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/* | ||
MIT License http://www.opensource.org/licenses/mit-license.php | ||
Author Tobias Koppers @sokra | ||
*/ | ||
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"use strict"; | ||
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/** @typedef {import("../Dependency")} Dependency */ | ||
/** @typedef {import("../ModuleGraph")} ModuleGraph */ | ||
/** @typedef {import("../javascript/JavascriptParser").Range} Range */ | ||
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/** | ||
* @summary Get the subset of ids and their corresponding range in an id chain that should be re-rendered by webpack. | ||
* Only those in the chain that are actually referring to namespaces or imports should be re-rendered. | ||
* Deeper member accessors on the imported object should not be re-rendered. If deeper member accessors are re-rendered, | ||
* there is a potential loss of meaning with rendering a quoted accessor as an unquoted accessor, or vice versa, | ||
* because minifiers treat quoted accessors differently. e.g. import { a } from "./module"; a["b"] vs a.b | ||
* @param {string[]} untrimmedIds chained ids | ||
* @param {Range} untrimmedRange range encompassing allIds | ||
* @param {Range[]} ranges cumulative range of ids for each of allIds | ||
* @param {ModuleGraph} moduleGraph moduleGraph | ||
* @param {Dependency} dependency dependency | ||
* @returns {{trimmedIds: string[], trimmedRange: Range}} computed trimmed ids and cumulative range of those ids | ||
*/ | ||
exports.getTrimmedIdsAndRange = ( | ||
untrimmedIds, | ||
untrimmedRange, | ||
ranges, | ||
moduleGraph, | ||
dependency | ||
) => { | ||
let trimmedIds = trimIdsToThoseImported( | ||
untrimmedIds, | ||
moduleGraph, | ||
dependency | ||
); | ||
let trimmedRange = untrimmedRange; | ||
if (trimmedIds.length !== untrimmedIds.length) { | ||
// The array returned from dep.idRanges is right-aligned with the array returned from dep.names. | ||
// Meaning, the two arrays may not always have the same number of elements, but the last element of | ||
// dep.idRanges corresponds to [the expression fragment to the left of] the last element of dep.names. | ||
// Use this to find the correct replacement range based on the number of ids that were trimmed. | ||
const idx = | ||
ranges === undefined | ||
? -1 /* trigger failure case below */ | ||
: ranges.length + (trimmedIds.length - untrimmedIds.length); | ||
if (idx < 0 || idx >= ranges.length) { | ||
// cspell:ignore minifiers | ||
// Should not happen but we can't throw an error here because of backward compatibility with | ||
// external plugins in wp5. Instead, we just disable trimming for now. This may break some minifiers. | ||
trimmedIds = untrimmedIds; | ||
// TODO webpack 6 remove the "trimmedIds = ids" above and uncomment the following line instead. | ||
// throw new Error("Missing range starts data for id replacement trimming."); | ||
} else { | ||
trimmedRange = ranges[idx]; | ||
} | ||
} | ||
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return { trimmedIds, trimmedRange }; | ||
}; | ||
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/** | ||
* @summary Determine which IDs in the id chain are actually referring to namespaces or imports, | ||
* and which are deeper member accessors on the imported object. | ||
* @param {string[]} ids untrimmed ids | ||
* @param {ModuleGraph} moduleGraph moduleGraph | ||
* @param {Dependency} dependency dependency | ||
* @returns {string[]} trimmed ids | ||
*/ | ||
function trimIdsToThoseImported(ids, moduleGraph, dependency) { | ||
let trimmedIds = []; | ||
const exportsInfo = moduleGraph.getExportsInfo( | ||
moduleGraph.getModule(dependency) | ||
); | ||
let currentExportsInfo = /** @type {ExportsInfo=} */ exportsInfo; | ||
for (let i = 0; i < ids.length; i++) { | ||
if (i === 0 && ids[i] === "default") { | ||
continue; // ExportInfo for the next level under default is still at the root ExportsInfo, so don't advance currentExportsInfo | ||
} | ||
const exportInfo = currentExportsInfo.getExportInfo(ids[i]); | ||
if (exportInfo.provided === false) { | ||
// json imports have nested ExportInfo for elements that things that are not actually exported, so check .provided | ||
trimmedIds = ids.slice(0, i); | ||
break; | ||
} | ||
const nestedInfo = exportInfo.getNestedExportsInfo(); | ||
if (!nestedInfo) { | ||
// once all nested exports are traversed, the next item is the actual import so stop there | ||
trimmedIds = ids.slice(0, i + 1); | ||
break; | ||
} | ||
currentExportsInfo = nestedInfo; | ||
} | ||
// Never trim to nothing. This can happen for invalid imports (e.g. import { notThere } from "./module", or import { anything } from "./missingModule") | ||
return trimmedIds.length ? trimmedIds : ids; | ||
} |