| "use strict"; |
| var __importStar = (this && this.__importStar) || function (mod) { |
| if (mod && mod.__esModule) return mod; |
| var result = {}; |
| if (mod != null) for (var k in mod) if (Object.hasOwnProperty.call(mod, k)) result[k] = mod[k]; |
| result["default"] = mod; |
| return result; |
| }; |
| Object.defineProperty(exports, "__esModule", { value: true }); |
| const tsutils = __importStar(require("tsutils")); |
| const ts = __importStar(require("typescript")); |
| const util = __importStar(require("../util")); |
| exports.default = util.createRule({ |
| name: 'no-floating-promises', |
| meta: { |
| docs: { |
| description: 'Requires Promise-like values to be handled appropriately.', |
| category: 'Best Practices', |
| recommended: false, |
| }, |
| messages: { |
| floating: 'Promises must be handled appropriately', |
| }, |
| schema: [], |
| type: 'problem', |
| }, |
| defaultOptions: [], |
| create(context) { |
| const parserServices = util.getParserServices(context); |
| const checker = parserServices.program.getTypeChecker(); |
| return { |
| ExpressionStatement(node) { |
| const { expression } = parserServices.esTreeNodeToTSNodeMap.get(node); |
| if (isUnhandledPromise(checker, expression)) { |
| context.report({ |
| messageId: 'floating', |
| node, |
| }); |
| } |
| }, |
| }; |
| }, |
| }); |
| function isUnhandledPromise(checker, node) { |
| // First, check expressions whose resulting types may not be promise-like |
| if (ts.isBinaryExpression(node) && |
| node.operatorToken.kind === ts.SyntaxKind.CommaToken) { |
| // Any child in a comma expression could return a potentially unhandled |
| // promise, so we check them all regardless of whether the final returned |
| // value is promise-like. |
| return (isUnhandledPromise(checker, node.left) || |
| isUnhandledPromise(checker, node.right)); |
| } |
| else if (ts.isVoidExpression(node)) { |
| // Similarly, a `void` expression always returns undefined, so we need to |
| // see what's inside it without checking the type of the overall expression. |
| return isUnhandledPromise(checker, node.expression); |
| } |
| // Check the type. At this point it can't be unhandled if it isn't a promise |
| if (!isPromiseLike(checker, node)) { |
| return false; |
| } |
| if (ts.isCallExpression(node)) { |
| // If the outer expression is a call, it must be either a `.then()` or |
| // `.catch()` that handles the promise. |
| return (!isPromiseCatchCallWithHandler(node) && |
| !isPromiseThenCallWithRejectionHandler(node)); |
| } |
| else if (ts.isConditionalExpression(node)) { |
| // We must be getting the promise-like value from one of the branches of the |
| // ternary. Check them directly. |
| return (isUnhandledPromise(checker, node.whenFalse) || |
| isUnhandledPromise(checker, node.whenTrue)); |
| } |
| else if (ts.isPropertyAccessExpression(node) || |
| ts.isIdentifier(node) || |
| ts.isNewExpression(node)) { |
| // If it is just a property access chain or a `new` call (e.g. `foo.bar` or |
| // `new Promise()`), the promise is not handled because it doesn't have the |
| // necessary then/catch call at the end of the chain. |
| return true; |
| } |
| // We conservatively return false for all other types of expressions because |
| // we don't want to accidentally fail if the promise is handled internally but |
| // we just can't tell. |
| return false; |
| } |
| // Modified from tsutils.isThenable() to only consider thenables which can be |
| // rejected/caught via a second parameter. Original source (MIT licensed): |
| // |
| // https://github.com/ajafff/tsutils/blob/49d0d31050b44b81e918eae4fbaf1dfe7b7286af/util/type.ts#L95-L125 |
| function isPromiseLike(checker, node) { |
| const type = checker.getTypeAtLocation(node); |
| for (const ty of tsutils.unionTypeParts(checker.getApparentType(type))) { |
| const then = ty.getProperty('then'); |
| if (then === undefined) { |
| continue; |
| } |
| const thenType = checker.getTypeOfSymbolAtLocation(then, node); |
| if (hasMatchingSignature(thenType, signature => signature.parameters.length >= 2 && |
| isFunctionParam(checker, signature.parameters[0], node) && |
| isFunctionParam(checker, signature.parameters[1], node))) { |
| return true; |
| } |
| } |
| return false; |
| } |
| function hasMatchingSignature(type, matcher) { |
| for (const t of tsutils.unionTypeParts(type)) { |
| if (t.getCallSignatures().some(matcher)) { |
| return true; |
| } |
| } |
| return false; |
| } |
| function isFunctionParam(checker, param, node) { |
| const type = checker.getApparentType(checker.getTypeOfSymbolAtLocation(param, node)); |
| for (const t of tsutils.unionTypeParts(type)) { |
| if (t.getCallSignatures().length !== 0) { |
| return true; |
| } |
| } |
| return false; |
| } |
| function isPromiseCatchCallWithHandler(expression) { |
| return (tsutils.isPropertyAccessExpression(expression.expression) && |
| expression.expression.name.text === 'catch' && |
| expression.arguments.length >= 1); |
| } |
| function isPromiseThenCallWithRejectionHandler(expression) { |
| return (tsutils.isPropertyAccessExpression(expression.expression) && |
| expression.expression.name.text === 'then' && |
| expression.arguments.length >= 2); |
| } |
| //# sourceMappingURL=no-floating-promises.js.map |