match-path-async.js
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"use strict";
Object.defineProperty(exports, "__esModule", { value: true });
var path = require("path");
var TryPath = require("./try-path");
var MappingEntry = require("./mapping-entry");
var Filesystem = require("./filesystem");
/**
* See the sync version for docs.
*/
function createMatchPathAsync(absoluteBaseUrl, paths, mainFields, addMatchAll) {
if (mainFields === void 0) { mainFields = ["main"]; }
if (addMatchAll === void 0) { addMatchAll = true; }
var absolutePaths = MappingEntry.getAbsoluteMappingEntries(absoluteBaseUrl, paths, addMatchAll);
return function (requestedModule, readJson, fileExists, extensions, callback) {
return matchFromAbsolutePathsAsync(absolutePaths, requestedModule, readJson, fileExists, extensions, callback, mainFields);
};
}
exports.createMatchPathAsync = createMatchPathAsync;
/**
* See the sync version for docs.
*/
function matchFromAbsolutePathsAsync(absolutePathMappings, requestedModule, readJson, fileExists, extensions, callback, mainFields) {
if (readJson === void 0) { readJson = Filesystem.readJsonFromDiskAsync; }
if (fileExists === void 0) { fileExists = Filesystem.fileExistsAsync; }
if (extensions === void 0) { extensions = Object.keys(require.extensions); }
if (mainFields === void 0) { mainFields = ["main"]; }
var tryPaths = TryPath.getPathsToTry(extensions, absolutePathMappings, requestedModule);
if (!tryPaths) {
return callback();
}
findFirstExistingPath(tryPaths, readJson, fileExists, callback, 0, mainFields);
}
exports.matchFromAbsolutePathsAsync = matchFromAbsolutePathsAsync;
function findFirstExistingMainFieldMappedFile(packageJson, mainFields, packageJsonPath, fileExistsAsync, doneCallback, index) {
if (index === void 0) { index = 0; }
if (index >= mainFields.length) {
return doneCallback(undefined, undefined);
}
var tryNext = function () {
return findFirstExistingMainFieldMappedFile(packageJson, mainFields, packageJsonPath, fileExistsAsync, doneCallback, index + 1);
};
var mainFieldMapping = packageJson[mainFields[index]];
if (typeof mainFieldMapping !== "string") {
// Skip mappings that are not pointers to replacement files
return tryNext();
}
var mappedFilePath = path.join(path.dirname(packageJsonPath), mainFieldMapping);
fileExistsAsync(mappedFilePath, function (err, exists) {
if (err) {
return doneCallback(err);
}
if (exists) {
return doneCallback(undefined, mappedFilePath);
}
return tryNext();
});
}
// Recursive loop to probe for physical files
function findFirstExistingPath(tryPaths, readJson, fileExists, doneCallback, index, mainFields) {
if (index === void 0) { index = 0; }
if (mainFields === void 0) { mainFields = ["main"]; }
var tryPath = tryPaths[index];
if (tryPath.type === "file" ||
tryPath.type === "extension" ||
tryPath.type === "index") {
fileExists(tryPath.path, function (err, exists) {
if (err) {
return doneCallback(err);
}
if (exists) {
// Not sure why we don't just return the full path? Why strip it?
return doneCallback(undefined, TryPath.getStrippedPath(tryPath));
}
if (index === tryPaths.length - 1) {
return doneCallback();
}
// Continue with the next path
return findFirstExistingPath(tryPaths, readJson, fileExists, doneCallback, index + 1, mainFields);
});
}
else if (tryPath.type === "package") {
readJson(tryPath.path, function (err, packageJson) {
if (err) {
return doneCallback(err);
}
if (packageJson) {
return findFirstExistingMainFieldMappedFile(packageJson, mainFields, tryPath.path, fileExists, function (mainFieldErr, mainFieldMappedFile) {
if (mainFieldErr) {
return doneCallback(mainFieldErr);
}
if (mainFieldMappedFile) {
// Not sure why we don't just return the full path? Why strip it?
return doneCallback(undefined, Filesystem.removeExtension(mainFieldMappedFile));
}
// No field in package json was a valid option. Continue with the next path.
return findFirstExistingPath(tryPaths, readJson, fileExists, doneCallback, index + 1, mainFields);
});
}
// This is async code, we need to return unconditionally, otherwise the code still falls
// through and keeps recursing. While this might work in general, libraries that use neo-async
// like Webpack will actually not allow you to call the same callback twice.
//
// An example of where this caused issues:
// https://github.com/dividab/tsconfig-paths-webpack-plugin/issues/11
//
// Continue with the next path
return findFirstExistingPath(tryPaths, readJson, fileExists, doneCallback, index + 1, mainFields);
});
}
else {
TryPath.exhaustiveTypeException(tryPath.type);
}
}