valid-expect-in-promise.js
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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.default = void 0;
var _experimentalUtils = require("@typescript-eslint/experimental-utils");
var _utils = require("./utils");
const isPromiseChainCall = node => {
if (node.type === _experimentalUtils.AST_NODE_TYPES.CallExpression && node.callee.type === _experimentalUtils.AST_NODE_TYPES.MemberExpression && (0, _utils.isSupportedAccessor)(node.callee.property)) {
// promise methods should have at least 1 argument
if (node.arguments.length === 0) {
return false;
}
switch ((0, _utils.getAccessorValue)(node.callee.property)) {
case 'then':
return node.arguments.length < 3;
case 'catch':
case 'finally':
return node.arguments.length < 2;
}
}
return false;
};
const findTopMostCallExpression = node => {
let topMostCallExpression = node;
let {
parent
} = node;
while (parent) {
if (parent.type === _experimentalUtils.AST_NODE_TYPES.CallExpression) {
topMostCallExpression = parent;
parent = parent.parent;
continue;
}
if (parent.type !== _experimentalUtils.AST_NODE_TYPES.MemberExpression) {
break;
}
parent = parent.parent;
}
return topMostCallExpression;
};
const isTestCaseCallWithCallbackArg = node => {
if (!(0, _utils.isTestCaseCall)(node)) {
return false;
}
const isJestEach = (0, _utils.getNodeName)(node).endsWith('.each');
if (isJestEach && node.callee.type !== _experimentalUtils.AST_NODE_TYPES.TaggedTemplateExpression) {
// isJestEach but not a TaggedTemplateExpression, so this must be
// the `jest.each([])()` syntax which this rule doesn't support due
// to its complexity (see jest-community/eslint-plugin-jest#710)
// so we return true to trigger bailout
return true;
}
if (isJestEach || node.arguments.length >= 2) {
const [, callback] = node.arguments;
const callbackArgIndex = Number(isJestEach);
return callback && (0, _utils.isFunction)(callback) && callback.params.length === 1 + callbackArgIndex;
}
return false;
};
const isPromiseMethodThatUsesValue = (node, identifier) => {
const {
name
} = identifier;
if (node.argument === null) {
return false;
}
if (node.argument.type === _experimentalUtils.AST_NODE_TYPES.CallExpression && node.argument.arguments.length > 0) {
const nodeName = (0, _utils.getNodeName)(node.argument);
if (['Promise.all', 'Promise.allSettled'].includes(nodeName)) {
const [firstArg] = node.argument.arguments;
if (firstArg.type === _experimentalUtils.AST_NODE_TYPES.ArrayExpression && firstArg.elements.some(nod => (0, _utils.isIdentifier)(nod, name))) {
return true;
}
}
if (['Promise.resolve', 'Promise.reject'].includes(nodeName) && node.argument.arguments.length === 1) {
return (0, _utils.isIdentifier)(node.argument.arguments[0], name);
}
}
return (0, _utils.isIdentifier)(node.argument, name);
};
/**
* Attempts to determine if the runtime value represented by the given `identifier`
* is `await`ed within the given array of elements
*/
const isValueAwaitedInElements = (name, elements) => {
for (const element of elements) {
if (element.type === _experimentalUtils.AST_NODE_TYPES.AwaitExpression && (0, _utils.isIdentifier)(element.argument, name)) {
return true;
}
if (element.type === _experimentalUtils.AST_NODE_TYPES.ArrayExpression && isValueAwaitedInElements(name, element.elements)) {
return true;
}
}
return false;
};
/**
* Attempts to determine if the runtime value represented by the given `identifier`
* is `await`ed as an argument along the given call expression
*/
const isValueAwaitedInArguments = (name, call) => {
let node = call;
while (node) {
if (node.type === _experimentalUtils.AST_NODE_TYPES.CallExpression) {
if (isValueAwaitedInElements(name, node.arguments)) {
return true;
}
node = node.callee;
}
if (node.type !== _experimentalUtils.AST_NODE_TYPES.MemberExpression) {
break;
}
node = node.object;
}
return false;
};
const getLeftMostCallExpression = call => {
let leftMostCallExpression = call;
let node = call;
while (node) {
if (node.type === _experimentalUtils.AST_NODE_TYPES.CallExpression) {
leftMostCallExpression = node;
node = node.callee;
}
if (node.type !== _experimentalUtils.AST_NODE_TYPES.MemberExpression) {
break;
}
node = node.object;
}
return leftMostCallExpression;
};
/**
* Attempts to determine if the runtime value represented by the given `identifier`
* is `await`ed or `return`ed within the given `body` of statements
*/
const isValueAwaitedOrReturned = (identifier, body) => {
const {
name
} = identifier;
for (const node of body) {
// skip all nodes that are before this identifier, because they'd probably
// be affecting a different runtime value (e.g. due to reassignment)
if (node.range[0] <= identifier.range[0]) {
continue;
}
if (node.type === _experimentalUtils.AST_NODE_TYPES.ReturnStatement) {
return isPromiseMethodThatUsesValue(node, identifier);
}
if (node.type === _experimentalUtils.AST_NODE_TYPES.ExpressionStatement) {
// it's possible that we're awaiting the value as an argument
if (node.expression.type === _experimentalUtils.AST_NODE_TYPES.CallExpression) {
if (isValueAwaitedInArguments(name, node.expression)) {
return true;
}
const leftMostCall = getLeftMostCallExpression(node.expression);
if ((0, _utils.isExpectCall)(leftMostCall) && leftMostCall.arguments.length > 0 && (0, _utils.isIdentifier)(leftMostCall.arguments[0], name)) {
const {
modifier
} = (0, _utils.parseExpectCall)(leftMostCall);
