securityos/node_modules/enhanced-resolve/lib/util/entrypoints.js

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2024-09-06 15:32:35 +00:00
/*
MIT License http://www.opensource.org/licenses/mit-license.php
Author Ivan Kopeykin @vankop
*/
"use strict";
/** @typedef {string|(string|ConditionalMapping)[]} DirectMapping */
/** @typedef {{[k: string]: MappingValue}} ConditionalMapping */
/** @typedef {ConditionalMapping|DirectMapping|null} MappingValue */
/** @typedef {Record<string, MappingValue>|ConditionalMapping|DirectMapping} ExportsField */
/** @typedef {Record<string, MappingValue>} ImportsField */
/**
* @typedef {Object} PathTreeNode
* @property {Map<string, PathTreeNode>|null} children
* @property {MappingValue} folder
* @property {Map<string, MappingValue>|null} wildcards
* @property {Map<string, MappingValue>} files
*/
/**
* Processing exports/imports field
* @callback FieldProcessor
* @param {string} request request
* @param {Set<string>} conditionNames condition names
* @returns {string[]} resolved paths
*/
/*
Example exports field:
{
".": "./main.js",
"./feature": {
"browser": "./feature-browser.js",
"default": "./feature.js"
}
}
Terminology:
Enhanced-resolve name keys ("." and "./feature") as exports field keys.
If value is string or string[], mapping is called as a direct mapping
and value called as a direct export.
If value is key-value object, mapping is called as a conditional mapping
and value called as a conditional export.
Key in conditional mapping is called condition name.
Conditional mapping nested in another conditional mapping is called nested mapping.
----------
Example imports field:
{
"#a": "./main.js",
"#moment": {
"browser": "./moment/index.js",
"default": "moment"
},
"#moment/": {
"browser": "./moment/",
"default": "moment/"
}
}
Terminology:
Enhanced-resolve name keys ("#a" and "#moment/", "#moment") as imports field keys.
If value is string or string[], mapping is called as a direct mapping
and value called as a direct export.
If value is key-value object, mapping is called as a conditional mapping
and value called as a conditional export.
Key in conditional mapping is called condition name.
Conditional mapping nested in another conditional mapping is called nested mapping.
*/
const slashCode = "/".charCodeAt(0);
const dotCode = ".".charCodeAt(0);
const hashCode = "#".charCodeAt(0);
/**
* @param {ExportsField} exportsField the exports field
* @returns {FieldProcessor} process callback
*/
module.exports.processExportsField = function processExportsField(
exportsField
) {
return createFieldProcessor(
buildExportsFieldPathTree(exportsField),
assertExportsFieldRequest,
assertExportTarget
);
};
/**
* @param {ImportsField} importsField the exports field
* @returns {FieldProcessor} process callback
*/
module.exports.processImportsField = function processImportsField(
importsField
) {
return createFieldProcessor(
buildImportsFieldPathTree(importsField),
assertImportsFieldRequest,
assertImportTarget
);
};
/**
* @param {PathTreeNode} treeRoot root
* @param {(s: string) => string} assertRequest assertRequest
* @param {(s: string, f: boolean) => void} assertTarget assertTarget
* @returns {FieldProcessor} field processor
*/
function createFieldProcessor(treeRoot, assertRequest, assertTarget) {
return function fieldProcessor(request, conditionNames) {
request = assertRequest(request);
const match = findMatch(request, treeRoot);
if (match === null) return [];
const [mapping, remainRequestIndex] = match;
/** @type {DirectMapping|null} */
let direct = null;
if (isConditionalMapping(mapping)) {
direct = conditionalMapping(
/** @type {ConditionalMapping} */ (mapping),
conditionNames
);
// matching not found
if (direct === null) return [];
} else {
direct = /** @type {DirectMapping} */ (mapping);
}
const remainingRequest =
remainRequestIndex === request.length + 1
? undefined
: remainRequestIndex < 0
? request.slice(-remainRequestIndex - 1)
