@expo/image-utils
Version:
A package used by Expo CLI for processing images
68 lines • 2.96 kB
JavaScript
;
var __importDefault = (this && this.__importDefault) || function (mod) {
return (mod && mod.__esModule) ? mod : { "default": mod };
};
Object.defineProperty(exports, "__esModule", { value: true });
exports.downloadOrUseCachedImage = downloadOrUseCachedImage;
exports.downloadImage = downloadImage;
const fs_1 = __importDefault(require("fs"));
// @ts-ignore
const jimp_compact_1 = __importDefault(require("jimp-compact"));
const path_1 = __importDefault(require("path"));
const stream_1 = __importDefault(require("stream"));
const temp_dir_1 = __importDefault(require("temp-dir"));
const unique_string_1 = __importDefault(require("unique-string"));
const util_1 = __importDefault(require("util"));
// cache downloaded images into memory
const cacheDownloadedKeys = {};
function stripQueryParams(url) {
return url.split('?')[0].split('#')[0];
}
function temporaryDirectory() {
const directory = path_1.default.join(temp_dir_1.default, (0, unique_string_1.default)());
fs_1.default.mkdirSync(directory, { recursive: true });
return directory;
}
async function downloadOrUseCachedImage(url) {
if (url in cacheDownloadedKeys) {
return cacheDownloadedKeys[url];
}
if (url.startsWith('http')) {
cacheDownloadedKeys[url] = await downloadImage(url);
}
else {
cacheDownloadedKeys[url] = url;
}
return cacheDownloadedKeys[url];
}
async function downloadImage(url) {
const outputPath = temporaryDirectory();
const response = await fetch(url);
if (!response.ok) {
throw new Error(`It was not possible to download image from '${url}'`);
}
if (!response.body) {
throw new Error(`No response received from '${url}'`);
}
// Download to local file
const streamPipeline = util_1.default.promisify(stream_1.default.pipeline);
const localPath = path_1.default.join(outputPath, path_1.default.basename(stripQueryParams(url)));
// Type casting is required, see: https://github.com/DefinitelyTyped/DefinitelyTyped/discussions/65542
const readableBody = stream_1.default.Readable.fromWeb(response.body);
await streamPipeline(readableBody, fs_1.default.createWriteStream(localPath));
// If an image URL doesn't have a name, get the mime type and move the file.
const img = await jimp_compact_1.default.read(localPath);
const mime = img.getMIME().split('/').pop();
if (!localPath.endsWith(mime)) {
const newPath = path_1.default.join(outputPath, `image.${mime}`);
const parentPath = path_1.default.dirname(newPath);
if (!fs_1.default.existsSync(parentPath)) {
await fs_1.default.promises.mkdir(parentPath, { recursive: true });
}
// NOTE: EXDEV can't happen since we're just renaming the file in the same directory
await fs_1.default.promises.rename(localPath, newPath);
return newPath;
}
return localPath;
}
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