mirror of https://github.com/webpack/webpack.git
				
				
				
			
		
			
				
	
	
		
			404 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
			
		
		
	
	
			404 lines
		
	
	
		
			13 KiB
		
	
	
	
		
			JavaScript
		
	
	
	
| /*
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| 	MIT License http://www.opensource.org/licenses/mit-license.php
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| 	Author Tobias Koppers @sokra
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| */
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| 
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| "use strict";
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| 
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| const {
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| 	JAVASCRIPT_MODULE_TYPE_AUTO,
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| 	JAVASCRIPT_MODULE_TYPE_ESM
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| } = require("../ModuleTypeConstants");
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| const PureExpressionDependency = require("../dependencies/PureExpressionDependency");
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| const InnerGraph = require("./InnerGraph");
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| 
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| /** @typedef {import("estree").ClassDeclaration} ClassDeclarationNode */
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| /** @typedef {import("estree").ClassExpression} ClassExpressionNode */
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| /** @typedef {import("estree").Node} Node */
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| /** @typedef {import("estree").VariableDeclarator} VariableDeclaratorNode */
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| /** @typedef {import("../../declarations/WebpackOptions").JavascriptParserOptions} JavascriptParserOptions */
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| /** @typedef {import("../Compiler")} Compiler */
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| /** @typedef {import("../Dependency")} Dependency */
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| /** @typedef {import("../dependencies/HarmonyImportSpecifierDependency")} HarmonyImportSpecifierDependency */
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| /** @typedef {import("../javascript/JavascriptParser")} JavascriptParser */
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| /** @typedef {import("../javascript/JavascriptParser").Range} Range */
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| /** @typedef {import("./InnerGraph").InnerGraph} InnerGraph */
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| /** @typedef {import("./InnerGraph").TopLevelSymbol} TopLevelSymbol */
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| 
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| const { topLevelSymbolTag } = InnerGraph;
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| 
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| const PLUGIN_NAME = "InnerGraphPlugin";
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| 
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| class InnerGraphPlugin {
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| 	/**
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| 	 * Apply the plugin
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| 	 * @param {Compiler} compiler the compiler instance
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| 	 * @returns {void}
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| 	 */
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| 	apply(compiler) {
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| 		compiler.hooks.compilation.tap(
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| 			PLUGIN_NAME,
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| 			(compilation, { normalModuleFactory }) => {
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| 				const logger = compilation.getLogger("webpack.InnerGraphPlugin");
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| 
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| 				compilation.dependencyTemplates.set(
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| 					PureExpressionDependency,
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| 					new PureExpressionDependency.Template()
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| 				);
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| 
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| 				/**
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| 				 * @param {JavascriptParser} parser the parser
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| 				 * @param {JavascriptParserOptions} parserOptions options
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| 				 * @returns {void}
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| 				 */
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| 				const handler = (parser, parserOptions) => {
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| 					const onUsageSuper = sup => {
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| 						InnerGraph.onUsage(parser.state, usedByExports => {
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| 							switch (usedByExports) {
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| 								case undefined:
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| 								case true:
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| 									return;
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| 								default: {
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| 									const dep = new PureExpressionDependency(sup.range);
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| 									dep.loc = sup.loc;
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| 									dep.usedByExports = usedByExports;
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| 									parser.state.module.addDependency(dep);
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| 									break;
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| 								}
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| 							}
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| 						});
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| 					};
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| 
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| 					parser.hooks.program.tap(PLUGIN_NAME, () => {
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| 						InnerGraph.enable(parser.state);
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| 					});
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| 
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| 					parser.hooks.finish.tap(PLUGIN_NAME, () => {
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| 						if (!InnerGraph.isEnabled(parser.state)) return;
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| 
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| 						logger.time("infer dependency usage");
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| 						InnerGraph.inferDependencyUsage(parser.state);
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| 						logger.timeAggregate("infer dependency usage");
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| 					});
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| 
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| 					// During prewalking the following datastructures are filled with
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| 					// nodes that have a TopLevelSymbol assigned and
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| 					// variables are tagged with the assigned TopLevelSymbol
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| 
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| 					// We differ 3 types of nodes:
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| 					// 1. full statements (export default, function declaration)
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| 					// 2. classes (class declaration, class expression)
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| 					// 3. variable declarators (const x = ...)
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| 
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| 					/** @type {WeakMap<Node, TopLevelSymbol>} */
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| 					const statementWithTopLevelSymbol = new WeakMap();
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| 					/** @type {WeakMap<Node, Node>} */
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| 					const statementPurePart = new WeakMap();
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| 