: request.slice(remainRequestIndex);
return directMapping(
remainingRequest,
remainRequestIndex < 0,
direct,
conditionNames,
assertTarget
);
};
}
/**
* @param {string} request request
* @returns {string} updated request
*/
function assertExportsFieldRequest(request) {
if (request.charCodeAt(0) !== dotCode) {
throw new Error('Request should be relative path and start with "."');
}
if (request.length === 1) return "";
if (request.charCodeAt(1) !== slashCode) {
throw new Error('Request should be relative path and start with "./"');
}
if (request.charCodeAt(request.length - 1) === slashCode) {
throw new Error("Only requesting file allowed");
}
return request.slice(2);
}
/**
* @param {string} request request
* @returns {string} updated request
*/
function assertImportsFieldRequest(request) {
if (request.charCodeAt(0) !== hashCode) {
throw new Error('Request should start with "#"');
}
if (request.length === 1) {
throw new Error("Request should have at least 2 characters");
}
if (request.charCodeAt(1) === slashCode) {
throw new Error('Request should not start with "#/"');
}
if (request.charCodeAt(request.length - 1) === slashCode) {
throw new Error("Only requesting file allowed");
}
return request.slice(1);
}
/**
* @param {string} exp export target
* @param {boolean} expectFolder is folder expected
*/
function assertExportTarget(exp, expectFolder) {
if (
exp.charCodeAt(0) === slashCode ||
(exp.charCodeAt(0) === dotCode && exp.charCodeAt(1) !== slashCode)
) {
throw new Error(
`Export should be relative path and start with "./", got ${JSON.stringify(
exp
)}.`
);
}
const isFolder = exp.charCodeAt(exp.length - 1) === slashCode;
if (isFolder !== expectFolder) {
throw new Error(
expectFolder
? `Expecting folder to folder mapping. ${JSON.stringify(
exp
)} should end with "/"`
: `Expecting file to file mapping. ${JSON.stringify(
exp
)} should not end with "/"`
);
}
}
/**
* @param {string} imp import target
* @param {boolean} expectFolder is folder expected
*/
function assertImportTarget(imp, expectFolder) {
const isFolder = imp.charCodeAt(imp.length - 1) === slashCode;
if (isFolder !== expectFolder) {
throw new Error(
expectFolder
? `Expecting folder to folder mapping. ${JSON.stringify(
imp
)} should end with "/"`
: `Expecting file to file mapping. ${JSON.stringify(
imp
)} should not end with "/"`
);
}
}
/**
* Trying to match request to field
* @param {string} request request
* @param {PathTreeNode} treeRoot path tree root
* @returns {[MappingValue, number]|null} match or null, number is negative and one less when it's a folder mapping, number is request.length + 1 for direct mappings
*/
function findMatch(request, treeRoot) {
if (request.length === 0) {
const value = treeRoot.files.get("");
return value ? [value, 1] : null;
}
if (
treeRoot.children === null &&
treeRoot.folder === null &&
treeRoot.wildcards === null
) {
const value = treeRoot.files.get(request);
return value ? [value, request.length + 1] : null;
}
let node = treeRoot;
let lastNonSlashIndex = 0;
let slashIndex = request.indexOf("/", 0);
/** @type {[MappingValue, number]|null} */
let lastFolderMatch = null;
const applyFolderMapping = () => {
const folderMapping = node.folder;
if (folderMapping) {
if (lastFolderMatch) {
lastFolderMatch[0] = folderMapping;
lastFolderMatch[1] = -lastNonSlashIndex - 1;
} else {
lastFolderMatch = [folderMapping, -lastNonSlashIndex - 1];
}
}
};
const applyWildcardMappings = (wildcardMappings, remainingRequest) => {
if (wildcardMappings) {
for (const [key, target] of wildcardMappings) {
if (remainingRequest.startsWith(key)) {
if (!lastFolderMatch) {
lastFolderMatch = [target, lastNonSlashIndex + key.length];
} else if (lastFolderMatch[1] < lastNonSlashIndex + key.length) {
lastFolderMatch[0] = target;
lastFolderMatch[1] = lastNonSlashIndex + key.length;
}
}
}
}
};
while (slashIndex !== -1) {
applyFolderMapping();
const wildcardMappings = node.wildcards;
