/** @license React v0.9.0 * react-refresh-babel.development.js * * Copyright (c) Facebook, Inc. and its affiliates. * * This source code is licensed under the MIT license found in the * LICENSE file in the root directory of this source tree. */ 'use strict'; if (process.env.NODE_ENV !== "production") { (function() { 'use strict'; function ReactFreshBabelPlugin (babel) { var opts = arguments.length > 1 && arguments[1] !== undefined ? arguments[1] : {}; if (typeof babel.env === 'function') { // Only available in Babel 7. var env = babel.env(); if (env !== 'development' && !opts.skipEnvCheck) { throw new Error('React Refresh Babel transform should only be enabled in development environment. ' + 'Instead, the environment is: "' + env + '". If you want to override this check, pass {skipEnvCheck: true} as plugin options.'); } } var t = babel.types; var refreshReg = t.identifier(opts.refreshReg || '$RefreshReg$'); var refreshSig = t.identifier(opts.refreshSig || '$RefreshSig$'); var registrationsByProgramPath = new Map(); function createRegistration(programPath, persistentID) { var handle = programPath.scope.generateUidIdentifier('c'); if (!registrationsByProgramPath.has(programPath)) { registrationsByProgramPath.set(programPath, []); } var registrations = registrationsByProgramPath.get(programPath); registrations.push({ handle: handle, persistentID: persistentID }); return handle; } function isComponentishName(name) { return typeof name === 'string' && name[0] >= 'A' && name[0] <= 'Z'; } function findInnerComponents(inferredName, path, callback) { var node = path.node; switch (node.type) { case 'Identifier': { if (!isComponentishName(node.name)) { return false; } // export default hoc(Foo) // const X = hoc(Foo) callback(inferredName, node, null); return true; } case 'FunctionDeclaration': { // function Foo() {} // export function Foo() {} // export default function Foo() {} callback(inferredName, node.id, null); return true; } case 'ArrowFunctionExpression': { if (node.body.type === 'ArrowFunctionExpression') { return false; } // let Foo = () => {} // export default hoc1(hoc2(() => {})) callback(inferredName, node, path); return true; } case 'FunctionExpression': { // let Foo = function() {} // const Foo = hoc1(forwardRef(function renderFoo() {})) // export default memo(function() {}) callback(inferredName, node, path); return true; } case 'CallExpression': { var argsPath = path.get('arguments'); if (argsPath === undefined || argsPath.length === 0) { return false; } var calleePath = path.get('callee'); switch (calleePath.node.type) { case 'MemberExpression': case 'Identifier': { var calleeSource = calleePath.getSource(); var firstArgPath = argsPath[0]; var innerName = inferredName + '$' + calleeSource; var foundInside = findInnerComponents(innerName, firstArgPath, callback); if (!foundInside) { return false; } // const Foo = hoc1(hoc2(() => {})) // export default memo(React.forwardRef(function() {})) callback(inferredName, node, path); return true; } default: { return false; } } } case 'VariableDeclarator': { var init = node.init; if (init === null) { return false; } var name = node.id.name; if (!isComponentishName(name)) { return false; } switch (init.type) { case 'ArrowFunctionExpression': case 'FunctionExpression': // Likely component definitions. break; case 'CallExpression': { // Maybe a HOC. // Try to determine if this is some form of import. var callee = init.callee; var calleeType = callee.type; if (calleeType === 'Import') { return false; } else if (calleeType === 'Identifier') { if (callee.name.indexOf('require') === 0) { return false; } else if (callee.name.indexOf('import') === 0) { return false; } // Neither require nor import. Might be a HOC. // Pass through. } break; } case 'TaggedTemplateExpression': // Maybe something like styled.div`...` break; default: return false; } var initPath = path.get('init'); var _foundInside = findInnerComponents(inferredName, initPath, callback); if (_foundInside) { return true; } // See if this identifier is used in JSX. Then it's a component. var binding = path.scope.getBinding(name); if (binding === undefined) { return; } var isLikelyUsedAsType = false; var referencePaths = binding.referencePaths; for (var i = 0; i < referencePaths.length; i++) { var ref = referencePaths[i]; if (ref.node && ref.node.type !== 'JSXIdentifier' && ref.node.type !