------------------------
* Copyright (c) Microsoft Corporation. All rights reserved.
* Licensed under the MIT License. See License.txt in the project root for license information.
*--------------------------------------------------------------------------------------------*/
import fs from 'fs';
import path from 'path';
import * as ts from 'typescript';
import { type IFileMap, TypeScriptLanguageServiceHost } from './typeScriptLanguageServiceHost.ts';
const ShakeLevel = Object.freeze({
Files: 0,
InnerFile: 1,
ClassMembers: 2
});
type ShakeLevel = typeof ShakeLevel[keyof typeof ShakeLevel];
export function toStringShakeLevel(shakeLevel: ShakeLevel): string {
switch (shakeLevel) {
case ShakeLevel.Files:
return 'Files (0)';
case ShakeLevel.InnerFile:
return 'InnerFile (1)';
case ShakeLevel.ClassMembers:
return 'ClassMembers (2)';
}
}
export interface ITreeShakingOptions {
/**
* The full path to the root where sources are.
*/
sourcesRoot: string;
/**
* Module ids.
* e.g. `vs/editor/editor.main` or `index`
*/
entryPoints: string[];
/**
* Inline usages.
*/
inlineEntryPoints: string[];
/**
* Other .d.ts files
*/
typings: string[];
/**
* TypeScript compiler options.
*/
compilerOptions?: any;
/**
* The shake level to perform.
*/
shakeLevel: ShakeLevel;
/**
* regex pattern to ignore certain imports e.g. `.css` imports
*/
importIgnorePattern: RegExp;
}
export interface ITreeShakingResult {
[file: string]: string;
}
function printDiagnostics(options: ITreeShakingOptions, diagnostics: ReadonlyArray<ts.Diagnostic>): void {
for (const diag of diagnostics) {
let result = '';
if (diag.file) {
result += `${path.join(options.sourcesRoot, diag.file.fileName)}`;
}
if (diag.file && diag.start) {
const location = diag.file.getLineAndCharacterOfPosition(diag.start);
result += `:${location.line + 1}:${location.character}`;
}
result += ` - ` + JSON.stringify(diag.messageText);
console.log(result);
}
}
export function shake(options: ITreeShakingOptions): ITreeShakingResult {
const languageService = createTypeScriptLanguageService(ts, options);
const program = languageService.getProgram()!;
const globalDiagnostics = program.getGlobalDiagnostics();
if (globalDiagnostics.length > 0) {
printDiagnostics(options, globalDiagnostics);
throw new Error(`Compilation Errors encountered.`);
}
const syntacticDiagnostics = program.getSyntacticDiagnostics();
if (syntacticDiagnostics.length > 0) {
printDiagnostics(options, syntacticDiagnostics);
throw new Error(`Compilation Errors encountered.`);
}
const semanticDiagnostics = program.getSemanticDiagnostics();
if (semanticDiagnostics.length > 0) {
printDiagnostics(options, semanticDiagnostics);
throw new Error(`Compilation Errors encountered.`);
}
markNodes(ts, languageService, options);
return generateResult(ts, languageService, options.shakeLevel);
}
//#region Discovery, LanguageService & Setup
function createTypeScriptLanguageService(ts: typeof import('typescript'), options: ITreeShakingOptions): ts.LanguageService {
// Discover referenced files
const FILES: IFileMap = new Map();
// Add entrypoints
options.entryPoints.forEach(entryPoint => {
const filePath = path.join(options.sourcesRoot, entryPoint);
FILES.set(path.normalize(filePath), fs.readFileSync(filePath).toString());
});
// Add fake usage files
options.inlineEntryPoints.forEach((inlineEntryPoint, index) => {
FILES.set(path.normalize(path.join(options.sourcesRoot, `inlineEntryPoint.${index}.ts`)), inlineEntryPoint);
});
// Add additional typings
options.typings.forEach((typing) => {
const filePath = path.join(options.sourcesRoot, typing);
FILES.set(path.normalize(filePath), fs.readFileSync(filePath).toString());
});
const basePath = path.join(options.sourcesRoot, '..');