if (!wildcardMappings && node.children === null) return lastFolderMatch;
const folder = request.slice(lastNonSlashIndex, slashIndex);
applyWildcardMappings(wildcardMappings, folder);
if (node.children === null) return lastFolderMatch;
const newNode = node.children.get(folder);
if (!newNode) {
return lastFolderMatch;
}
node = newNode;
lastNonSlashIndex = slashIndex + 1;
slashIndex = request.indexOf("/", lastNonSlashIndex);
}
const remainingRequest =
lastNonSlashIndex > 0 ? request.slice(lastNonSlashIndex) : request;
const value = node.files.get(remainingRequest);
if (value) {
return [value, request.length + 1];
}
applyFolderMapping();
applyWildcardMappings(node.wildcards, remainingRequest);
return lastFolderMatch;
}
/**
* @param {ConditionalMapping|DirectMapping|null} mapping mapping
* @returns {boolean} is conditional mapping
*/
function isConditionalMapping(mapping) {
return (
mapping !== null && typeof mapping === "object" && !Array.isArray(mapping)
);
}
/**
* @param {string|undefined} remainingRequest remaining request when folder mapping, undefined for file mappings
* @param {boolean} subpathMapping true, for subpath mappings
* @param {DirectMapping|null} mappingTarget direct export
* @param {Set<string>} conditionNames condition names
* @param {(d: string, f: boolean) => void} assert asserting direct value
* @returns {string[]} mapping result
*/
function directMapping(
remainingRequest,
subpathMapping,
mappingTarget,
conditionNames,
assert
) {
if (mappingTarget === null) return [];
if (typeof mappingTarget === "string") {
return [
targetMapping(remainingRequest, subpathMapping, mappingTarget, assert)
];
}
const targets = [];
for (const exp of mappingTarget) {
if (typeof exp === "string") {
targets.push(
targetMapping(remainingRequest, subpathMapping, exp, assert)
);
continue;
}
const mapping = conditionalMapping(exp, conditionNames);
if (!mapping) continue;
const innerExports = directMapping(
remainingRequest,
subpathMapping,
mapping,
conditionNames,
assert
);
for (const innerExport of innerExports) {
targets.push(innerExport);
}
}
return targets;
}
/**
* @param {string|undefined} remainingRequest remaining request when folder mapping, undefined for file mappings
* @param {boolean} subpathMapping true, for subpath mappings
* @param {string} mappingTarget direct export
* @param {(d: string, f: boolean) => void} assert asserting direct value
* @returns {string} mapping result
*/
function targetMapping(
remainingRequest,
subpathMapping,
mappingTarget,
assert
) {
if (remainingRequest === undefined) {
assert(mappingTarget, false);
return mappingTarget;
}
if (subpathMapping) {
assert(mappingTarget, true);
return mappingTarget + remainingRequest;
}
assert(mappingTarget, false);
return mappingTarget.replace(/\*/g, remainingRequest.replace(/\$/g, "$$"));
}
/**
* @param {ConditionalMapping} conditionalMapping_ conditional mapping
* @param {Set<string>} conditionNames condition names
* @returns {DirectMapping|null} direct mapping if found
*/
function conditionalMapping(conditionalMapping_, conditionNames) {
/** @type {[ConditionalMapping, string[], number][]} */
let lookup = [[conditionalMapping_, Object.keys(conditionalMapping_), 0]];
loop: while (lookup.length > 0) {
const [mapping, conditions, j] = lookup[lookup.length - 1];
const last = conditions.length - 1;
for (let i = j; i < conditions.length; i++) {
const condition = conditions[i];
// assert default. Could be last only
if (i !== last) {
if (condition === "default") {
throw new Error("Default condition should be last one");
}
} else if (condition === "default") {
const innerMapping = mapping[condition];
// is nested
if (isConditionalMapping(innerMapping)) {
const conditionalMapping = /** @type {ConditionalMapping} */ (innerMapping);
lookup[lookup.length - 1][2] = i + 1;
lookup.push([conditionalMapping, Object.keys(conditionalMapping), 0]);
continue loop;
}
