"use strict"; var __createBinding = (this && this.__createBinding) || (Object.create ? (function(o, m, k, k2) { if (k2 === undefined) k2 = k; var desc = Object.getOwnPropertyDescriptor(m, k); if (!desc || ("get" in desc ? !m.__esModule : desc.writable || desc.configurable)) { desc = { enumerable: true, get: function() { return m[k]; } }; } Object.defineProperty(o, k2, desc); }) : (function(o, m, k, k2) { if (k2 === undefined) k2 = k; o[k2] = m[k]; })); var __setModuleDefault = (this && this.__setModuleDefault) || (Object.create ? (function(o, v) { Object.defineProperty(o, "default", { enumerable: true, value: v }); }) : function(o, v) { o["default"] = v; }); var __importStar = (this && this.__importStar) || function (mod) { if (mod && mod.__esModule) return mod; var result = {}; if (mod != null) for (var k in mod) if (k !== "default" && Object.prototype.hasOwnProperty.call(mod, k)) __createBinding(result, mod, k); __setModuleDefault(result, mod); return result; }; Object.defineProperty(exports, "__esModule", { value: true }); const utils_1 = require("@typescript-eslint/utils"); const tsutils = __importStar(require("ts-api-utils")); const ts = __importStar(require("typescript")); const util_1 = require("../util"); exports.default = (0, util_1.createRule)({ name: 'no-confusing-void-expression', meta: { docs: { description: 'Require expressions of type void to appear in statement position', recommended: 'strict', requiresTypeChecking: true, }, messages: { invalidVoidExpr: 'Placing a void expression inside another expression is forbidden. ' + 'Move it to its own statement instead.', invalidVoidExprWrapVoid: 'Void expressions used inside another expression ' + 'must be moved to its own statement ' + 'or marked explicitly with the `void` operator.', invalidVoidExprArrow: 'Returning a void expression from an arrow function shorthand is forbidden. ' + 'Please add braces to the arrow function.', invalidVoidExprArrowWrapVoid: 'Void expressions returned from an arrow function shorthand ' + 'must be marked explicitly with the `void` operator.', invalidVoidExprReturn: 'Returning a void expression from a function is forbidden. ' + 'Please move it before the `return` statement.', invalidVoidExprReturnLast: 'Returning a void expression from a function is forbidden. ' + 'Please remove the `return` statement.', invalidVoidExprReturnWrapVoid: 'Void expressions returned from a function ' + 'must be marked explicitly with the `void` operator.', voidExprWrapVoid: 'Mark with an explicit `void` operator.', }, schema: [ { type: 'object', properties: { ignoreArrowShorthand: { type: 'boolean' }, ignoreVoidOperator: { type: 'boolean' }, }, additionalProperties: false, }, ], type: 'problem', fixable: 'code', hasSuggestions: true, }, defaultOptions: [{ ignoreArrowShorthand: false, ignoreVoidOperator: false }], create(context, [options]) { return { 'AwaitExpression, CallExpression, TaggedTemplateExpression'(node) { const services = (0, util_1.getParserServices)(context); const type = (0, util_1.getConstrainedTypeAtLocation)(services, node); if (!tsutils.isTypeFlagSet(type, ts.TypeFlags.VoidLike)) { // not a void expression return; } const invalidAncestor = findInvalidAncestor(node); if (invalidAncestor == null) { // void expression is in valid position return; } const wrapVoidFix = (fixer) => { const nodeText = context.sourceCode.getText(node); const newNodeText = `void ${nodeText}`; return fixer.replaceText(node, newNodeText); }; if (invalidAncestor.type === utils_1.AST_NODE_TYPES.ArrowFunctionExpression) { // handle arrow function shorthand if (options.ignoreVoidOperator) { // handle wrapping with `void` return context.report({ node, messageId: 'invalidVoidExprArrowWrapVoid', fix: wrapVoidFix, }); } // handle wrapping with braces const arrowFunction = invalidAncestor; return context.report({ node, messageId: 'invalidVoidExprArrow', fix(fixer) { if (!canFix(arrowFunction)) { return null; } const arrowBody = arrowFunction.body; const arrowBodyText = context.sourceCode.getText(arrowBody); const newArrowBodyText = `{ ${arrowBodyText}; }`; if ((0, util_1.isParenthesized)(arrowBody, context.sourceCode)) { const bodyOpeningParen = context.sourceCode.getTokenBefore(arrowBody, util_1.isOpeningParenToken); const bodyClosingParen = context.sourceCode.getTokenAfter(arrowBody, util_1.isClosingParenToken); return fixer.replaceTextRange([bodyOpeningParen.range[0], bodyClosingParen.range[1]], newArrowBodyText); } return fixer.replaceText(arrowBody, newArrowBodyText); }, }); } if (invalidAncestor.type === utils_1.AST_NODE_TYPES.ReturnStatement) { // handle return statement if (options.ignoreVoidOperator) { // handle wrapping with `void` return context.report({ node, messageId: 'invalidVoidExprReturnWrapVoid', fix: wrapVoidFix, }); } const returnStmt = invalidAncestor; if (isFinalReturn(returnStmt)) { // remove the `return` keyword return context.report({ node, messageId: 'invalidVoidExprReturnLast', fix(fixer) { if (!canFix(returnStmt)) { return