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| 					/** @type {WeakMap<ClassExpressionNode | ClassDeclarationNode, TopLevelSymbol>} */
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| 					const classWithTopLevelSymbol = new WeakMap();
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| 
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| 					/** @type {WeakMap<VariableDeclaratorNode, TopLevelSymbol>} */
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| 					const declWithTopLevelSymbol = new WeakMap();
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| 					/** @type {WeakSet<VariableDeclaratorNode>} */
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| 					const pureDeclarators = new WeakSet();
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| 
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| 					// The following hooks are used during prewalking:
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| 
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| 					parser.hooks.preStatement.tap(PLUGIN_NAME, statement => {
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| 						if (!InnerGraph.isEnabled(parser.state)) return;
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| 
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| 						if (parser.scope.topLevelScope === true) {
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| 							if (statement.type === "FunctionDeclaration") {
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| 								const name = statement.id ? statement.id.name : "*default*";
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| 								const fn = InnerGraph.tagTopLevelSymbol(parser, name);
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| 								statementWithTopLevelSymbol.set(statement, fn);
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| 								return true;
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| 							}
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| 						}
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| 					});
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| 
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| 					parser.hooks.blockPreStatement.tap(PLUGIN_NAME, statement => {
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| 						if (!InnerGraph.isEnabled(parser.state)) return;
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| 
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| 						if (parser.scope.topLevelScope === true) {
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| 							if (
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| 								statement.type === "ClassDeclaration" &&
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| 								parser.isPure(
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| 									statement,
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| 									/** @type {Range} */ (statement.range)[0]
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| 								)
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| 							) {
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| 								const name = statement.id ? statement.id.name : "*default*";
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| 								const fn = InnerGraph.tagTopLevelSymbol(parser, name);
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| 								classWithTopLevelSymbol.set(statement, fn);
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| 								return true;
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| 							}
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| 							if (statement.type === "ExportDefaultDeclaration") {
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| 								const name = "*default*";
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| 								const fn = InnerGraph.tagTopLevelSymbol(parser, name);
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| 								const decl = statement.declaration;
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| 								if (
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| 									(decl.type === "ClassExpression" ||
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| 										decl.type === "ClassDeclaration") &&
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| 									parser.isPure(decl, /** @type {Range} */ (decl.range)[0])
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| 								) {
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| 									classWithTopLevelSymbol.set(decl, fn);
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| 								} else if (
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| 									parser.isPure(decl, /** @type {Range} */ (statement.range)[0])
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| 								) {
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| 									statementWithTopLevelSymbol.set(statement, fn);
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| 									if (
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| 										!decl.type.endsWith("FunctionExpression") &&
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| 										!decl.type.endsWith("Declaration") &&
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| 										decl.type !== "Literal"
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| 									) {
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| 										statementPurePart.set(statement, decl);
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| 									}
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| 								}
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| 							}
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| 						}
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| 					});
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| 
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| 					parser.hooks.preDeclarator.tap(PLUGIN_NAME, (decl, statement) => {
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| 						if (!InnerGraph.isEnabled(parser.state)) return;
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| 						if (
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| 							parser.scope.topLevelScope === true &&
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| 							decl.init &&
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| 							decl.id.type === "Identifier"
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| 						) {
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| 							const name = decl.id.name;
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| 							if (
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| 								decl.init.type === "ClassExpression" &&
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| 								parser.isPure(
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| 									decl.init,
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| 									/** @type {Range} */ (decl.id.range)[1]
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| 								)
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| 							) {
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| 								const fn = InnerGraph.tagTopLevelSymbol(parser, name);
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| 								classWithTopLevelSymbol.set(decl.init, fn);
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| 							} else if (
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| 								parser.isPure(
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| 									decl.init,
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| 									/** @type {Range} */ (decl.id.range)[1]
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| 								)
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| 							) {
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| 								const fn = InnerGraph.tagTopLevelSymbol(parser, name);
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| 								declWithTopLevelSymbol.set(decl, fn);
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| 								if (
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| 									!decl.init.type.endsWith("FunctionExpression") &&
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| 									decl.init.type !== "Literal"
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| 								) {
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| 									pureDeclarators.add(decl);
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| 								}
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| 							}
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| 						}
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| 					});
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| 
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| 					// During real walking we set the TopLevelSymbol state to the assigned
