/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const forEachBail = require("./forEachBail");
const { PathType, getType } = require("./util/path");
/** @typedef {import("./Resolver")} Resolver */
/** @typedef {import("./Resolver").ResolveRequest} ResolveRequest */
/** @typedef {import("./Resolver").ResolveStepHook} ResolveStepHook */
/** @typedef {string | Array<string> | false} Alias */
/** @typedef {{alias: Alias, name: string, onlyModule?: boolean}} AliasOption */
module.exports = class AliasPlugin {
/**
* @param {string | ResolveStepHook} source source
* @param {AliasOption | Array<AliasOption>} options options
* @param {string | ResolveStepHook} target target
*/
constructor(source, options, target) {
this.source = source;
this.options = Array.isArray(options) ? options : [options];
this.target = target;
}
/**
* @param {Resolver} resolver the resolver
* @returns {void}
*/
apply(resolver) {
const target = resolver.ensureHook(this.target);
/**
* @param {string} maybeAbsolutePath path
* @returns {null|string} absolute path with slash ending
*/
const getAbsolutePathWithSlashEnding = maybeAbsolutePath => {
const type = getType(maybeAbsolutePath);
if (type === PathType.AbsolutePosix || type === PathType.AbsoluteWin) {
return resolver.join(maybeAbsolutePath, "_").slice(0, -1);
}
return null;
};
/**
* @param {string} path path
* @param {string} maybeSubPath sub path
* @returns {boolean} true, if path is sub path
*/
const isSubPath = (path, maybeSubPath) => {
const absolutePath = getAbsolutePathWithSlashEnding(maybeSubPath);
if (!absolutePath) return false;
return path.startsWith(absolutePath);
};
resolver
.getHook(this.source)
.tapAsync("AliasPlugin", (request, resolveContext, callback) => {
const innerRequest = request.request || request.path;
if (!innerRequest) return callback();
forEachBail(
this.options,
(item, callback) => {
/** @type {boolean} */
let shouldStop = false;
if (
innerRequest === item.name ||
(!item.onlyModule &&
(request.request
? innerRequest.startsWith(`${item.name}/`)
: isSubPath(innerRequest, item.name)))
) {
/** @type {string} */
const remainingRequest = innerRequest.slice(item.name.length);
/**
* @param {Alias} alias alias
* @param {(err?: null|Error, result?: null|ResolveRequest) => void} callback callback
* @returns {void}
*/
const resolveWithAlias = (alias, callback) => {
if (alias === false) {
/** @type {ResolveRequest} */
const ignoreObj = {
...request,
path: false
};
if (typeof resolveContext.yield === "function") {
resolveContext.yield(ignoreObj);
return callback(null, null);
}
return callback(null, ignoreObj);
}
if (
innerRequest !== alias &&
!innerRequest.startsWith(alias + "/")
) {
shouldStop = true;
const newRequestStr = alias + remainingRequest;
/** @type {ResolveRequest} */
const obj = {
...request,
request: newRequestStr,
fullySpecified: false
};
return resolver.doResolve(
target,
obj,
"aliased with mapping '" +
item.name +
"': '" +
alias +
"' to '" +
newRequestStr +
"'",
resolveContext,
(err, result) => {
if (err) return callback(err);
if (result) return callback(null, result);
return callback();
}
);
}
return callback();
};
/**
* @param {null|Error} [err] error
* @param {null|ResolveRequest} [result] result
* @returns {void}
*/
const stoppingCallback = (err, result) => {
if (err) return callback(err);
if (result) return callback(null, result);
// Don't allow other aliasing or raw request
if (shouldStop) return callback(null, null);
return callback();
};
if (Array.isArray(item.alias)) {
return forEachBail(
item.alias,
resolveWithAlias,
stoppingCallback
);
} else {
return resolveWithAlias(item.alias, stoppingCallback);
}
}
return callback();
},
callback
);
});
}
};