== 'Identifier') { continue; } var refParent = ref.parent; if (refParent.type === 'JSXOpeningElement') { isLikelyUsedAsType = true; } else if (refParent.type === 'CallExpression') { var _callee = refParent.callee; var fnName = void 0; switch (_callee.type) { case 'Identifier': fnName = _callee.name; break; case 'MemberExpression': fnName = _callee.property.name; break; } switch (fnName) { case 'createElement': case 'jsx': case 'jsxDEV': case 'jsxs': isLikelyUsedAsType = true; break; } } if (isLikelyUsedAsType) { // const X = ... + later callback(inferredName, init, initPath); return true; } } } } return false; } function isBuiltinHook(hookName) { switch (hookName) { case 'useState': case 'React.useState': case 'useReducer': case 'React.useReducer': case 'useEffect': case 'React.useEffect': case 'useLayoutEffect': case 'React.useLayoutEffect': case 'useMemo': case 'React.useMemo': case 'useCallback': case 'React.useCallback': case 'useRef': case 'React.useRef': case 'useContext': case 'React.useContext': case 'useImperativeMethods': case 'React.useImperativeMethods': case 'useDebugValue': case 'React.useDebugValue': return true; default: return false; } } function getHookCallsSignature(functionNode) { var fnHookCalls = hookCalls.get(functionNode); if (fnHookCalls === undefined) { return null; } return { key: fnHookCalls.map(function (call) { return call.name + '{' + call.key + '}'; }).join('\n'), customHooks: fnHookCalls.filter(function (call) { return !isBuiltinHook(call.name); }).map(function (call) { return t.cloneDeep(call.callee); }) }; } var hasForceResetCommentByFile = new WeakMap(); // We let user do /* @refresh reset */ to reset state in the whole file. function hasForceResetComment(path) { var file = path.hub.file; var hasForceReset = hasForceResetCommentByFile.get(file); if (hasForceReset !== undefined) { return hasForceReset; } hasForceReset = false; var comments = file.ast.comments; for (var i = 0; i < comments.length; i++) { var cmt = comments[i]; if (cmt.value.indexOf('@refresh reset') !== -1) { hasForceReset = true; break; } } hasForceResetCommentByFile.set(file, hasForceReset); return hasForceReset; } function createArgumentsForSignature(node, signature, scope) { var key = signature.key, customHooks = signature.customHooks; var forceReset = hasForceResetComment(scope.path); var customHooksInScope = []; customHooks.forEach(function (callee) { // Check if a corresponding binding exists where we emit the signature. var bindingName; switch (callee.type) { case 'MemberExpression': if (callee.object.type === 'Identifier') { bindingName = callee.object.name; } break; case 'Identifier': bindingName = callee.name; break; } if (scope.hasBinding(bindingName)) { customHooksInScope.push(callee); } else { // We don't have anything to put in the array because Hook is out of scope. // Since it could potentially have been edited, remount the component. forceReset = true; } }); var finalKey = key; if (typeof require === 'function' && !opts.emitFullSignatures) { // Prefer to hash when we can (e.g. outside of ASTExplorer). // This makes it deterministically compact, even if there's // e.g. a useState initializer with some code inside. // We also need it for www that has transforms like cx() // that don't understand if something is part of a string. finalKey = require('crypto').createHash('sha1').update(key).digest('base64'); } var args = [node, t.stringLiteral(finalKey)]; if (forceReset || customHooksInScope.length > 0) { args.push(t.booleanLiteral(forceReset)); } if (customHooksInScope.length > 0) { args.push( // TODO: We could use an arrow here to be more compact. // However, don't do it until AMA can run them natively. t.functionExpression(null, [], t.blockStatement([t.returnStatement(t.arrayExpression(customHooksInScope))]))); } return args; } var seenForRegistration = new WeakSet(); var seenForSignature = new WeakSet(); var seenForOutro = new WeakSet(); var hookCalls = new WeakMap(); var HookCallsVisitor = { CallExpression: function (path) { var node = path.node; var callee = node.callee; // Note: this visitor MUST NOT mutate the tree in any way. // It runs early in a separate traversal and should be very fast. var name = null; switch (callee.type) { case 'Identifier': name = callee.name; break; case 'MemberExpression': name = callee.property.name; break; } if (name === null || !/^use[A-Z]/.test(name)) { return; } var fnScope = path.scope.getFunctionParent(); if (fnScope === null) { return; } // This is a Hook call. Record it. var fnNode = fnScope.block; if (!hookCalls.has(fnNode)) { hookCalls.set(fnNode, []); } var hookCallsForFn = hookCalls.get(fnNode); var key = ''; if (path.parent.type === 'VariableDeclarator') { // TODO: if there is no LHS, consider some other heuristic. key = path.parentPath.get('id').getSource(); } // Some built-in Hooks reset on edits to arguments. var args = path.get('arguments'); if (name === 'useState' && args.length > 0) { // useState second argument is initial state. key += '(' + args[0].getSource() + ')'; } else if (name === 'useReducer' && args.length > 1) { // useReducer second argument is initial state. key += '(' + args[1].getSource() + ')'; } hookCallsForFn.push({ callee: path.node.callee, name: name, key: key }); } }; return { visitor: { ExportDefaultDeclaration: function (path) { var node = path.node; var decl = node.declaration; var declPath = path.get('declaration'); if (decl.type !