Files
babel/src/babel/traversal/scope.js

765 lines
18 KiB
JavaScript

import includes from "lodash/collection/includes";
import explode from "./explode";
import traverse from "./index";
import defaults from "lodash/object/defaults";
import * as messages from "../messages";
import Binding from "./binding";
import globals from "globals";
import flatten from "lodash/array/flatten";
import extend from "lodash/object/extend";
import object from "../helpers/object";
import each from "lodash/collection/each";
import * as t from "../types";
var functionVariableVisitor = {
enter(node, parent, scope, state) {
if (t.isFor(node)) {
each(t.FOR_INIT_KEYS, (key) => {
var declar = this.get(key);
if (declar.isVar()) state.scope.registerBinding("var", declar);
});
}
// this block is a function so we'll stop since none of the variables
// declared within are accessible
if (this.isFunction()) return this.skip();
// function identifier doesn't belong to this scope
if (state.blockId && node === state.blockId) return;
// delegate block scope handling to the `blockVariableVisitor`
if (this.isBlockScoped()) return;
// this will be hit again once we traverse into it after this iteration
if (this.isExportDeclaration() && t.isDeclaration(node.declaration)) return;
// we've ran into a declaration!
if (this.isDeclaration()) state.scope.registerDeclaration(this);
}
};
var programReferenceVisitor = {
enter(node, parent, scope, state) {
if (t.isReferencedIdentifier(node, parent) && !scope.hasBinding(node.name)) {
state.addGlobal(node);
} else if (t.isLabeledStatement(node)) {
state.addGlobal(node);
} else if (t.isAssignmentExpression(node)) {
scope.registerConstantViolation(this.get("left"), this.get("right"));
} else if (t.isUpdateExpression(node)) {
scope.registerConstantViolation(this.get("argument"), null);
} else if (t.isUnaryExpression(node) && node.operator === "delete") {
scope.registerConstantViolation(this.get("left"), null);
}
}
};
var blockVariableVisitor = {
enter(node, parent, scope, state) {
if (this.isFunctionDeclaration() || this.isBlockScoped()) {
state.registerDeclaration(this);
}
if (this.isScope()) {
this.skip();
}
}
};
var renameVisitor = explode({
Identifier(node, parent, scope, state) {
if (this.isReferenced() && node.name === state.oldName) {
if (this.parentPath.isProperty() && this.key === "key" && parent.shorthand) {
parent.shorthand = false;
parent.value = t.identifier(state.newName);
} else {
node.name = state.newName;
}
}
},
Declaration(node, parent, scope, state) {
var ids = {};
var matchesLocal = (node, key) => {
return node.local === node[key] && (node.local.name === state.oldName || node.local.name === state.newName);
};
if (this.isExportDeclaration() && this.has("specifiers")) {
var specifiers = this.get("specifiers");
for (var specifier of (specifiers: Array)) {
if (specifier.isExportSpecifier() && matchesLocal(specifier.node, "exported")) {
specifier.get("exported").replaceWith(t.identifier(state.oldName));
}
}
} else if (this.isImportDeclaration() && this.has("specifiers")) {
var specifiers = this.get("specifiers");
for (var specifier of (specifiers: Array)) {
if (specifier.isImportSpecifier() && matchesLocal(specifier.node, "imported")) {
state.binding = state.info.identifier = t.identifier(state.newName);
specifier.get("local").replaceWith(state.binding);
} else {
extend(ids, specifier.getBindingIdentifiers());
}
}
} else {
ids = this.getBindingIdentifiers();
}
for (var name in ids) {
if (name === state.oldName) ids[name].name = state.newName;
}
},
Scopable(node, parent, scope, state) {
if (this.isScope()) {
if (!scope.bindingIdentifierEquals(state.oldName, state.binding)) {
this.skip();
}
}
}
});
export default class Scope {
/**
* This searches the current "scope" and collects all references/bindings
* within.
