serverless-spy
Version:
CDK-based library for writing elegant integration tests on AWS serverless architecture and an additional web console to monitor events in real time.
47 lines (46 loc) • 1.66 kB
JavaScript
;
Object.defineProperty(exports, "__esModule", { value: true });
exports.headStream = void 0;
const stream_1 = require("stream");
const headStream_browser_1 = require("./headStream.browser");
const stream_type_check_1 = require("./stream-type-check");
const headStream = (stream, bytes) => {
if ((0, stream_type_check_1.isReadableStream)(stream)) {
return (0, headStream_browser_1.headStream)(stream, bytes);
}
return new Promise((resolve, reject) => {
const collector = new Collector();
collector.limit = bytes;
stream.pipe(collector);
stream.on("error", (err) => {
collector.end();
reject(err);
});
collector.on("error", reject);
collector.on("finish", function () {
const bytes = new Uint8Array(Buffer.concat(this.buffers));
resolve(bytes);
});
});
};
exports.headStream = headStream;
class Collector extends stream_1.Writable {
constructor() {
super(...arguments);
this.buffers = [];
this.limit = Infinity;
this.bytesBuffered = 0;
}
_write(chunk, encoding, callback) {
var _a;
this.buffers.push(chunk);
this.bytesBuffered += (_a = chunk.byteLength) !== null && _a !== void 0 ? _a : 0;
if (this.bytesBuffered >= this.limit) {
const excess = this.bytesBuffered - this.limit;
const tailBuffer = this.buffers[this.buffers.length - 1];
this.buffers[this.buffers.length - 1] = tailBuffer.subarray(0, tailBuffer.byteLength - excess);
this.emit("finish");
}
callback();
}
}