Function tryGetModuleNameAsNodeModule

test/fixtures/snapshot/typescript.js:122487–122600

(_a, _b, importingSourceFile, host, options, userPreferences, packageNameOnly, overrideMode)

                : ts.removeFileExtension(relativePath);
        }
        function tryGetModuleNameAsNodeModule(_a, _b, importingSourceFile, host, options, userPreferences, packageNameOnly, overrideMode) {
            var path = _a.path, isRedirect = _a.isRedirect;
            var getCanonicalFileName = _b.getCanonicalFileName, sourceDirectory = _b.sourceDirectory;
            if (!host.fileExists || !host.readFile) {
                return undefined;
            }
            var parts = ts.getNodeModulePathParts(path);
            if (!parts) {
                return undefined;
            }
            // Simplify the full file path to something that can be resolved by Node.
            var moduleSpecifier = path;
            var isPackageRootPath = false;
            if (!packageNameOnly) {
                var preferences = getPreferences(host, userPreferences, options, importingSourceFile);
                var packageRootIndex = parts.packageRootIndex;
                var moduleFileName = void 0;
                while (true) {
                    // If the module could be imported by a directory name, use that directory's name
                    var _c = tryDirectoryWithPackageJson(packageRootIndex), moduleFileToTry = _c.moduleFileToTry, packageRootPath = _c.packageRootPath, blockedByExports = _c.blockedByExports, verbatimFromExports = _c.verbatimFromExports;
                    if (ts.getEmitModuleResolutionKind(options) !== ts.ModuleResolutionKind.Classic) {
                        if (blockedByExports) {
                            return undefined; // File is under this package.json, but is not publicly exported - there's no way to name it via `node_modules` resolution
                        }
                        if (verbatimFromExports) {
                            return moduleFileToTry;
                        }
                    }
                    if (packageRootPath) {
                        moduleSpecifier = packageRootPath;
                        isPackageRootPath = true;
                        break;
                    }
                    if (!moduleFileName)
                        moduleFileName = moduleFileToTry;
                    // try with next level of directory
                    packageRootIndex = path.indexOf(ts.directorySeparator, packageRootIndex + 1);
                    if (packageRootIndex === -1) {
                        moduleSpecifier = removeExtensionAndIndexPostFix(moduleFileName, preferences.ending, options, host);
                        break;
                    }
                }
            }
            if (isRedirect && !isPackageRootPath) {
                return undefined;
            }
            var globalTypingsCacheLocation = host.getGlobalTypingsCacheLocation && host.getGlobalTypingsCacheLocation();
            // Get a path that's relative to node_modules or the importing file's path
            // if node_modules folder is in this folder or any of its parent folders, no need to keep it.
            var pathToTopLevelNodeModules = getCanonicalFileName(moduleSpecifier.substring(0, parts.topLevelNodeModulesIndex));
            if (!(ts.startsWith(sourceDirectory, pathToTopLevelNodeModules) || globalTypingsCacheLocation && ts.startsWith(getCanonicalFileName(globalTypingsCacheLocation), pathToTopLevelNodeModules))) {
                return undefined;
            }
            // If the module was found in @types, get the actual Node package name
            var nodeModulesDirectoryName = moduleSpecifier.substring(parts.topLevelPackageNameIndex + 1);
            var packageName = ts.getPackageNameFromTypesPackageName(nodeModulesDirectoryName);
            // For classic resolution, only allow importing from node_modules/@types, not other node_modules
            return ts.getEmitModuleResolutionKind(options) === ts.ModuleResolutionKind.Classic && packageName === nodeModulesDirectoryName ? undefined : packageName;