*/
constructor(path: TraversalPath, parent?: Scope, file?: File) {
if (parent && parent.block === path.node) {
return parent;
}
var cached = path.getData("scope");
if (cached && cached.parent === parent) {
return cached;
} else {
//path.setData("scope", this);
}
this.parent = parent;
this.file = parent ? parent.file : file;
this.parentBlock = path.parent;
this.block = path.node;
this.path = path;
this.crawl();
}
static globals = flatten([globals.builtin, globals.browser, globals.node].map(Object.keys));
static contextVariables = ["this", "arguments", "super"];
/**
* Description
*/
traverse(node: Object, opts: Object, state?) {
traverse(node, opts, this, state, this.path);
}
/**
* Description
*/
generateTemp(name: string = "temp") {
var id = this.generateUidIdentifier(name);
this.push({ id });
return id;
}
/**
* Description
*/
generateUidIdentifier(name: string) {
return t.identifier(this.generateUid(name));
}
/**
* Description
*/
generateUid(name: string) {
name = t.toIdentifier(name).replace(/^_+/, "");
var uid;
var i = 0;
do {
uid = this._generateUid(name, i);
i++;
} while (this.hasBinding(uid) || this.hasGlobal(uid) || this.hasUid(uid));
this.file.uids[uid] = true;
return uid;
}
_generateUid(name, i) {
var id = name;
if (i > 1) id += i;
return `_${id}`;
}
/**
* Description
*/
hasUid(name): boolean {
var scope = this;
do {
if (scope.file.uids[name]) return true;
scope = scope.parent;
} while (scope);
return false;
}
/*
* Description
*/
generateUidBasedOnNode(parent: Object, defaultName?: String): Object {
var node = parent;
if (t.isAssignmentExpression(parent)) {
node = parent.left;
} else if (t.isVariableDeclarator(parent)) {
node = parent.id;
} else if (t.isProperty(node)) {
node = node.key;
}
var parts = [];
var add = function (node) {
if (t.isModuleDeclaration(node)) {
if (node.specifiers && node.specifiers.length) {
for (var i = 0; i < node.specifiers.length; i++) {
add(node.specifiers[i]);
}
} else {
add(node.source);
}
} else if (t.isModuleSpecifier(node)) {
add(node.local);
} else if (t.isMemberExpression(node)) {
add(node.object);
add(node.property);
} else if (t.isIdentifier(node)) {
parts.push(node.name);
} else if (t.isLiteral(node)) {
parts.push(node.value);
} else if (t.isCallExpression(node)) {
add(node.callee);
} else if (t.isObjectExpression(node) || t.isObjectPattern(node)) {
for (var i = 0; i < node.properties.length; i++) {
var prop = node.properties[i];
add(prop.key || prop.argument);
}
}
};
add(node);
var id = parts.join("$");
id = id.replace(/^_/, "") || defaultName || "ref";
return this.generateUidIdentifier(id);
}
/**
* Description
*/
generateMemoisedReference(node: Object, dontPush?: boolean): ?Object {
if (t.isThisExpression(node) || t.isSuper(node)) {
return null;
}
if (t.isIdentifier(node) && this.hasBinding(node.name)) {
return null;
}
var id = this.generateUidBasedOnNode(node);
if (!dontPush) this.push({ id });
return id;
}
/**
* Description
*/
checkBlockScopedCollisions(kind: string, name: string, id: Object) {
var local = this.getOwnBindingInfo(name);
if (!local) return;
if (kind === "param") return;
if (kind === "hoisted" && local.kind === "let") return;
var duplicate = false;
if (!duplicate) duplicate = kind === "let" || kind === "const" || local.kind === "let" || local.kind === "const" || local.kind === "module";
if (!duplicate) duplicate = local.kind === "param" && (kind === "let" || kind === "const");
if (duplicate) {
throw this.file.errorWithNode(id, messages.get("scopeDuplicateDeclaration", name), TypeError);
}
}
/**
* Description
*/
rename(oldName: string, newName: string, block?) {
newName = newName || this.generateUidIdentifier(oldName).name;
var info = this.getBinding(oldName);
if (!info) return;
var state = {
newName: newName,
oldName: oldName,
binding: info.identifier,
info: info
};
var scope = info.scope;
scope.traverse(block || scope.block, renameVisitor, state);
if (!block) {
scope.removeOwnBinding(oldName);
