docx-processing.js

[...]

docx.init({
    ND_DEV_ID: "",    // goto https://developers.nativedocuments.com/ to get a dev-id/dev-secret
    ND_DEV_SECRET: "", // you can also set the credentials in the enviroment variables
    ENVIRONMENT: "NODE", // required
    LAZY_INIT: true      // if set to false the WASM engine will be initialized right now, usefull pre-caching (like e.g. for AWS lambda)
}).catch(function (e) {
    console.error(e);
});

async function convertHelper(document, exportFct) {
    const api = await docx.engine();
    await api.load(document);
    const arrayBuffer = await api[exportFct]();
    await api.close();
    return arrayBuffer;
}

router.get("/", function (req, res) {
    const params = { Bucket: 'mybucket', Key: 'test.docx' };
    s3.getObject(params, function (err, data) {
        if (err) console.log(err, err.stack); // an error occurred
        else {
            convertHelper(new Uint8Array(data), "exportPDF").then((arrayBuffer) => {
                fs.writeFileSync("out.pdf", new Uint8Array(arrayBuffer));
                res.send("OK");
            }).catch((e) => {
                console.error(e);
                res.send("ERROR: " + e)
            });
        };           // successful response
    });
});