== 'CallExpression') { // For now, we only support possible HOC calls here. // Named function declarations are handled in FunctionDeclaration. // Anonymous direct exports like export default function() {} // are currently ignored. return; } // Make sure we're not mutating the same tree twice. // This can happen if another Babel plugin replaces parents. if (seenForRegistration.has(node)) { return; } seenForRegistration.add(node); // Don't mutate the tree above this point. // This code path handles nested cases like: // export default memo(() => {}) // In those cases it is more plausible people will omit names // so they're worth handling despite possible false positives. // More importantly, it handles the named case: // export default memo(function Named() {}) var inferredName = '%default%'; var programPath = path.parentPath; findInnerComponents(inferredName, declPath, function (persistentID, targetExpr, targetPath) { if (targetPath === null) { // For case like: // export default hoc(Foo) // we don't want to wrap Foo inside the call. // Instead we assume it's registered at definition. return; } var handle = createRegistration(programPath, persistentID); targetPath.replaceWith(t.assignmentExpression('=', handle, targetExpr)); }); }, FunctionDeclaration: { enter: function (path) { var node = path.node; var programPath; var insertAfterPath; switch (path.parent.type) { case 'Program': insertAfterPath = path; programPath = path.parentPath; break; case 'ExportNamedDeclaration': insertAfterPath = path.parentPath; programPath = insertAfterPath.parentPath; break; case 'ExportDefaultDeclaration': insertAfterPath = path.parentPath; programPath = insertAfterPath.parentPath; break; default: return; } var id = node.id; if (id === null) { // We don't currently handle anonymous default exports. return; } var inferredName = id.name; if (!isComponentishName(inferredName)) { return; } // Make sure we're not mutating the same tree twice. // This can happen if another Babel plugin replaces parents. if (seenForRegistration.has(node)) { return; } seenForRegistration.add(node); // Don't mutate the tree above this point. // export function Named() {} // function Named() {} findInnerComponents(inferredName, path, function (persistentID, targetExpr) { var handle = createRegistration(programPath, persistentID); insertAfterPath.insertAfter(t.expressionStatement(t.assignmentExpression('=', handle, targetExpr))); }); }, exit: function (path) { var node = path.node; var id = node.id; if (id === null) { return; } var signature = getHookCallsSignature(node); if (signature === null) { return; } // Make sure we're not mutating the same tree twice. // This can happen if another Babel plugin replaces parents. if (seenForSignature.has(node)) { return; } seenForSignature.add(node); // Don't mutate the tree above this point. var sigCallID = path.scope.generateUidIdentifier('_s'); path.scope.parent.push({ id: sigCallID, init: t.callExpression(refreshSig, []) }); // The signature call is split in two parts. One part is called inside the function. // This is used to signal when first render happens. path.get('body').unshiftContainer('body', t.expressionStatement(t.callExpression(sigCallID, []))); // The second call is around the function itself. // This is used to associate a type with a signature. // Unlike with $RefreshReg$, this needs to work for nested // declarations too. So we need to search for a path where // we can insert a statement rather than hard coding it. var insertAfterPath = null; path.find(function (p) { if (p.parentPath.isBlock()) { insertAfterPath = p; return true; } }); if (insertAfterPath === null) { return; } insertAfterPath.insertAfter(t.expressionStatement(t.callExpression(sigCallID, createArgumentsForSignature(id, signature, insertAfterPath.scope)))); } }, 'ArrowFunctionExpression|FunctionExpression': { exit: function (path) { var node = path.node; var signature = getHookCallsSignature(node); if (signature === null) { return; } // Make sure we're not mutating the same tree twice. // This can happen if another Babel plugin replaces parents. if (seenForSignature.has(node)) { return; } seenForSignature.add(node); // Don't mutate the tree above this point. var sigCallID = path.scope.generateUidIdentifier('_s'); path.scope.parent.push({ id: sigCallID, init: t.callExpression(refreshSig, []) }); // The signature call is split in two parts. One part is called inside the function. // This is used to signal when first render happens. if (path.node.body.type !