exports.getFile = function()

in src/browser/FileProxy.js [136:205]
50 lines of code
21 McCabe index (conditional complexity)

        exports.getFile = function (successCallback, errorCallback, args) {
            const fullPath = args[0];
            let path = args[1];
            const options = args[2] || {};

            // Create an absolute path if we were handed a relative one.
            path = resolveToFullPath_(fullPath, path);

            idb_.get(path.storagePath, function (fileEntry) {
                if (options.create === true && options.exclusive === true && fileEntry) {
                    // If create and exclusive are both true, and the path already exists,
                    // getFile must fail.

                    if (errorCallback) {
                        errorCallback(FileError.PATH_EXISTS_ERR);
                    }
                } else if (options.create === true && !fileEntry) {
                    // If create is true, the path doesn't exist, and no other error occurs,
                    // getFile must create it as a zero-length file and return a corresponding
                    // FileEntry.
                    const newFileEntry = new FileEntry(path.fileName, path.fullPath, new FileSystem(path.fsName, fs_.root));

                    newFileEntry.file_ = new MyFile({
                        size: 0,
                        name: newFileEntry.name,
                        lastModifiedDate: new Date(),
                        storagePath: path.storagePath
                    });

                    idb_.put(newFileEntry, path.storagePath, successCallback, errorCallback);
                } else if (options.create === true && fileEntry) {
                    if (fileEntry.isFile) {
                        // Overwrite file, delete then create new.
                        idb_.delete(path.storagePath, function () {
                            const newFileEntry = new FileEntry(path.fileName, path.fullPath, new FileSystem(path.fsName, fs_.root));

                            newFileEntry.file_ = new MyFile({
                                size: 0,
                                name: newFileEntry.name,
                                lastModifiedDate: new Date(),
                                storagePath: path.storagePath
                            });

                            idb_.put(newFileEntry, path.storagePath, successCallback, errorCallback);
                        }, errorCallback);
                    } else {
                        if (errorCallback) {
                            errorCallback(FileError.INVALID_MODIFICATION_ERR);
                        }
                    }
                } else if ((!options.create || options.create === false) && !fileEntry) {
                    // If create is not true and the path doesn't exist, getFile must fail.
                    if (errorCallback) {
                        errorCallback(FileError.NOT_FOUND_ERR);
                    }
                } else if ((!options.create || options.create === false) && fileEntry &&
                    fileEntry.isDirectory) {
                    // If create is not true and the path exists, but is a directory, getFile
                    // must fail.
                    if (errorCallback) {
                        errorCallback(FileError.TYPE_MISMATCH_ERR);
                    }
                } else {
                    // Otherwise, if no other error occurs, getFile must return a FileEntry
                    // corresponding to path.

                    successCallback(fileEntryFromIdbEntry(fileEntry));
                }
            }, errorCallback);
        };