const compilerOptions = ts.convertCompilerOptionsFromJson(options.compilerOptions, basePath).options;
const host = new TypeScriptLanguageServiceHost(ts, FILES, compilerOptions);
return ts.createLanguageService(host);
}
//#endregion
//#region Tree Shaking
const NodeColor = Object.freeze({
White: 0,
Gray: 1,
Black: 2
});
type NodeColor = typeof NodeColor[keyof typeof NodeColor];
type ObjectLiteralElementWithName = ts.ObjectLiteralElement & { name: ts.PropertyName; parent: ts.ObjectLiteralExpression | ts.JsxAttributes };
declare module 'typescript' {
interface Node {
$$$color?: NodeColor;
$$$neededSourceFile?: boolean;
symbol?: ts.Symbol;
}
function getContainingObjectLiteralElement(node: ts.Node): ObjectLiteralElementWithName | undefined;
function getNameFromPropertyName(name: ts.PropertyName): string | undefined;
function getPropertySymbolsFromContextualType(node: ObjectLiteralElementWithName, checker: ts.TypeChecker, contextualType: ts.Type, unionSymbolOk: boolean): ReadonlyArray<ts.Symbol>;
}
function getColor(node: ts.Node): NodeColor {
return node.$$$color || NodeColor.White;
}
function setColor(node: ts.Node, color: NodeColor): void {
node.$$$color = color;
}
function markNeededSourceFile(node: ts.SourceFile): void {
node.$$$neededSourceFile = true;
}
function isNeededSourceFile(node: ts.SourceFile): boolean {
return Boolean(node.$$$neededSourceFile);
}
function nodeOrParentIsBlack(node: ts.Node): boolean {
while (node) {
const color = getColor(node);
if (color === NodeColor.Black) {
return true;
}
node = node.parent;
}
return false;
}
function nodeOrChildIsBlack(node: ts.Node): boolean {
if (getColor(node) === NodeColor.Black) {
return true;
}
for (const child of node.getChildren()) {
if (nodeOrChildIsBlack(child)) {
return true;
}
}
return false;
}
function isSymbolWithDeclarations(symbol: ts.Symbol | undefined | null): symbol is ts.Symbol & { declarations: ts.Declaration[] } {
return !!(symbol && symbol.declarations);
}
function isVariableStatementWithSideEffects(ts: typeof import('typescript'), node: ts.Node): boolean {
if (!ts.isVariableStatement(node)) {
return false;
}
let hasSideEffects = false;
const visitNode = (node: ts.Node) => {
if (hasSideEffects) {
// no need to go on
return;
}
if (ts.isCallExpression(node) || ts.isNewExpression(node)) {
// TODO: assuming `createDecorator` and `refineServiceDecorator` calls are side-effect free
const isSideEffectFree = /(createDecorator|refineServiceDecorator)/.test(node.expression.getText());
if (!isSideEffectFree) {
hasSideEffects = true;
}
}
node.forEachChild(visitNode);
};
node.forEachChild(visitNode);
return hasSideEffects;
}
function isStaticMemberWithSideEffects(ts: typeof import('typescript'), node: ts.ClassElement | ts.TypeElement): boolean {
if (!ts.isPropertyDeclaration(node)) {
return false;
}
if (!node.modifiers) {
return false;
}
if (!node.modifiers.some(mod => mod.kind === ts.SyntaxKind.StaticKeyword)) {
return false;
}
let hasSideEffects = false;
const visitNode = (node: ts.Node) => {
if (hasSideEffects) {
// no need to go on
return;
}
if (ts.isCallExpression(node) || ts.isNewExpression(node)) {
hasSideEffects = true;
}
node.forEachChild(visitNode);
};
node.forEachChild(visitNode);
return hasSideEffects;
}
function markNodes(ts: typeof import('typescript'), languageService: ts.LanguageService, options: ITreeShakingOptions) {
const program = languageService.getProgram();
if (!program) {
throw new Error('Could not get program from language service');
}
if (options.shakeLevel === ShakeLevel.Files) {
// Mark all source files Black
program.getSourceFiles().forEach((sourceFile) => {
setColor(sourceFile, NodeColor.Black);
});
return;
}
const black_queue: ts.Node[] = [];