== 'BlockStatement') { path.node.body = t.blockStatement([t.returnStatement(path.node.body)]); } path.get('body').unshiftContainer('body', t.expressionStatement(t.callExpression(sigCallID, []))); // The second call is around the function itself. // This is used to associate a type with a signature. if (path.parent.type === 'VariableDeclarator') { var insertAfterPath = null; path.find(function (p) { if (p.parentPath.isBlock()) { insertAfterPath = p; return true; } }); if (insertAfterPath === null) { return; } // Special case when a function would get an inferred name: // let Foo = () => {} // let Foo = function() {} // We'll add signature it on next line so that // we don't mess up the inferred 'Foo' function name. insertAfterPath.insertAfter(t.expressionStatement(t.callExpression(sigCallID, createArgumentsForSignature(path.parent.id, signature, insertAfterPath.scope)))); // Result: let Foo = () => {}; __signature(Foo, ...); } else { // let Foo = hoc(() => {}) path.replaceWith(t.callExpression(sigCallID, createArgumentsForSignature(node, signature, path.scope))); // Result: let Foo = hoc(__signature(() => {}, ...)) } } }, VariableDeclaration: function (path) { var node = path.node; var programPath; var insertAfterPath; switch (path.parent.type) { case 'Program': insertAfterPath = path; programPath = path.parentPath; break; case 'ExportNamedDeclaration': insertAfterPath = path.parentPath; programPath = insertAfterPath.parentPath; break; case 'ExportDefaultDeclaration': insertAfterPath = path.parentPath; programPath = insertAfterPath.parentPath; break; default: return; } // Make sure we're not mutating the same tree twice. // This can happen if another Babel plugin replaces parents. if (seenForRegistration.has(node)) { return; } seenForRegistration.add(node); // Don't mutate the tree above this point. var declPaths = path.get('declarations'); if (declPaths.length !== 1) { return; } var declPath = declPaths[0]; var inferredName = declPath.node.id.name; findInnerComponents(inferredName, declPath, function (persistentID, targetExpr, targetPath) { if (targetPath === null) { // For case like: // export const Something = hoc(Foo) // we don't want to wrap Foo inside the call. // Instead we assume it's registered at definition. return; } var handle = createRegistration(programPath, persistentID); if (targetPath.parent.type === 'VariableDeclarator') { // Special case when a variable would get an inferred name: // let Foo = () => {} // let Foo = function() {} // let Foo = styled.div``; // We'll register it on next line so that // we don't mess up the inferred 'Foo' function name. // (eg: with @babel/plugin-transform-react-display-name or // babel-plugin-styled-components) insertAfterPath.insertAfter(t.expressionStatement(t.assignmentExpression('=', handle, declPath.node.id))); // Result: let Foo = () => {}; _c1 = Foo; } else { // let Foo = hoc(() => {}) targetPath.replaceWith(t.assignmentExpression('=', handle, targetExpr)); // Result: let Foo = hoc(_c1 = () => {}) } }); }, Program: { enter: function (path) { // This is a separate early visitor because we need to collect Hook calls // and "const [foo, setFoo] = ..." signatures before the destructuring // transform mangles them. This extra traversal is not ideal for perf, // but it's the best we can do until we stop transpiling destructuring. path.traverse(HookCallsVisitor); }, exit: function (path) { var registrations = registrationsByProgramPath.get(path); if (registrations === undefined) { return; } // Make sure we're not mutating the same tree twice. // This can happen if another Babel plugin replaces parents. var node = path.node; if (seenForOutro.has(node)) { return; } seenForOutro.add(node); // Don't mutate the tree above this point. registrationsByProgramPath.delete(path); var declarators = []; path.pushContainer('body', t.variableDeclaration('var', declarators)); registrations.forEach(function (_ref) { var handle = _ref.handle, persistentID = _ref.persistentID; path.pushContainer('body', t.expressionStatement(t.callExpression(refreshReg, [handle, t.stringLiteral(persistentID)]))); declarators.push(t.variableDeclarator(handle)); }); } } } }; } module.exports = ReactFreshBabelPlugin; })(); }