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| 					// TopLevelSymbol by using the fill datastructures.
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| 
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| 					// In addition to tracking TopLevelSymbols, we sometimes need to
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| 					// add a PureExpressionDependency. This is needed to skip execution
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| 					// of pure expressions, even when they are not dropped due to
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| 					// minimizing. Otherwise symbols used there might not exist anymore
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| 					// as they are removed as unused by this optimization
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| 
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| 					// When we find a reference to a TopLevelSymbol, we register a
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| 					// TopLevelSymbol dependency from TopLevelSymbol in state to the
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| 					// referenced TopLevelSymbol. This way we get a graph of all
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| 					// TopLevelSymbols.
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| 
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| 					// The following hooks are called during walking:
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| 
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| 					parser.hooks.statement.tap(PLUGIN_NAME, statement => {
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| 						if (!InnerGraph.isEnabled(parser.state)) return;
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| 						if (parser.scope.topLevelScope === true) {
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| 							InnerGraph.setTopLevelSymbol(parser.state, undefined);
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| 
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| 							const fn = statementWithTopLevelSymbol.get(statement);
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| 							if (fn) {
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| 								InnerGraph.setTopLevelSymbol(parser.state, fn);
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| 								const purePart = statementPurePart.get(statement);
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| 								if (purePart) {
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| 									InnerGraph.onUsage(parser.state, usedByExports => {
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| 										switch (usedByExports) {
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| 											case undefined:
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| 											case true:
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| 												return;
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| 											default: {
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| 												const dep = new PureExpressionDependency(
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| 													/** @type {Range} */ (purePart.range)
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| 												);
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| 												dep.loc = statement.loc;
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| 												dep.usedByExports = usedByExports;
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| 												parser.state.module.addDependency(dep);
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| 												break;
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| 											}
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| 										}
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| 									});
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| 								}
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| 							}
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| 						}
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| 					});
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| 
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| 					parser.hooks.classExtendsExpression.tap(
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| 						PLUGIN_NAME,
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| 						(expr, statement) => {
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| 							if (!InnerGraph.isEnabled(parser.state)) return;
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| 							if (parser.scope.topLevelScope === true) {
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| 								const fn = classWithTopLevelSymbol.get(statement);
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| 								if (
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| 									fn &&
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| 									parser.isPure(
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| 										expr,
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| 										statement.id
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| 											? /** @type {Range} */ (statement.id.range)[1]
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| 											: /** @type {Range} */ (statement.range)[0]
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| 									)
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| 								) {
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| 									InnerGraph.setTopLevelSymbol(parser.state, fn);
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| 									onUsageSuper(expr);
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| 								}
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| 							}
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| 						}
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| 					);
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| 
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| 					parser.hooks.classBodyElement.tap(
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| 						PLUGIN_NAME,
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| 						(element, classDefinition) => {
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| 							if (!InnerGraph.isEnabled(parser.state)) return;
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| 							if (parser.scope.topLevelScope === true) {
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| 								const fn = classWithTopLevelSymbol.get(classDefinition);
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| 								if (fn) {
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| 									InnerGraph.setTopLevelSymbol(parser.state, undefined);
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| 								}
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| 							}
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| 						}
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| 					);
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| 
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| 					parser.hooks.classBodyValue.tap(
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| 						PLUGIN_NAME,
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| 						(expression, element, classDefinition) => {
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| 							if (!InnerGraph.isEnabled(parser.state)) return;
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| 							if (parser.scope.topLevelScope === true) {
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| 								const fn = classWithTopLevelSymbol.get(classDefinition);
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| 								if (fn) {
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| 									if (
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| 										!element.static ||
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| 										parser.isPure(
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| 											expression,
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| 											element.key
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| 												? /** @type {Range} */ (element.key.range)[1]
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| 												: /** @type {Range} */ (element.range)[0]
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| 										)
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| 									) {
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| 										InnerGraph.setTopLevelSymbol(parser.state, fn);
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| 										if (element.type !== "MethodDefinition" && element.static) {