return /** @type {DirectMapping} */ (innerMapping);
}
if (conditionNames.has(condition)) {
const innerMapping = mapping[condition];
// is nested
if (isConditionalMapping(innerMapping)) {
const conditionalMapping = /** @type {ConditionalMapping} */ (innerMapping);
lookup[lookup.length - 1][2] = i + 1;
lookup.push([conditionalMapping, Object.keys(conditionalMapping), 0]);
continue loop;
}
return /** @type {DirectMapping} */ (innerMapping);
}
}
lookup.pop();
}
return null;
}
/**
* Internal helper to create path tree node
* to ensure that each node gets the same hidden class
* @returns {PathTreeNode} node
*/
function createNode() {
return {
children: null,
folder: null,
wildcards: null,
files: new Map()
};
}
/**
* Internal helper for building path tree
* @param {PathTreeNode} root root
* @param {string} path path
* @param {MappingValue} target target
*/
function walkPath(root, path, target) {
if (path.length === 0) {
root.folder = target;
return;
}
let node = root;
// Typical path tree can looks like
// root
// - files: ["a.js", "b.js"]
// - children:
// node1:
// - files: ["a.js", "b.js"]
let lastNonSlashIndex = 0;
let slashIndex = path.indexOf("/", 0);
while (slashIndex !== -1) {
const folder = path.slice(lastNonSlashIndex, slashIndex);
let newNode;
if (node.children === null) {
newNode = createNode();
node.children = new Map();
node.children.set(folder, newNode);
} else {
newNode = node.children.get(folder);
if (!newNode) {
newNode = createNode();
node.children.set(folder, newNode);
}
}
node = newNode;
lastNonSlashIndex = slashIndex + 1;
slashIndex = path.indexOf("/", lastNonSlashIndex);
}
if (lastNonSlashIndex >= path.length) {
node.folder = target;
} else {
const file = lastNonSlashIndex > 0 ? path.slice(lastNonSlashIndex) : path;
if (file.endsWith("*")) {
if (node.wildcards === null) node.wildcards = new Map();
node.wildcards.set(file.slice(0, -1), target);
} else {
node.files.set(file, target);
}
}
}
/**
* @param {ExportsField} field exports field
* @returns {PathTreeNode} tree root
*/
function buildExportsFieldPathTree(field) {
const root = createNode();
// handle syntax sugar, if exports field is direct mapping for "."
if (typeof field === "string") {
root.files.set("", field);
return root;
} else if (Array.isArray(field)) {
root.files.set("", field.slice());
return root;
}
const keys = Object.keys(field);
for (let i = 0; i < keys.length; i++) {
const key = keys[i];
if (key.charCodeAt(0) !== dotCode) {
// handle syntax sugar, if exports field is conditional mapping for "."
if (i === 0) {
while (i < keys.length) {
const charCode = keys[i].charCodeAt(0);
if (charCode === dotCode || charCode === slashCode) {
throw new Error(
`Exports field key should be relative path and start with "." (key: ${JSON.stringify(
key
)})`
);
}
i++;
}
root.files.set("", field);
return root;
}
throw new Error(
`Exports field key should be relative path and start with "." (key: ${JSON.stringify(
key
)})`
);
}
if (key.length === 1) {
root.files.set("", field[key]);
continue;
}
if (key.charCodeAt(1) !== slashCode) {
throw new Error(
`Exports field key should be relative path and start with "./" (key: ${JSON.stringify(
key
)})`
);
}
walkPath(root, key.slice(2), field[key]);
}
return root;
}
/**
* @param {ImportsField} field imports field
* @returns {PathTreeNode} root
*/
function buildImportsFieldPathTree(field) {
const root = createNode();
const keys = Object.keys(field);
for (let i = 0; i < keys.length; i++) {
const key = keys[i];
if (key.charCodeAt(0) !== hashCode) {
throw new Error(
`Imports field key should start with "#" (key: ${JSON.stringify(key)})`
);
}
if (key.length === 1) {
throw new Error(
`Imports field key should have at least 2 characters (key: ${JSON.stringify(
key
)})`
);
}
if (key.charCodeAt(1) === slashCode) {
throw new Error(
`Imports field key should not start with "#/" (key: ${JSON.stringify(
key
)})`
);
}
walkPath(root, key.slice(1), field[key]);
}
return root;
}