custom-test-env.js

const Environment = require("jest-environment-jsdom");

/**
 * A custom environment to set the TextEncoder that is required by TensorFlow.js.
 */
module.exports = class CustomTestEnvironment extends Environment {
    async setup() {
        await super.setup();
        if (typeof this.global.TextEncoder === "undefined") {
            const { TextEncoder } = require("util");
            this.global.TextEncoder = TextEncoder;
        }
        if (typeof this.global.TextDecoder === "undefined") {
            const { TextDecoder } = require("util");
            this.global.TextDecoder = TextDecoder;
        }
    }
};