webpack/lib/UseStrictPlugin.js

40 lines
1.4 KiB
JavaScript

/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Tobias Koppers @sokra
*/
"use strict";
const ConstDependency = require("./dependencies/ConstDependency");
class UseStrictPlugin {
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.current.addDependency(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;