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- /*
- MIT License http://www.opensource.org/licenses/mit-license.php
- Author Tobias Koppers @sokra
- */
- "use strict";
-
- const mm = require("micromatch");
- const HarmonyExportImportedSpecifierDependency = require("../dependencies/HarmonyExportImportedSpecifierDependency");
- const HarmonyImportSideEffectDependency = require("../dependencies/HarmonyImportSideEffectDependency");
- const HarmonyImportSpecifierDependency = require("../dependencies/HarmonyImportSpecifierDependency");
-
- /** @typedef {import("../Module")} Module */
- /** @typedef {import("../Dependency")} Dependency */
-
- /**
- * @typedef {Object} ExportInModule
- * @property {Module} module the module
- * @property {string} exportName the name of the export
- */
-
- class SideEffectsFlagPlugin {
- apply(compiler) {
- compiler.hooks.normalModuleFactory.tap("SideEffectsFlagPlugin", nmf => {
- nmf.hooks.module.tap("SideEffectsFlagPlugin", (module, data) => {
- const resolveData = data.resourceResolveData;
- if (
- resolveData &&
- resolveData.descriptionFileData &&
- resolveData.relativePath
- ) {
- const sideEffects = resolveData.descriptionFileData.sideEffects;
- const hasSideEffects = SideEffectsFlagPlugin.moduleHasSideEffects(
- resolveData.relativePath,
- sideEffects
- );
- if (!hasSideEffects) {
- module.factoryMeta.sideEffectFree = true;
- }
- }
-
- return module;
- });
- nmf.hooks.module.tap("SideEffectsFlagPlugin", (module, data) => {
- if (data.settings.sideEffects === false) {
- module.factoryMeta.sideEffectFree = true;
- } else if (data.settings.sideEffects === true) {
- module.factoryMeta.sideEffectFree = false;
- }
- });
- });
- compiler.hooks.compilation.tap("SideEffectsFlagPlugin", compilation => {
- compilation.hooks.optimizeDependencies.tap(
- "SideEffectsFlagPlugin",
- modules => {
- /** @type {Map<Module, Map<string, ExportInModule>>} */
- const reexportMaps = new Map();
-
- // Capture reexports of sideEffectFree modules
- for (const module of modules) {
- /** @type {Dependency[]} */
- const removeDependencies = [];
- for (const dep of module.dependencies) {
- if (dep instanceof HarmonyImportSideEffectDependency) {
- if (dep.module && dep.module.factoryMeta.sideEffectFree) {
- removeDependencies.push(dep);
- }
- } else if (
- dep instanceof HarmonyExportImportedSpecifierDependency
- ) {
- if (module.factoryMeta.sideEffectFree) {
- const mode = dep.getMode(true);
- if (mode.type === "safe-reexport") {
- let map = reexportMaps.get(module);
- if (!map) {
- reexportMaps.set(module, (map = new Map()));
- }
- for (const pair of mode.map) {
- map.set(pair[0], {
- module: mode.module,
- exportName: pair[1]
- });
- }
- }
- }
- }
- }
- }
-
- // Flatten reexports
- for (const map of reexportMaps.values()) {
- for (const pair of map) {
- let mapping = pair[1];
- while (mapping) {
- const innerMap = reexportMaps.get(mapping.module);
- if (!innerMap) break;
- const newMapping = innerMap.get(mapping.exportName);
- if (newMapping) {
- map.set(pair[0], newMapping);
- }
- mapping = newMapping;
- }
- }
- }
-
- // Update imports along the reexports from sideEffectFree modules
- for (const pair of reexportMaps) {
- const module = pair[0];
- const map = pair[1];
- let newReasons = undefined;
- for (let i = 0; i < module.reasons.length; i++) {
- const reason = module.reasons[i];
- const dep = reason.dependency;
- if (
- dep instanceof HarmonyExportImportedSpecifierDependency ||
- (dep instanceof HarmonyImportSpecifierDependency &&
- !dep.namespaceObjectAsContext)
- ) {
- const mapping = map.get(dep.id);
- if (mapping) {
- dep.redirectedModule = mapping.module;
- dep.redirectedId = mapping.exportName;
- mapping.module.addReason(
- reason.module,
- dep,
- reason.explanation
- ? reason.explanation +
- " (skipped side-effect-free modules)"
- : "(skipped side-effect-free modules)"
- );
- // removing the currect reason, by not adding it to the newReasons array
- // lazily create the newReasons array
- if (newReasons === undefined) {
- newReasons = i === 0 ? [] : module.reasons.slice(0, i);
- }
- continue;
- }
- }
- if (newReasons !== undefined) newReasons.push(reason);
- }
- if (newReasons !== undefined) {
- module.reasons = newReasons;
- }
- }
- }
- );
- });
- }
-
- static moduleHasSideEffects(moduleName, flagValue) {
- switch (typeof flagValue) {
- case "undefined":
- return true;
- case "boolean":
- return flagValue;
- case "string":
- if (process.platform === "win32") {
- flagValue = flagValue.replace(/\\/g, "/");
- }
- return mm.isMatch(moduleName, flagValue, {
- matchBase: true
- });
- case "object":
- return flagValue.some(glob =>
- SideEffectsFlagPlugin.moduleHasSideEffects(moduleName, glob)
- );
- }
- }
- }
- module.exports = SideEffectsFlagPlugin;
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