const gray_queue: ts.Node[] = [];
const export_import_queue: ts.Node[] = [];
const sourceFilesLoaded: { [fileName: string]: boolean } = {};
function enqueueTopLevelModuleStatements(sourceFile: ts.SourceFile): void {
sourceFile.forEachChild((node: ts.Node) => {
if (ts.isImportDeclaration(node)) {
if (!node.importClause && ts.isStringLiteral(node.moduleSpecifier)) {
setColor(node, NodeColor.Black);
enqueueImport(node, node.moduleSpecifier.text);
}
return;
}
if (ts.isExportDeclaration(node)) {
if (!node.exportClause && node.moduleSpecifier && ts.isStringLiteral(node.moduleSpecifier)) {
// export * from "foo";
setColor(node, NodeColor.Black);
enqueueImport(node, node.moduleSpecifier.text);
}
if (node.exportClause && ts.isNamedExports(node.exportClause)) {
for (const exportSpecifier of node.exportClause.elements) {
export_import_queue.push(exportSpecifier);
}
}
return;
}
if (isVariableStatementWithSideEffects(ts, node)) {
enqueue_black(node);
}
if (
ts.isExpressionStatement(node)
|| ts.isIfStatement(node)
|| ts.isIterationStatement(node, true)
|| ts.isExportAssignment(node)
) {
enqueue_black(node);
}
if (ts.isImportEqualsDeclaration(node)) {
if (/export/.test(node.getFullText(sourceFile))) {
// e.g. "export import Severity = BaseSeverity;"
enqueue_black(node);
}
}
});
}
/**
* Return the parent of `node` which is an ImportDeclaration
*/
function findParentImportDeclaration(node: ts.Declaration): ts.ImportDeclaration | null {
let _node: ts.Node = node;
do {
if (ts.isImportDeclaration(_node)) {
return _node;
}
_node = _node.parent;
} while (_node);
return null;
}
function enqueue_gray(node: ts.Node): void {
if (nodeOrParentIsBlack(node) || getColor(node) === NodeColor.Gray) {
return;
}
setColor(node, NodeColor.Gray);
gray_queue.push(node);
}
function enqueue_black(node: ts.Node): void {
const previousColor = getColor(node);
if (previousColor === NodeColor.Black) {
return;
}
if (previousColor === NodeColor.Gray) {
// remove from gray queue
gray_queue.splice(gray_queue.indexOf(node), 1);
setColor(node, NodeColor.White);
// add to black queue
enqueue_black(node);
// move from one queue to the other
// black_queue.push(node);
// setColor(node, NodeColor.Black);
return;
}
if (nodeOrParentIsBlack(node)) {
return;
}
const fileName = node.getSourceFile().fileName;
if (/^defaultLib:/.test(fileName) || /\.d\.ts$/.test(fileName)) {
setColor(node, NodeColor.Black);
return;
}
const sourceFile = node.getSourceFile();
if (!sourceFilesLoaded[sourceFile.fileName]) {
sourceFilesLoaded[sourceFile.fileName] = true;
enqueueTopLevelModuleStatements(sourceFile);
}
if (ts.isSourceFile(node)) {
return;
}
setColor(node, NodeColor.Black);
black_queue.push(node);
if (options.shakeLevel === ShakeLevel.ClassMembers && (ts.isMethodDeclaration(node) || ts.isMethodSignature(node) || ts.isPropertySignature(node) || ts.isPropertyDeclaration(node) || ts.isGetAccessor(node) || ts.isSetAccessor(node))) {
const references = languageService.getReferencesAtPosition(node.getSourceFile().fileName, node.name.pos + node.name.getLeadingTriviaWidth());
if (references) {
for (let i = 0, len = references.length; i < len; i++) {
const reference = references[i];
const referenceSourceFile = program!.getSourceFile(reference.fileName);
if (!referenceSourceFile) {
continue;
}
const referenceNode = getTokenAtPosition(ts, referenceSourceFile, reference.textSpan.start, false, false);
if (
ts.isMethodDeclaration(referenceNode.parent)
|| ts.isPropertyDeclaration(referenceNode.parent)
|| ts.isGetAccessor(referenceNode.parent)
|| ts.isSetAccessor(referenceNode.parent)
) {
enqueue_gray(referenceNode.parent);
}
}
}
}
}
function enqueueFile(filename: string): void {
const sourceFile = program!.getSourceFile(filename);
