src/worker-helper.ts


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import { PDFWorkerMessage } from "./worker";
import { PDFWorker } from "../dist/cache/worker";

const scriptUrlFromFunction = (fn: () => any): string => {
    const blob = new Blob(["(" + fn.toString() + ")()"], {
        type: "application/javascript",
    });
    return window.URL.createObjectURL(blob);
};

// Node.js fix
if (typeof Worker === "undefined") {
    globalThis.Worker = class {} as any; // noop shim
}

export class PDFWorkerHelper extends Worker {
    constructor() {
        const url = scriptUrlFromFunction(PDFWorker);
        super(url);
    }

    generatePDF(
        imgURLs: string[],
        imgType: "svg" | "png",
        width: number,
        height: number
    ): Promise<ArrayBuffer> {
        const msg: PDFWorkerMessage = [imgURLs, imgType, width, height];
        this.postMessage(msg);
        return new Promise((resolve) => {
            this.addEventListener("message", (e) => {
                resolve(e.data);
            });
        });
    }
}