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| 											InnerGraph.onUsage(parser.state, usedByExports => {
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| 												switch (usedByExports) {
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| 													case undefined:
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| 													case true:
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| 														return;
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| 													default: {
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| 														const dep = new PureExpressionDependency(
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| 															/** @type {Range} */ (expression.range)
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| 														);
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| 														dep.loc = expression.loc;
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| 														dep.usedByExports = usedByExports;
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| 														parser.state.module.addDependency(dep);
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| 														break;
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| 													}
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| 												}
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| 											});
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| 										}
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| 									} else {
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| 										InnerGraph.setTopLevelSymbol(parser.state, undefined);
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| 									}
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| 								}
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| 							}
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| 						}
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| 					);
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| 
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| 					parser.hooks.declarator.tap(PLUGIN_NAME, (decl, statement) => {
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| 						if (!InnerGraph.isEnabled(parser.state)) return;
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| 						const fn = declWithTopLevelSymbol.get(decl);
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| 
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| 						if (fn) {
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| 							InnerGraph.setTopLevelSymbol(parser.state, fn);
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| 							if (pureDeclarators.has(decl)) {
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| 								if (decl.init.type === "ClassExpression") {
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| 									if (decl.init.superClass) {
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| 										onUsageSuper(decl.init.superClass);
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| 									}
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| 								} else {
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| 									InnerGraph.onUsage(parser.state, usedByExports => {
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| 										switch (usedByExports) {
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| 											case undefined:
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| 											case true:
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| 												return;
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| 											default: {
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| 												const dep = new PureExpressionDependency(
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| 													/** @type {Range} */ (decl.init.range)
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| 												);
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| 												dep.loc = decl.loc;
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| 												dep.usedByExports = usedByExports;
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| 												parser.state.module.addDependency(dep);
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| 												break;
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| 											}
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| 										}
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| 									});
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| 								}
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| 							}
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| 							parser.walkExpression(decl.init);
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| 							InnerGraph.setTopLevelSymbol(parser.state, undefined);
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| 							return true;
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| 						} else if (
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| 							decl.id.type === "Identifier" &&
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| 							decl.init &&
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| 							decl.init.type === "ClassExpression" &&
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| 							classWithTopLevelSymbol.has(decl.init)
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| 						) {
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| 							parser.walkExpression(decl.init);
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| 							InnerGraph.setTopLevelSymbol(parser.state, undefined);
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| 							return true;
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| 						}
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| 					});
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| 
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| 					parser.hooks.expression
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| 						.for(topLevelSymbolTag)
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| 						.tap(PLUGIN_NAME, () => {
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| 							const topLevelSymbol = /** @type {TopLevelSymbol} */ (
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| 								parser.currentTagData
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| 							);
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| 							const currentTopLevelSymbol = InnerGraph.getTopLevelSymbol(
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| 								parser.state
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| 							);
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| 							InnerGraph.addUsage(
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| 								parser.state,
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| 								topLevelSymbol,
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| 								currentTopLevelSymbol || true
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| 							);
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| 						});
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| 					parser.hooks.assign.for(topLevelSymbolTag).tap(PLUGIN_NAME, expr => {
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| 						if (!InnerGraph.isEnabled(parser.state)) return;
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| 						if (expr.operator === "=") return true;
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| 					});
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| 				};
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| 				normalModuleFactory.hooks.parser
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| 					.for(JAVASCRIPT_MODULE_TYPE_AUTO)
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| 					.tap(PLUGIN_NAME, handler);
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| 				normalModuleFactory.hooks.parser
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| 					.for(JAVASCRIPT_MODULE_TYPE_ESM)
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| 					.tap(PLUGIN_NAME, handler);
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| 
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| 				compilation.hooks.finishModules.tap(PLUGIN_NAME, () => {
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| 					logger.timeAggregateEnd("infer dependency usage");
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| 				});
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| 			}
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| 		);
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| 	}
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| }
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| 
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| module.exports = InnerGraphPlugin;
 |