if (!sourceFile) {
console.warn(`Cannot find source file ${filename}`);
return;
}
// This source file should survive even if it is empty
markNeededSourceFile(sourceFile);
enqueue_black(sourceFile);
}
function enqueueImport(node: ts.Node, importText: string): void {
if (options.importIgnorePattern.test(importText)) {
// this import should be ignored
return;
}
const nodeSourceFile = node.getSourceFile();
let fullPath: string;
if (/(^\.\/)|(^\.\.\/)/.test(importText)) {
if (importText.endsWith('.js')) { // ESM: code imports require to be relative and to have a '.js' file extension
importText = importText.substr(0, importText.length - 3);
}
fullPath = path.join(path.dirname(nodeSourceFile.fileName), importText);
} else {
fullPath = importText;
}
if (fs.existsSync(fullPath + '.ts')) {
fullPath = fullPath + '.ts';
} else {
fullPath = fullPath + '.js';
}
enqueueFile(fullPath);
}
options.entryPoints.forEach(moduleId => enqueueFile(path.join(options.sourcesRoot, moduleId)));
// Add fake usage files
options.inlineEntryPoints.forEach((_, index) => enqueueFile(path.join(options.sourcesRoot, `inlineEntryPoint.${index}.ts`)));
let step = 0;
const checker = program.getTypeChecker();
while (black_queue.length > 0 || gray_queue.length > 0) {
++step;
let node: ts.Node;
if (step % 100 === 0) {
console.log(`Treeshaking - ${Math.floor(100 * step / (step + black_queue.length + gray_queue.length))}% - ${step}/${step + black_queue.length + gray_queue.length} (${black_queue.length}, ${gray_queue.length})`);
}
if (black_queue.length === 0) {
for (let i = 0; i < gray_queue.length; i++) {
const node = gray_queue[i];
const nodeParent = node.parent;
if ((ts.isClassDeclaration(nodeParent) || ts.isInterfaceDeclaration(nodeParent)) && nodeOrChildIsBlack(nodeParent)) {
gray_queue.splice(i, 1);
black_queue.push(node);
setColor(node, NodeColor.Black);
i--;
}
}
}
if (black_queue.length > 0) {
node = black_queue.shift()!;
} else {
// only gray nodes remaining...
break;
}
const nodeSourceFile = node.getSourceFile();
const loop = (node: ts.Node) => {
const symbols = getRealNodeSymbol(ts, checker, node);
for (const { symbol, symbolImportNode } of symbols) {
if (symbolImportNode) {
setColor(symbolImportNode, NodeColor.Black);
const importDeclarationNode = findParentImportDeclaration(symbolImportNode);
if (importDeclarationNode && ts.isStringLiteral(importDeclarationNode.moduleSpecifier)) {
enqueueImport(importDeclarationNode, importDeclarationNode.moduleSpecifier.text);
}
}
if (isSymbolWithDeclarations(symbol) && !nodeIsInItsOwnDeclaration(nodeSourceFile, node, symbol)) {
for (let i = 0, len = symbol.declarations.length; i < len; i++) {
const declaration = symbol.declarations[i];
if (ts.isSourceFile(declaration)) {
// Do not enqueue full source files
// (they can be the declaration of a module import)
continue;
}
if (options.shakeLevel === ShakeLevel.ClassMembers && (ts.isClassDeclaration(declaration) || ts.isInterfaceDeclaration(declaration)) && !isLocalCodeExtendingOrInheritingFromDefaultLibSymbol(ts, program, checker, declaration)) {
enqueue_black(declaration.name!);
for (let j = 0; j < declaration.members.length; j++) {
const member = declaration.members[j];
const memberName = member.name ? member.name.getText() : null;
if (
ts.isConstructorDeclaration(member)
|| ts.isConstructSignatureDeclaration(member)
|| ts.isIndexSignatureDeclaration(member)
|| ts.isCallSignatureDeclaration(member)
|| memberName === '[Symbol.iterator]'
|| memberName === '[Symbol.toStringTag]'
|| memberName === 'toJSON'
|| memberName === 'toString'
|| memberName === 'dispose'// TODO: keeping all `dispose` methods
|| /^_(.*)Brand$/.test(memberName || '') // TODO: keeping all members ending with `Brand`...
