visitors.js
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"use strict";
Object.defineProperty(exports, "__esModule", {
value: true
});
exports.explode = explode;
exports.merge = merge;
exports.verify = verify;
var virtualTypes = require("./path/lib/virtual-types");
var _t = require("@babel/types");
const {
DEPRECATED_KEYS,
FLIPPED_ALIAS_KEYS,
TYPES
} = _t;
function isVirtualType(type) {
return type in virtualTypes;
}
function explode(visitor) {
if (visitor._exploded) return visitor;
visitor._exploded = true;
for (const nodeType of Object.keys(visitor)) {
if (shouldIgnoreKey(nodeType)) continue;
const parts = nodeType.split("|");
if (parts.length === 1) continue;
const fns = visitor[nodeType];
delete visitor[nodeType];
for (const part of parts) {
visitor[part] = fns;
}
}
verify(visitor);
delete visitor.__esModule;
ensureEntranceObjects(visitor);
ensureCallbackArrays(visitor);
for (const nodeType of Object.keys(visitor)) {
if (shouldIgnoreKey(nodeType)) continue;
if (!isVirtualType(nodeType)) continue;
const fns = visitor[nodeType];
for (const type of Object.keys(fns)) {
fns[type] = wrapCheck(nodeType, fns[type]);
}
delete visitor[nodeType];
const types = virtualTypes[nodeType];
if (types !== null) {
for (const type of types) {
if (visitor[type]) {
mergePair(visitor[type], fns);
} else {
visitor[type] = fns;
}
}
} else {
mergePair(visitor, fns);
}
}
for (const nodeType of Object.keys(visitor)) {
if (shouldIgnoreKey(nodeType)) continue;
const fns = visitor[nodeType];
let aliases = FLIPPED_ALIAS_KEYS[nodeType];
const deprecatedKey = DEPRECATED_KEYS[nodeType];
if (deprecatedKey) {
console.trace(`Visitor defined for ${nodeType} but it has been renamed to ${deprecatedKey}`);
aliases = [deprecatedKey];
}
if (!aliases) continue;
delete visitor[nodeType];
for (const alias of aliases) {
const existing = visitor[alias];
if (existing) {
mergePair(existing, fns);
} else {
visitor[alias] = Object.assign({}, fns);
}
}
}
for (const nodeType of Object.keys(visitor)) {
if (shouldIgnoreKey(nodeType)) continue;
ensureCallbackArrays(
visitor[nodeType]);
}
return visitor;
}
function verify(visitor) {
if (visitor._verified) return;
if (typeof visitor === "function") {
throw new Error("You passed `traverse()` a function when it expected a visitor object, " + "are you sure you didn't mean `{ enter: Function }`?");
}
for (const nodeType of Object.keys(visitor)) {
if (nodeType === "enter" || nodeType === "exit") {
validateVisitorMethods(nodeType, visitor[nodeType]);
}
if (shouldIgnoreKey(nodeType)) continue;
if (TYPES.indexOf(nodeType) < 0) {
throw new Error(`You gave us a visitor for the node type ${nodeType} but it's not a valid type`);
}
const visitors = visitor[nodeType];
if (typeof visitors === "object") {
for (const visitorKey of Object.keys(visitors)) {
if (visitorKey === "enter" || visitorKey === "exit") {
validateVisitorMethods(`${nodeType}.${visitorKey}`, visitors[visitorKey]);
} else {
throw new Error("You passed `traverse()` a visitor object with the property " + `${nodeType} that has the invalid property ${visitorKey}`);
}
}
}
}
visitor._verified = true;
}
function validateVisitorMethods(path, val) {
const fns = [].concat(val);
for (const fn of fns) {
if (typeof fn !== "function") {
throw new TypeError(`Non-function found defined in ${path} with type ${typeof fn}`);
}
}
}
function merge(visitors, states = [], wrapper) {
const rootVisitor = {};
for (let i = 0; i < visitors.length; i++) {
const visitor = visitors[i];
const state = states[i];
explode(visitor);
for (const type of Object.keys(visitor)) {
let visitorType = visitor[type];
if (state || wrapper) {
visitorType = wrapWithStateOrWrapper(visitorType, state, wrapper);
}
const nodeVisitor = rootVisitor[type] || (rootVisitor[type] = {});
mergePair(nodeVisitor, visitorType);
}
}
return rootVisitor;
}
function wrapWithStateOrWrapper(oldVisitor, state, wrapper) {
const newVisitor = {};
for (const key of Object.keys(oldVisitor)) {
let fns = oldVisitor[key];
if (!Array.isArray(fns)) continue;
fns = fns.map(function (fn) {
let newFn = fn;
if (state) {
newFn = function (path) {
return fn.call(state, path, state);
};
}
if (wrapper) {
newFn = wrapper(state.key, key, newFn);
}
if (newFn !== fn) {
newFn.toString = () => fn.toString();
}
return newFn;
});
newVisitor[key] = fns;
}
return newVisitor;
}
function ensureEntranceObjects(obj) {
for (const key of Object.keys(obj)) {
if (shouldIgnoreKey(key)) continue;
const fns = obj[key];
if (typeof fns === "function") {
obj[key] = {
enter: fns
};
}
}
}
function ensureCallbackArrays(obj) {
if (obj.enter && !Array.isArray(obj.enter)) obj.enter = [obj.enter];
if (obj.exit && !Array.isArray(obj.exit)) obj.exit = [obj.exit];
}
function wrapCheck(nodeType, fn) {
const newFn = function (path) {
if (path[`is${nodeType}`]()) {
return fn.apply(this, arguments);
}
};
newFn.toString = () => fn.toString();
return newFn;
}
function shouldIgnoreKey(key) {
if (key[0] === "_") return true;
if (key === "enter" || key === "exit" || key === "shouldSkip") return true;
if (key === "denylist" || key === "noScope" || key === "skipKeys" ||
key === "blacklist") {
return true;
}
return false;
}
function mergePair(dest, src) {
for (const key of Object.keys(src)) {
dest[key] = [].concat(dest[key] || [], src[key]);
}
}
//# sourceMappingURL=visitors.js.map