function _optionalChain(ops) { let lastAccessLHS = undefined; let value = ops[0]; let i = 1; while (i < ops.length) { const op = ops[i]; const fn = ops[i + 1]; i += 2; if ((op === 'optionalAccess' || op === 'optionalCall') && value == null) { return undefined; } if (op === 'access' || op === 'optionalAccess') { lastAccessLHS = value; value = fn(value); } else if (op === 'call' || op === 'optionalCall') { value = fn((...args) => value.call(lastAccessLHS, ...args)); lastAccessLHS = undefined; } } return value; } import {TokenType as tt} from "../parser/tokenizer/types"; import Transformer from "./Transformer"; const JEST_GLOBAL_NAME = "jest"; const HOISTED_METHODS = ["mock", "unmock", "enableAutomock", "disableAutomock"]; /** * Implementation of babel-plugin-jest-hoist, which hoists up some jest method * calls above the imports to allow them to override other imports. * * To preserve line numbers, rather than directly moving the jest.mock code, we * wrap each invocation in a function statement and then call the function from * the top of the file. */ export default class JestHoistTransformer extends Transformer { __init() {this.hoistedFunctionNames = []} constructor( rootTransformer, tokens, nameManager, importProcessor, ) { super();this.rootTransformer = rootTransformer;this.tokens = tokens;this.nameManager = nameManager;this.importProcessor = importProcessor;JestHoistTransformer.prototype.__init.call(this);; } process() { if ( this.tokens.currentToken().scopeDepth === 0 && this.tokens.matches4(tt.name, tt.dot, tt.name, tt.parenL) && this.tokens.identifierName() === JEST_GLOBAL_NAME ) { // TODO: This only works if imports transform is active, which it will be for jest. // But if jest adds module support and we no longer need the import transform, this needs fixing. if (_optionalChain([this, 'access', _ => _.importProcessor, 'optionalAccess', _2 => _2.getGlobalNames, 'call', _3 => _3(), 'optionalAccess', _4 => _4.has, 'call', _5 => _5(JEST_GLOBAL_NAME)])) { return false; } return this.extractHoistedCalls(); } return false; } getHoistedCode() { if (this.hoistedFunctionNames.length > 0) { // This will be placed before module interop code, but that's fine since // imports aren't allowed in module mock factories. return this.hoistedFunctionNames.map((name) => `${name}();`).join(""); } return ""; } /** * Extracts any methods calls on the jest-object that should be hoisted. * * According to the jest docs, https://jestjs.io/docs/en/jest-object#jestmockmodulename-factory-options, * mock, unmock, enableAutomock, disableAutomock, are the methods that should be hoisted. * * We do not apply the same checks of the arguments as babel-plugin-jest-hoist does. */ extractHoistedCalls() { // We're handling a chain of calls where `jest` may or may not need to be inserted for each call // in the chain, so remove the initial `jest` to make the loop implementation cleaner. this.tokens.removeToken(); // Track some state so that multiple non-hoisted chained calls in a row keep their chaining // syntax. let followsNonHoistedJestCall = false; // Iterate through all chained calls on the jest object. while (this.tokens.matches3(tt.dot, tt.name, tt.parenL)) { const methodName = this.tokens.identifierNameAtIndex(this.tokens.currentIndex() + 1); const shouldHoist = HOISTED_METHODS.includes(methodName); if (shouldHoist) { // We've matched e.g. `.mock(...)` or similar call. // Replace the initial `.` with `function __jestHoist(){jest.` const hoistedFunctionName = this.nameManager.claimFreeName("__jestHoist"); this.hoistedFunctionNames.push(hoistedFunctionName); this.tokens.replaceToken(`function ${hoistedFunctionName}(){${JEST_GLOBAL_NAME}.`); this.tokens.copyToken(); this.tokens.copyToken(); this.rootTransformer.processBalancedCode(); this.tokens.copyExpectedToken(tt.parenR); this.tokens.appendCode(";}"); followsNonHoistedJestCall = false; } else { // This is a non-hoisted method, so just transform the code as usual. if (followsNonHoistedJestCall) { // If we didn't hoist the previous call, we can leave the code as-is to chain off of the // previous method call. It's important to preserve the code here because we don't know // for sure that the method actually returned the jest object for chaining. this.tokens.copyToken(); } else { // If we hoisted the previous call, we know it returns the jest object back, so we insert // the identifier `jest` to continue the chain. this.tokens.replaceToken(`${JEST_GLOBAL_NAME}.`); } this.tokens.copyToken(); this.tokens.copyToken(); this.rootTransformer.processBalancedCode(); this.tokens.copyExpectedToken(tt.parenR); followsNonHoistedJestCall = true; } } return true; } }