) {
enqueue_black(member);
}
if (isStaticMemberWithSideEffects(ts, member)) {
enqueue_black(member);
}
}
// queue the heritage clauses
if (declaration.heritageClauses) {
for (const heritageClause of declaration.heritageClauses) {
enqueue_black(heritageClause);
}
}
} else {
enqueue_black(declaration);
}
}
}
}
node.forEachChild(loop);
};
node.forEachChild(loop);
}
while (export_import_queue.length > 0) {
const node = export_import_queue.shift()!;
if (nodeOrParentIsBlack(node)) {
continue;
}
if (!node.symbol) {
continue;
}
const aliased = checker.getAliasedSymbol(node.symbol);
if (aliased.declarations && aliased.declarations.length > 0) {
if (nodeOrParentIsBlack(aliased.declarations[0]) || nodeOrChildIsBlack(aliased.declarations[0])) {
setColor(node, NodeColor.Black);
}
}
}
}
function nodeIsInItsOwnDeclaration(nodeSourceFile: ts.SourceFile, node: ts.Node, symbol: ts.Symbol & { declarations: ts.Declaration[] }): boolean {
for (let i = 0, len = symbol.declarations.length; i < len; i++) {
const declaration = symbol.declarations[i];
const declarationSourceFile = declaration.getSourceFile();
if (nodeSourceFile === declarationSourceFile) {
if (declaration.pos <= node.pos && node.end <= declaration.end) {
return true;
}
}
}
return false;
}
function generateResult(ts: typeof import('typescript'), languageService: ts.LanguageService, shakeLevel: ShakeLevel): ITreeShakingResult {
const program = languageService.getProgram();
if (!program) {
throw new Error('Could not get program from language service');
}
const result: ITreeShakingResult = {};
const writeFile = (filePath: string, contents: string): void => {
result[filePath] = contents;
};
program.getSourceFiles().forEach((sourceFile) => {
const fileName = sourceFile.fileName;
if (/^defaultLib:/.test(fileName)) {
return;
}
const destination = fileName;
if (/\.d\.ts$/.test(fileName)) {
if (nodeOrChildIsBlack(sourceFile)) {
writeFile(destination, sourceFile.text);
}
return;
}
const text = sourceFile.text;
let result = '';
function keep(node: ts.Node): void {
result += text.substring(node.pos, node.end);
}
function write(data: string): void {
result += data;
}
function writeMarkedNodes(node: ts.Node): void {
if (getColor(node) === NodeColor.Black) {
return keep(node);
}
// Always keep certain top-level statements
if (ts.isSourceFile(node.parent)) {
if (ts.isExpressionStatement(node) && ts.isStringLiteral(node.expression) && node.expression.text === 'use strict') {
return keep(node);
}
if (ts.isVariableStatement(node) && nodeOrChildIsBlack(node)) {
return keep(node);
}
}
// Keep the entire import in import * as X cases
if (ts.isImportDeclaration(node)) {
if (node.importClause && node.importClause.namedBindings) {
if (ts.isNamespaceImport(node.importClause.namedBindings)) {
if (getColor(node.importClause.namedBindings) === NodeColor.Black) {
return keep(node);
}
} else {
const survivingImports: string[] = [];
for (const importNode of node.importClause.namedBindings.elements) {
if (getColor(importNode) === NodeColor.Black) {
survivingImports.push(importNode.getFullText(sourceFile));
}
}
const leadingTriviaWidth = node.getLeadingTriviaWidth();
const leadingTrivia = sourceFile.text.substr(node.pos, leadingTriviaWidth);
if (survivingImports.length > 0) {
if (node.importClause && node.importClause.name && getColor(node.importClause) === NodeColor.Black) {
return write(`${leadingTrivia}import ${node.importClause.name.text}, {${survivingImports.join(',')} } from${node.moduleSpecifier.getFullText(sourceFile)};`);
}
return write(`${leadingTrivia}import {${survivingImports.join(',')} } from${node.moduleSpecifier.getFullText(sourceFile)};`);
} else {
if (node.importClause && node.importClause.name && getColor(node.importClause) === NodeColor.Black) {
return write(`${leadingTrivia}import ${node.importClause.name.text} from${node.moduleSpecifier.getFullText(sourceFile)};`);
}
}
}
} else {
if (node.importClause && getColor(node.importClause) === NodeColor.Black) {
return keep(node);
}
}
}
if (ts.isExportDeclaration(node)) {
if (node.exportClause && node.moduleSpecifier && ts.isNamedExports(node.exportClause)) {
const survivingExports: string[] = [];
for (const exportSpecifier of node.exportClause.elements) {
if (getColor(exportSpecifier) === NodeColor.Black) {
survivingExports.push(exportSpecifier.getFullText(sourceFile));
}
}
const leadingTriviaWidth = node.getLeadingTriviaWidth();
const leadingTrivia = sourceFile.text.substr(node.pos, leadingTriviaWidth);
if (survivingExports.length > 0) {
return write(`${leadingTrivia}export {${survivingExports.join(',')} } from${node.moduleSpecifier.getFullText(sourceFile)};`);
}
}
}
if (shakeLevel === ShakeLevel.ClassMembers && (ts.isClassDeclaration(node) || ts.isInterfaceDeclaration(node)) && nodeOrChildIsBlack(node)) {
let toWrite = node.getFullText();
for (let i = node.members.length - 1; i >= 0; i--) {
const member = node.members[i];
if (getColor(member) === NodeColor.Black || !member.name) {
// keep method
continue;
}
const pos = member.pos - node.pos;
const end = member.end - node.pos;
toWrite = toWrite.substring(0, pos) + toWrite.substring(end);
}
return write(toWrite);
}
if (ts.isFunctionDeclaration(node)) {
// Do not go inside functions if they haven't been marked
return;
}
node.forEachChild(writeMarkedNodes);
}
if (getColor(sourceFile) !== NodeColor.Black) {
if (!nodeOrChildIsBlack(sourceFile)) {
// none of the elements are reachable
if (isNeededSourceFile(sourceFile)) {
// this source file must be written, even if nothing is used from it
// because there is an import somewhere for it.