if ((modifier === null || modifier === void 0 ? void 0 : modifier.name) === _utils.ModifierName.resolves || (modifier === null || modifier === void 0 ? void 0 : modifier.name) === _utils.ModifierName.rejects) {
return true;
}
}
}
if (node.expression.type === _experimentalUtils.AST_NODE_TYPES.AwaitExpression && isPromiseMethodThatUsesValue(node.expression, identifier)) {
return true;
} // (re)assignment changes the runtime value, so if we've not found an
// await or return already we act as if we've reached the end of the body
if (node.expression.type === _experimentalUtils.AST_NODE_TYPES.AssignmentExpression) {
var _getNodeName;
// unless we're assigning to the same identifier, in which case
// we might be chaining off the existing promise value
if ((0, _utils.isIdentifier)(node.expression.left, name) && (_getNodeName = (0, _utils.getNodeName)(node.expression.right)) !== null && _getNodeName !== void 0 && _getNodeName.startsWith(`${name}.`) && isPromiseChainCall(node.expression.right)) {
continue;
}
break;
}
}
if (node.type === _experimentalUtils.AST_NODE_TYPES.BlockStatement && isValueAwaitedOrReturned(identifier, node.body)) {
return true;
}
}
return false;
};
const findFirstBlockBodyUp = node => {
let parent = node;
while (parent) {
if (parent.type === _experimentalUtils.AST_NODE_TYPES.BlockStatement) {
return parent.body;
}
parent = parent.parent;
}
/* istanbul ignore next */
throw new Error(`Could not find BlockStatement - please file a github issue at https://github.com/jest-community/eslint-plugin-jest`);
};
const isDirectlyWithinTestCaseCall = node => {
let parent = node;
while (parent) {
if ((0, _utils.isFunction)(parent)) {
var _parent;
parent = parent.parent;
return !!(((_parent = parent) === null || _parent === void 0 ? void 0 : _parent.type) === _experimentalUtils.AST_NODE_TYPES.CallExpression && (0, _utils.isTestCaseCall)(parent));
}
parent = parent.parent;
}
return false;
};
const isVariableAwaitedOrReturned = variable => {
const body = findFirstBlockBodyUp(variable); // it's pretty much impossible for us to track destructuring assignments,
// so we return true to bailout gracefully
if (!(0, _utils.isIdentifier)(variable.id)) {
return true;
}
return isValueAwaitedOrReturned(variable.id, body);
};
var _default = (0, _utils.createRule)({
name: __filename,
meta: {
docs: {
category: 'Best Practices',
description: 'Ensure promises that have expectations in their chain are valid',
recommended: 'error'
},
messages: {
expectInFloatingPromise: "This promise should either be returned or awaited to ensure the expects in it's chain are called"
},
type: 'suggestion',
schema: []
},
defaultOptions: [],
create(context) {
let inTestCaseWithDoneCallback = false; // an array of booleans representing each promise chain we enter, with the
// boolean value representing if we think a given chain contains an expect
// in it's body.
//
// since we only care about the inner-most chain, we represent the state in
// reverse with the inner-most being the first item, as that makes it
// slightly less code to assign to by not needing to know the length
const chains = [];
return {
CallExpression(node) {
// there are too many ways that the done argument could be used with
// promises that contain expect that would make the promise safe for us
if (isTestCaseCallWithCallbackArg(node)) {
inTestCaseWithDoneCallback = true;
return;
} // if this call expression is a promise chain, add it to the stack with
// value of "false", as we assume there are no expect calls initially
if (isPromiseChainCall(node)) {
chains.unshift(false);
return;
} // if we're within a promise chain, and this call expression looks like
// an expect call, mark the deepest chain as having an expect call
if (chains.length > 0 && (0, _utils.isExpectCall)(node)) {
chains[0] = true;
}
},
'CallExpression:exit'(node) {
// there are too many ways that the "done" argument could be used to
// make promises containing expects safe in a test for us to be able to
// accurately check, so we just bail out completely if it's present
if (inTestCaseWithDoneCallback) {
if ((0, _utils.isTestCaseCall)(node)) {
inTestCaseWithDoneCallback = false;
}
return;
}
if (!isPromiseChainCall(node)) {
return;
} // since we're exiting this call expression (which is a promise chain)
// we remove it from the stack of chains, since we're unwinding
const hasExpectCall = chains.shift(); // if the promise chain we're exiting doesn't contain an expect,
// then we don't need to check it for anything
if (!hasExpectCall) {
return;
}
const {
parent
} = findTopMostCallExpression(node); // if we don't have a parent (which is technically impossible at runtime)
// or our parent is not directly within the test case, we stop checking
// because we're most likely in the body of a function being defined
// within the test, which we can't track
if (!parent || !isDirectlyWithinTestCaseCall(parent)) {
return;
}
switch (parent.type) {
case _experimentalUtils.AST_NODE_TYPES.VariableDeclarator:
{
if (isVariableAwaitedOrReturned(parent)) {
return;
}
break;
}
case _experimentalUtils.AST_NODE_TYPES.AssignmentExpression:
{
if (parent.left.type === _experimentalUtils.AST_NODE_TYPES.Identifier && isValueAwaitedOrReturned(parent.left, findFirstBlockBodyUp(parent))) {
return;
}
break;
}
case _experimentalUtils.AST_NODE_TYPES.ExpressionStatement:
break;
case _experimentalUtils.AST_NODE_TYPES.ReturnStatement:
case _experimentalUtils.AST_NODE_TYPES.AwaitExpression:
default:
return;
}
context.report({
messageId: 'expectInFloatingPromise',
node: parent
});
}
};
}
});
exports.default = _default;