webpack/lib/UseStrictPlugin.js

56 lines
1.6 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const ConstDependency = require("./dependencies/ConstDependency");
/** @typedef {import("./Compiler")} Compiler */
class UseStrictPlugin {
/**
* @param {Compiler} compiler the compiler instance
* @returns {void}
*/
apply(compiler) {
compiler.hooks.compilation.tap(
"UseStrictPlugin",
(compilation, { normalModuleFactory }) => {
const handler = parser => {
parser.hooks.program.tap("UseStrictPlugin", ast => {
const firstNode = ast.body[0];
if (
firstNode &&
firstNode.type === "ExpressionStatement" &&
firstNode.expression.type === "Literal" &&
firstNode.expression.value === "use strict"
) {
// Remove "use strict" expression. It will be added later by the renderer again.
// This is necessary in order to not break the strict mode when webpack prepends code.
// @see https://github.com/webpack/webpack/issues/1970
const dep = new ConstDependency("", firstNode.range);
dep.loc = firstNode.loc;
parser.state.module.addPresentationalDependency(dep);
parser.state.module.buildInfo.strict = true;
}
});
};
normalModuleFactory.hooks.parser
.for("javascript/auto")
.tap("UseStrictPlugin", handler);
normalModuleFactory.hooks.parser
.for("javascript/dynamic")
.tap("UseStrictPlugin", handler);
normalModuleFactory.hooks.parser
.for("javascript/esm")
.tap("UseStrictPlugin", handler);
}
);
}
}
module.exports = UseStrictPlugin;