scope.bindings[newName] = info;
state.binding.name = newName;
}
var file = this.file;
if (file) {
this._renameFromMap(file.moduleFormatter.localImports, oldName, newName, state.binding);
//this._renameFromMap(file.moduleFormatter.localExports, oldName, newName);
}
}
_renameFromMap(map, oldName, newName, value) {
if (map[oldName]) {
map[newName] = value;
map[oldName] = null;
}
}
/**
* Description
*/
dump() {
var scope = this;
do {
console.log(scope.block.type, "Bindings:", Object.keys(scope.bindings));
} while(scope = scope.parent);
console.log("-------------");
}
/**
* Description
*/
toArray(node: Object, i?: number) {
var file = this.file;
if (t.isIdentifier(node)) {
var binding = this.getBinding(node.name);
if (binding && binding.isTypeGeneric("Array", { inference: false })) return node;
}
if (t.isArrayExpression(node)) {
return node;
}
if (t.isIdentifier(node, { name: "arguments" })) {
return t.callExpression(t.memberExpression(file.addHelper("slice"), t.identifier("call")), [node]);
}
var helperName = "to-array";
var args = [node];
if (i === true) {
helperName = "to-consumable-array";
} else if (i) {
args.push(t.literal(i));
helperName = "sliced-to-array";
if (this.file.isLoose("es6.forOf")) helperName += "-loose";
}
return t.callExpression(file.addHelper(helperName), args);
}
/**
* Description
*/
registerDeclaration(path: TraversalPath) {
var node = path.node;
if (t.isFunctionDeclaration(node)) {
this.registerBinding("hoisted", path);
} else if (t.isVariableDeclaration(node)) {
var declarations = path.get("declarations");
for (var i = 0; i < declarations.length; i++) {
this.registerBinding(node.kind, declarations[i]);
}
} else if (t.isClassDeclaration(node)) {
this.registerBinding("let", path);
} else if (t.isImportDeclaration(node) || t.isExportDeclaration(node)) {
this.registerBinding("module", path);
} else {
this.registerBinding("unknown", path);
}
}
/**
* Description
*/
registerConstantViolation(left: TraversalPath, right: TraversalPath) {
var ids = left.getBindingIdentifiers();
for (var name in ids) {
var binding = this.getBinding(name);
if (!binding) continue;
if (right) {
var rightType = right.typeAnnotation;
if (rightType && binding.isCompatibleWithType(rightType)) continue;
}
binding.reassign();
}
}
/**
* Description
*/
registerBinding(kind: string, path: TraversalPath) {
if (!kind) throw new ReferenceError("no `kind`");
var ids = path.getBindingIdentifiers();
for (var name in ids) {
var id = ids[name];
this.checkBlockScopedCollisions(kind, name, id);
this.bindings[name] = new Binding({
identifier: id,
scope: this,
path: path,
kind: kind
});
}
}
/**
* Description
*/
addGlobal(node: Object) {
this.globals[node.name] = node;
}
/**
* Description
*/
hasGlobal(name: string): boolean {
var scope = this;
do {
if (scope.globals[name]) return true;
} while (scope = scope.parent);
return false;
}
/**
* Description
*/
recrawl() {
this.path.setData("scopeInfo", null);
this.crawl();
}
/**
* Description
*/
crawl() {
var path = this.path;
//
var info = this.block._scopeInfo;
if (info) return extend(this, info);
info = this.block._scopeInfo = {
bindings: object(),
globals: object()
};
extend(this, info);
// ForStatement - left, init
if (path.isLoop()) {
for (let i = 0; i < t.FOR_INIT_KEYS.length; i++) {
var node = path.get(t.FOR_INIT_KEYS[i]);
if (node.isBlockScoped()) this.registerBinding(node.node.kind, node);
}
}
// FunctionExpression - id
if (path.isFunctionExpression() && path.has("id")) {
if (!t.isProperty(path.parent, { method: true })) {
this.registerBinding("var", path.get("id"));
}
}
// Class
if (path.isClass() && path.has("id")) {
this.registerBinding("var", path.get("id"));
}
// Function - params, rest
if (path.isFunction()) {
var params = path.get("params");
for (let i = 0; i < params.length; i++) {
this.registerBinding("param", params[i]);
}
this.traverse(path.get("body").node, blockVariableVisitor, this);
}
// Program, Function - var variables