null; } const returnValue = returnStmt.argument; const returnValueText = context.sourceCode.getText(returnValue); let newReturnStmtText = `${returnValueText};`; if (isPreventingASI(returnValue)) { // put a semicolon at the beginning of the line newReturnStmtText = `;${newReturnStmtText}`; } return fixer.replaceText(returnStmt, newReturnStmtText); }, }); } // move before the `return` keyword return context.report({ node, messageId: 'invalidVoidExprReturn', fix(fixer) { const returnValue = returnStmt.argument; const returnValueText = context.sourceCode.getText(returnValue); let newReturnStmtText = `${returnValueText}; return;`; if (isPreventingASI(returnValue)) { // put a semicolon at the beginning of the line newReturnStmtText = `;${newReturnStmtText}`; } if (returnStmt.parent.type !== utils_1.AST_NODE_TYPES.BlockStatement) { // e.g. `if (cond) return console.error();` // add braces if not inside a block newReturnStmtText = `{ ${newReturnStmtText} }`; } return fixer.replaceText(returnStmt, newReturnStmtText); }, }); } // handle generic case if (options.ignoreVoidOperator) { // this would be reported by this rule btw. such irony return context.report({ node, messageId: 'invalidVoidExprWrapVoid', suggest: [{ messageId: 'voidExprWrapVoid', fix: wrapVoidFix }], }); } context.report({ node, messageId: 'invalidVoidExpr', }); }, }; /** * Inspects the void expression's ancestors and finds closest invalid one. * By default anything other than an ExpressionStatement is invalid. * Parent expressions which can be used for their short-circuiting behavior * are ignored and their parents are checked instead. * @param node The void expression node to check. * @returns Invalid ancestor node if it was found. `null` otherwise. */ function findInvalidAncestor(node) { const parent = (0, util_1.nullThrows)(node.parent, util_1.NullThrowsReasons.MissingParent); if (parent.type === utils_1.AST_NODE_TYPES.SequenceExpression) { if (node !== parent.expressions[parent.expressions.length - 1]) { return null; } } if (parent.type === utils_1.AST_NODE_TYPES.ExpressionStatement) { // e.g. `{ console.log("foo"); }` // this is always valid return null; } if (parent.type === utils_1.AST_NODE_TYPES.LogicalExpression) { if (parent.right === node) { // e.g. `x && console.log(x)` // this is valid only if the next ancestor is valid return findInvalidAncestor(parent); } } if (parent.type === utils_1.AST_NODE_TYPES.ConditionalExpression) { if (parent.consequent === node || parent.alternate === node) { // e.g. `cond ? console.log(true) : console.log(false)` // this is valid only if the next ancestor is valid return findInvalidAncestor(parent); } } if (parent.type === utils_1.AST_NODE_TYPES.ArrowFunctionExpression) { // e.g. `() => console.log("foo")` // this is valid with an appropriate option if (options.ignoreArrowShorthand) { return null; } } if (parent.type === utils_1.AST_NODE_TYPES.UnaryExpression) { if (parent.operator === 'void') { // e.g. `void console.log("foo")` // this is valid with an appropriate option if (options.ignoreVoidOperator) { return null; } } } if (parent.type === utils_1.AST_NODE_TYPES.ChainExpression) { // e.g. `console?.log('foo')` return findInvalidAncestor(parent); } // any other parent is invalid return parent; } /** Checks whether the return statement is the last statement in a function body. */ function isFinalReturn(node) { // the parent must be a block const block = (0, util_1.nullThrows)(node.parent, util_1.NullThrowsReasons.MissingParent); if (block.type !== utils_1.AST_NODE_TYPES.BlockStatement) { // e.g. `if (cond) return;` (not in a block) return false; } // the block's parent must be a function const blockParent = (0, util_1.nullThrows)(block.parent, util_1.NullThrowsReasons.MissingParent); if (![ utils_1.AST_NODE_TYPES.FunctionDeclaration, utils_1.AST_NODE_TYPES.FunctionExpression, utils_1.AST_NODE_TYPES.ArrowFunctionExpression, ].includes(blockParent.type)) { // e.g. `if (cond) { return; }` // not in a top-level function block return false; } // must be the last child of the block if (block.body.indexOf(node) < block.body.length - 1) { // not the last statement in the block return false; } return true; } /** * Checks whether the given node, if placed on its own line, * would prevent automatic semicolon insertion on the line before. * * This happens if the line begins with `(`, `[` or `` ` `` */ function isPreventingASI(node) { const startToken = (0, util_1.nullThrows)(context.sourceCode.getFirstToken(node), util_1.NullThrowsReasons.MissingToken('first token', node.type)); return ['(', '[', '`'].includes(startToken.value); } function canFix(node) { const services = (0, util_1.getParserServices)(context); const targetNode = node.type === utils_1.AST_NODE_TYPES.ReturnStatement ? node.argument : node.body; const type = (0, util_1.getConstrainedTypeAtLocation)(services, targetNode); return tsutils.isTypeFlagSet(type, ts.TypeFlags.VoidLike); } }, }); //# sourceMappingURL=no-confusing-void-expression.js.map