// However, TS complains with empty files with the error "x" is not a module,
// so we will export a dummy variable
result = 'export const __dummy = 0;';
} else {
// don't write this file at all!
return;
}
} else {
sourceFile.forEachChild(writeMarkedNodes);
result += sourceFile.endOfFileToken.getFullText(sourceFile);
}
} else {
result = text;
}
writeFile(destination, result);
});
return result;
}
//#endregion
//#region Utils
function isLocalCodeExtendingOrInheritingFromDefaultLibSymbol(ts: typeof import('typescript'), program: ts.Program, checker: ts.TypeChecker, declaration: ts.ClassDeclaration | ts.InterfaceDeclaration): boolean {
if (!program.isSourceFileDefaultLibrary(declaration.getSourceFile()) && declaration.heritageClauses) {
for (const heritageClause of declaration.heritageClauses) {
for (const type of heritageClause.types) {
const symbol = findSymbolFromHeritageType(ts, checker, type);
if (symbol) {
const decl = symbol.valueDeclaration || (symbol.declarations && symbol.declarations[0]);
if (decl && program.isSourceFileDefaultLibrary(decl.getSourceFile())) {
return true;
}
}
}
}
}
return false;
}
function findSymbolFromHeritageType(ts: typeof import('typescript'), checker: ts.TypeChecker, type: ts.ExpressionWithTypeArguments | ts.Expression | ts.PrivateIdentifier): ts.Symbol | null {
if (ts.isExpressionWithTypeArguments(type)) {
return findSymbolFromHeritageType(ts, checker, type.expression);
}
if (ts.isIdentifier(type)) {
const tmp = getRealNodeSymbol(ts, checker, type);
return (tmp.length > 0 ? tmp[0].symbol : null);
}
if (ts.isPropertyAccessExpression(type)) {
return findSymbolFromHeritageType(ts, checker, type.name);
}
return null;
}
class SymbolImportTuple {
public readonly symbol: ts.Symbol | null;
public readonly symbolImportNode: ts.Declaration | null;
constructor(
symbol: ts.Symbol | null,
symbolImportNode: ts.Declaration | null
) {
this.symbol = symbol;
this.symbolImportNode = symbolImportNode;
}
}
/**
* Returns the node's symbol and the `import` node (if the symbol resolved from a different module)
*/
function getRealNodeSymbol(ts: typeof import('typescript'), checker: ts.TypeChecker, node: ts.Node): SymbolImportTuple[] {
// Go to the original declaration for cases:
//
// (1) when the aliased symbol was declared in the location(parent).
// (2) when the aliased symbol is originating from an import.
//
function shouldSkipAlias(node: ts.Node, declaration: ts.Node): boolean {
if (!ts.isShorthandPropertyAssignment(node) && node.kind !== ts.SyntaxKind.Identifier) {
return false;
}
if (node.parent === declaration) {
return true;
}
switch (declaration.kind) {
case ts.SyntaxKind.ImportClause:
case ts.SyntaxKind.ImportEqualsDeclaration:
return true;
case ts.SyntaxKind.ImportSpecifier:
return declaration.parent.kind === ts.SyntaxKind.NamedImports;
default:
return false;
}
}
if (!ts.isShorthandPropertyAssignment(node)) {
if (node.getChildCount() !== 0) {
return [];
}
}
const { parent } = node;
let symbol = (
ts.isShorthandPropertyAssignment(node)
? checker.getShorthandAssignmentValueSymbol(node)
: checker.getSymbolAtLocation(node)
);
let importNode: ts.Declaration | null = null;
// If this is an alias, and the request came at the declaration location
// get the aliased symbol instead. This allows for goto def on an import e.g.
