source: frontend/node_modules/webpack/lib/dependencies/CachedConstDependency.js

/*
        MIT License http://www.opensource.org/licenses/mit-license.php
        Author Florent Cailhol @ooflorent
*/

"use strict";

const DependencyTemplate = require("../DependencyTemplate");
const InitFragment = require("../InitFragment");
const makeSerializable = require("../util/makeSerializable");
const NullDependency = require("./NullDependency");

/** @typedef {import("webpack-sources").ReplaceSource} ReplaceSource */
/** @typedef {import("../Dependency")} Dependency */
/** @typedef {import("../Dependency").UpdateHashContext} UpdateHashContext */
/** @typedef {import("../DependencyTemplate").DependencyTemplateContext} DependencyTemplateContext */
/** @typedef {import("../javascript/JavascriptParser").Range} Range */
/** @typedef {import("../serialization/ObjectMiddleware").ObjectDeserializerContext} ObjectDeserializerContext */
/** @typedef {import("../serialization/ObjectMiddleware").ObjectSerializerContext} ObjectSerializerContext */
/** @typedef {import("../util/Hash")} Hash */

class CachedConstDependency extends NullDependency {
        /**
         * Creates an instance of CachedConstDependency.
         * @param {string} expression expression
         * @param {Range | null} range range
         * @param {string} identifier identifier
         * @param {number=} place place where we inject the expression
         */
        constructor(
                expression,
                range,
                identifier,
                place = CachedConstDependency.PLACE_MODULE
        ) {
                super();

                this.expression = expression;
                this.range = range;
                this.identifier = identifier;
                this.place = place;
                /** @type {undefined | string} */
                this._hashUpdate = undefined;
        }

        /**
         * Create hash update.
         * @returns {string} hash update
         */
        _createHashUpdate() {
                return `${this.place}${this.identifier}${this.range}${this.expression}`;
        }

        /**
         * Updates the hash with the data contributed by this instance.
         * @param {Hash} hash hash to be updated
         * @param {UpdateHashContext} context context
         * @returns {void}
         */
        updateHash(hash, context) {
                if (this._hashUpdate === undefined) {
                        this._hashUpdate = this._createHashUpdate();
                }
                hash.update(this._hashUpdate);
        }

        /**
         * Serializes this instance into the provided serializer context.
         * @param {ObjectSerializerContext} context context
         */
        serialize(context) {
                const { write } = context;

                write(this.expression);
                write(this.range);
                write(this.identifier);
                write(this.place);

                super.serialize(context);
        }

        /**
         * Restores this instance from the provided deserializer context.
         * @param {ObjectDeserializerContext} context context
         */
        deserialize(context) {
                const { read } = context;

                this.expression = read();
                this.range = read();
                this.identifier = read();
                this.place = read();

                super.deserialize(context);
        }
}

CachedConstDependency.PLACE_MODULE = 10;
CachedConstDependency.PLACE_CHUNK = 20;

makeSerializable(
        CachedConstDependency,
        "webpack/lib/dependencies/CachedConstDependency"
);

CachedConstDependency.Template = class CachedConstDependencyTemplate extends (
        DependencyTemplate
) {
        /**
         * Applies the plugin by registering its hooks on the compiler.
         * @param {Dependency} dependency the dependency for which the template should be applied
         * @param {ReplaceSource} source the current replace source which can be modified
         * @param {DependencyTemplateContext} templateContext the context object
         * @returns {void}
         */
        apply(dependency, source, { initFragments, chunkInitFragments }) {
                const dep = /** @type {CachedConstDependency} */ (dependency);

                (dep.place === CachedConstDependency.PLACE_MODULE
                        ? initFragments
                        : chunkInitFragments
                ).push(
                        new InitFragment(
                                `var ${dep.identifier} = ${dep.expression};\n`,
                                InitFragment.STAGE_CONSTANTS,
                                // For a chunk we inject expression after imports
                                dep.place === CachedConstDependency.PLACE_MODULE ? 0 : 10,
                                `const ${dep.identifier}`
                        )
                );

                if (typeof dep.range === "number") {
                        source.insert(dep.range, dep.identifier);
                } else if (dep.range !== null) {
                        source.replace(dep.range[0], dep.range[1] - 1, dep.identifier);
                }
        }
};

module.exports = CachedConstDependency;