Method recommendVersion

src/core/qrcode/encoder/Encoder.ts:174–187

* Decides the smallest version of QR code that will contain all of the provided data. * * @throws WriterException if the data cannot fit in any version

(ecLevel: ErrorCorrectionLevel,
        mode: Mode,
        headerBits: BitArray,
        dataBits: BitArray)

     * @throws WriterException if the data cannot fit in any version
     */
    private static recommendVersion(ecLevel: ErrorCorrectionLevel,
        mode: Mode,
        headerBits: BitArray,
        dataBits: BitArray): Version /*throws WriterException*/ {
        // Hard part: need to know version to know how many bits length takes. But need to know how many
        // bits it takes to know version. First we take a guess at version by assuming version will be
        // the minimum, 1:
        const provisionalBitsNeeded = this.calculateBitsNeeded(mode, headerBits, dataBits, Version.getVersionForNumber(1));
        const provisionalVersion = this.chooseVersion(provisionalBitsNeeded, ecLevel);

        // Use that guess to calculate the right version. I am still not sure this works in 100% of cases.
        const bitsNeeded = this.calculateBitsNeeded(mode, headerBits, dataBits, provisionalVersion);
        return this.chooseVersion(bitsNeeded, ecLevel);
    }

    private static calculateBitsNeeded(mode: Mode,
        headerBits: BitArray,