streaming/transformer.js

Transforms and other streaming helpers

"use strict";
var __extends = (this && this.__extends) || (function () {
    var extendStatics = function (d, b) {
        extendStatics = Object.setPrototypeOf ||
            ({ __proto__: [] } instanceof Array && function (d, b) { d.__proto__ = b; }) ||
            function (d, b) { for (var p in b) if (Object.prototype.hasOwnProperty.call(b, p)) d[p] = b[p]; };
        return extendStatics(d, b);
    };
    return function (d, b) {
        if (typeof b !== "function" && b !== null)
            throw new TypeError("Class extends value " + String(b) + " is not a constructor or null");
        extendStatics(d, b);
        function __() { this.constructor = d; }
        d.prototype = b === null ? Object.create(b) : (__.prototype = b.prototype, new __());
    };
})();
Object.defineProperty(exports, "__esModule", { value: true });
exports.Transformer = void 0;
var stream_1 = require("stream");
/** Like Mapper, but more bare-bones. The predicate function has to call a
given callback, which means the processing code can be async.

`this` is bound to the stream object inside the transform function, so you
can use `this.push(...)` to output multiple chunks per single input chunk.

Example:

    new streaming.Transformer(function(chunk, encoding, callback) {
      setTimeout(() => {
        this.push('...');
        this.push(chunk);
        callback();
      }, 1000);
    }, {objectMode: true});

*/
var Transformer = /** @class */ (function (_super) {
    __extends(Transformer, _super);
    function Transformer(transformFn, options) {
        var _this = _super.call(this, options) || this;
        _this._transform = transformFn.bind(_this);
        return _this;
    }
    return Transformer;
}(stream_1.Transform));
exports.Transformer = Transformer;