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/* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */
"use strict";
const Babel = require("./babel");
const _path = require("path");
function isRequire(t, node) {
return node && t.isCallExpression(node) && node.callee.name == "require";
}
function shouldLazyLoad(value) {
return (
!value.includes("codemirror/") &&
!value.endsWith(".properties") &&
!value.startsWith("devtools/") &&
!value.startsWith("resource://devtools/") &&
// XXX: the lazyRequire rewriter (in transformMC) fails for this module, it
// evaluates `t.thisExpression()` as `void 0` instead of `this`. But the
// rewriter still works for other call sites and seems mandatory for the
// debugger to start successfully (lazy requires help to break circular
// dependencies).
value !== "resource://gre/modules/AppConstants.jsm"
);
}
/**
* This Babel plugin is used to transpile a single Debugger module into a module that
* can be loaded in Firefox via the regular DevTools loader.
*/
function transformMC({ types: t }) {
return {
visitor: {
StringLiteral(path, state) {
const { filePath } = state.opts;
let value = path.node.value;
if (!isRequire(t, path.parent)) {
return;
}
if (shouldLazyLoad(value)) {
const requireCall = path.parentPath;
const declarator = requireCall.parentPath;
const declaration = declarator.parentPath;
// require()s that are not assigned to a variable cannot be safely lazily required
// since we lack anything to initiate the require (= the getter for the variable)
if (declarator.type !== "VariableDeclarator") {
return;
}
// update relative paths to be "absolute" (starting with devtools/)
// e.g. ./utils/source-queue
if (value.startsWith(".")) {
// Create full path
// e.g. z:\build\build\src\devtools\client\debugger\src\utils\source-queue
let newValue = _path.join(_path.dirname(filePath), value);
// Select the devtools portion of the path
// e.g. devtools\client\debugger\src\utils\source-queue
if (!newValue.startsWith("devtools")) {
newValue = newValue.match(/^(.*?)(devtools.*)/)[2];
}
// Replace forward slashes with back slashes
// e.g devtools/client/debugger/src/utils/source-queue
newValue = newValue.replace(/\\/g, "/");
value = newValue;
}
// rewrite to: loader.lazyRequireGetter(this, "variableName", "pathToFile")
const lazyRequire = t.callExpression(
t.memberExpression(
t.identifier("loader"),
t.identifier("lazyRequireGetter")
),
[
t.thisExpression(),
t.stringLiteral(declarator.node.id.name || ""),
t.stringLiteral(value),
]
);
declaration.replaceWith(lazyRequire);
}
},
},
};
}
Babel.registerPlugin("transform-mc", transformMC);
module.exports = function (filePath) {
return [
"proposal-class-properties",
"transform-modules-commonjs",
["transform-mc", { filePath }],
];
};
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