Method handler

lib/UseStrictPlugin.js:39–66

(parser, parserOptions)

				 * @param {JavascriptParserOptions} parserOptions the javascript parser options
				 */
				const handler = (parser, parserOptions) => {
					parser.hooks.program.tap(PLUGIN_NAME, (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(
								"",
								/** @type {Range} */ (firstNode.range)
							);
							dep.loc = /** @type {DependencyLocation} */ (firstNode.loc);
							parser.state.module.addPresentationalDependency(dep);
							/** @type {BuildInfo} */
							(parser.state.module.buildInfo).strict = true;
						}
						if (parserOptions.overrideStrict) {
							/** @type {BuildInfo} */
							(parser.state.module.buildInfo).strict =
								parserOptions.overrideStrict === "strict";
						}
					});
				};

				normalModuleFactory.hooks.parser
					.for(JAVASCRIPT_MODULE_TYPE_AUTO)