if (path.isProgram() || path.isFunction()) {
this.traverse(path.node, functionVariableVisitor, {
blockId: path.get("id").node,
scope: this
});
}
// Program, BlockStatement, Function - let variables
if (path.isBlockStatement() || path.isProgram()) {
this.traverse(path.node, blockVariableVisitor, this);
}
// CatchClause - param
if (path.isCatchClause()) {
this.registerBinding("let", path.get("param"));
}
// ComprehensionExpression - blocks
if (path.isComprehensionExpression()) {
this.registerBinding("let", path);
}
// Program
if (path.isProgram()) {
this.traverse(path.node, programReferenceVisitor, this);
}
}
/**
* Description
*/
push(opts: Object) {
var path = this.path;
if (path.isLoop() || path.isCatchClause() || path.isFunction()) {
t.ensureBlock(path.node);
path = path.get("body");
}
if (!path.isBlockStatement() && !path.isProgram()) {
path = this.getBlockParent().path;
}
var unique = opts.unique;
var kind = opts.kind || "var";
var dataKey = `declaration:${kind}`;
var declar = !unique && path.getData(dataKey);
if (!declar) {
declar = t.variableDeclaration(opts.kind || "var", []);
declar._generated = true;
declar._blockHoist = 2;
this.file.attachAuxiliaryComment(declar);
path.get("body")[0]._containerInsertBefore([declar]);
if (!unique) path.setData(dataKey, declar);
}
declar.declarations.push(t.variableDeclarator(opts.id, opts.init));
}
/**
* Walk up the scope tree until we hit either a Function or reach the
* very top and hit Program.
*/
getFunctionParent() {
var scope = this;
while (scope.parent && !t.isFunction(scope.block)) {
scope = scope.parent;
}
return scope;
}
/**
* Walk up the scope tree until we hit either a BlockStatement/Loop or reach the
* very top and hit Program.
*/
getBlockParent() {
var scope = this;
while (scope.parent && !t.isFunction(scope.block) && !t.isLoop(scope.block) && !t.isFunction(scope.block)) {
scope = scope.parent;
}
return scope;
}
/**
* Walks the scope tree and gathers **all** bindings.
*/
getAllBindings(): Object {
var ids = object();
var scope = this;
do {
defaults(ids, scope.bindings);
scope = scope.parent;
} while (scope);
return ids;
}
/**
* Walks the scope tree and gathers all declarations of `kind`.
*/
getAllBindingsOfKind(): Object {
var ids = object();
for (let i = 0; i < arguments.length; i++) {
var kind = arguments[i];
var scope = this;
do {
for (var name in scope.bindings) {
var binding = scope.bindings[name];
if (binding.kind === kind) ids[name] = binding;
}
scope = scope.parent;
} while (scope);
}
return ids;
}
/**
* Description
*/
bindingIdentifierEquals(name: string, node: Object): boolean {
return this.getBindingIdentifier(name) === node;
}
/**
* Description
*/
getBinding(name: string) {
var scope = this;
do {
var binding = scope.getOwnBindingInfo(name);
if (binding) return binding;
} while (scope = scope.parent);
}
/**
* Description
*/
getOwnBindingInfo(name: string) {
return this.bindings[name];
}
/**
* Description
*/
getBindingIdentifier(name: string) {
var info = this.getBinding(name);
return info && info.identifier;
}
/**
* Description
*/
getOwnBindingIdentifier(name: string) {
var binding = this.bindings[name];
return binding && binding.identifier;
}
/**
* Description
*/
hasOwnBinding(name: string) {
return !!this.getOwnBindingInfo(name);
}
/**
* Description
*/
hasBinding(name: string) {
if (!name) return false;
if (this.hasOwnBinding(name)) return true;
if (this.parentHasBinding(name)) return true;
if (this.file.uids[name]) return true;
if (includes(Scope.globals, name)) return true;
if (includes(Scope.contextVariables, name)) return true;
return false;
}
/**
* Description
*/
parentHasBinding(name: string) {
return this.parent && this.parent.hasBinding(name);
}
/**
* Description
*/
removeOwnBinding(name: string) {
delete this.bindings[name];
}
/**
* Description
*/
removeBinding(name: string) {
var info = this.getBinding(name);
if (info) info.scope.removeOwnBinding(name);
}
}