// import {A, B} from "mod";
// to jump to the implementation directly.
if (symbol && symbol.flags & ts.SymbolFlags.Alias && symbol.declarations && shouldSkipAlias(node, symbol.declarations[0])) {
const aliased = checker.getAliasedSymbol(symbol);
if (aliased.declarations) {
// We should mark the import as visited
importNode = symbol.declarations[0];
symbol = aliased;
}
}
if (symbol) {
// Because name in short-hand property assignment has two different meanings: property name and property value,
// using go-to-definition at such position should go to the variable declaration of the property value rather than
// go to the declaration of the property name (in this case stay at the same position). However, if go-to-definition
// is performed at the location of property access, we would like to go to definition of the property in the short-hand
// assignment. This case and others are handled by the following code.
if (node.parent.kind === ts.SyntaxKind.ShorthandPropertyAssignment) {
symbol = checker.getShorthandAssignmentValueSymbol(symbol.valueDeclaration);
}
// If the node is the name of a BindingElement within an ObjectBindingPattern instead of just returning the
// declaration the symbol (which is itself), we should try to get to the original type of the ObjectBindingPattern
// and return the property declaration for the referenced property.
// For example:
// import('./foo').then(({ b/*goto*/ar }) => undefined); => should get use to the declaration in file "./foo"
//
// function bar<T>(onfulfilled: (value: T) => void) { //....}
// interface Test {
// pr/*destination*/op1: number
// }
// bar<Test>(({pr/*goto*/op1})=>{});
if (ts.isPropertyName(node) && ts.isBindingElement(parent) && ts.isObjectBindingPattern(parent.parent) &&
(node === (parent.propertyName || parent.name))) {
const name = ts.getNameFromPropertyName(node);
const type = checker.getTypeAtLocation(parent.parent);
if (name && type) {
if (type.isUnion()) {
return generateMultipleSymbols(type, name, importNode);
} else {
const prop = type.getProperty(name);
if (prop) {
symbol = prop;
}
}
}
}
// If the current location we want to find its definition is in an object literal, try to get the contextual type for the
// object literal, lookup the property symbol in the contextual type, and use this for goto-definition.
// For example
// interface Props{
// /*first*/prop1: number
// prop2: boolean
// }
// function Foo(arg: Props) {}
// Foo( { pr/*1*/op1: 10, prop2: false })
const element = ts.getContainingObjectLiteralElement(node);
if (element) {
const contextualType = element && checker.getContextualType(element.parent);
if (contextualType) {
const propertySymbols = ts.getPropertySymbolsFromContextualType(element, checker, contextualType, /*unionSymbolOk*/ false);
if (propertySymbols) {
symbol = propertySymbols[0];
}
}
}
}
if (symbol && symbol.declarations) {
return [new SymbolImportTuple(symbol, importNode)];
}
return [];
function generateMultipleSymbols(type: ts.UnionType, name: string, importNode: ts.Declaration | null): SymbolImportTuple[] {
const result: SymbolImportTuple[] = [];
for (const t of type.types) {
const prop = t.getProperty(name);
if (prop && prop.declarations) {
result.push(new SymbolImportTuple(prop, importNode));
}
}
return result;
}
}
/** Get the token whose text contains the position */
function getTokenAtPosition(ts: typeof import('typescript'), sourceFile: ts.SourceFile, position: number, allowPositionInLeadingTrivia: boolean, includeEndPosition: boolean): ts.Node {
let current: ts.Node = sourceFile;
outer: while (true) {
// find the child that contains 'position'
for (const child of current.getChildren()) {
const start = allowPositionInLeadingTrivia ? child.getFullStart() : child.getStart(sourceFile, /*includeJsDoc*/ true);
if (start > position) {
// If this child begins after position, then all subsequent children will as well.
break;
}
const end = child.getEnd();
if (position < end || (position === end && (child.kind === ts.SyntaxKind.EndOfFileToken || includeEndPosition))) {
current = child;
continue outer;
}
}
return current;
}
}
//#endregion