How to use the is-typedarray function in is-typedarray

export function convert_dates(value) {
    // check if the array of value contains Date objects, if so
    // dates are serialized using the timestamp only, some parts of the code
    // use the Data objects, detect that and convert.
    // also, we set the .type property of TypedArray, to keep track of it being a
    // date array
    if(isTypedArray(value))
        return value;
    const convert_to_date = function(x) {
        const ar: any = new Float64Array(x.map(Number));
        ar.type = 'date';
        return ar;
    }
    if(value[0] instanceof Array && value[0][0] instanceof Date)
        value = value.map(convert_to_date);
    else if(value[0] instanceof Date)
        value = convert_to_date(value);
    return value;
}

export function deepCopy(obj) {
    // This makes a deep copy of JSON-parsable objects
    // (no cycling or recombining)
    // Backbone model attributes must be JSON parsable. Hence there is
    // no need for a fancier logic, and it is surprisingly efficient.
    if(isTypedArray(obj))
        return obj.slice()
    else if(_.isArray(obj)) {
        return obj.map(x => deepCopy(x))
    } else if(_.isNumber(obj) || _.isString(obj)) {
        return obj;
    } else if(_.isDate(obj)) {
        return new Date(obj.getTime());
    } else {
        const newobj = {}
        for(let key in obj) {
            if(obj.hasOwnProperty(key)) {
                newobj[key] = deepCopy(obj[key])
            }
        }
        return newobj;
    }

function serialize_array_or_json(data, manager) {
    if(data == null)
        return null;
    if(_.isNumber(data)) {
        return data; // return numbers directly
    } else if(_.isArray(data)) {
        return data.map((ar) => serialize_array_or_json(ar, manager))
    } else if(isTypedArray(data)) {
        return serialize_typed_array(data, manager)
    }
}

context(({position, rotation, scale}) => {
      ok(position, "Position context variable is defined.")
      ok(isTypedArray(position), "Position context variable is an array.")
      ok(3 == position.length, "Position context variable is an array with 3 components.")
      ok(false == hasDiff(position, expected.position), "Position context variable has correct value from initial state.")

      ok(scale, "Scale context variable is defined.")
      ok(isTypedArray(scale), "Scale context variable is an array.")
      ok(3 == scale.length, "Scale context variable is an array with 3 components.")
      ok(false == hasDiff(scale, expected.scale), "Scale context variable has correct value from initial state.")

      ok(rotation, "Rotation context variable is defined.")
      ok(isTypedArray(rotation), "Rotation context variable is an array.")
      ok(4 == rotation.length, "Rotation context variable is an array with 3 components.")
      ok(false == hasDiff(rotation, expected.rotation), "Rotation context variable has correct value from initial state.")

    })
    end()

trs(({position, rotation, scale}) => {

      ok(position, "Position context variable is defined.")
      ok(isTypedArray(position), "Position context variable is an array.")
      ok(3 == position.length, "Position context variable is an array with 3 components.")
      ok(false == hasDiff(position, defaults.position), "Position context variable has correct default value.")

      ok(scale, "Scale context variable is defined.")
      ok(isTypedArray(scale), "Scale context variable is an array.")
      ok(3 == scale.length, "Scale context variable is an array with 3 components.")
      ok(false == hasDiff(scale, defaults.scale), "Scale context variable has correct default value.")

      ok(rotation, "Rotation context variable is defined.")
      ok(isTypedArray(rotation), "Rotation context variable is an array.")
      ok(4 == rotation.length, "Rotation context variable is an array with 3 components.")
      ok(false == hasDiff(rotation, defaults.rotation), "Rotation context variable has correct default value.")

    })
    end()

context(({localMatrix, transformMatrix}) => {

      ok(localMatrix, "Local matrix context variable is defined.")
      ok(isTypedArray(localMatrix) || localMatrix instanceof Float32Array, "Local matrix context variable is an array.")
      ok(16 == localMatrix.length, "Local matrix context variable is an array with 16 components.")

      ok(transformMatrix, "Transform matrix context variable is defined.")
      ok(isTypedArray(transformMatrix) || transformMatrix instanceof Float32Array, "Transform context variable is an array.")
      ok(16 == transformMatrix.length, "Transform matrix context variable is an array with 16 components.")

    })
    end()

context(({position, rotation, scale}) => {

      ok(position, "Position context variable is defined.")
      ok(isTypedArray(position), "Position context variable is an array.")
      ok(3 == position.length, "Position context variable is an array with 3 components.")
      ok(false == hasDiff(position, defaults.position), "Position context variable has correct default value.")

      ok(scale, "Scale context variable is defined.")
      ok(isTypedArray(scale), "Scale context variable is an array.")
      ok(3 == scale.length, "Scale context variable is an array with 3 components.")
      ok(false == hasDiff(scale, defaults.scale), "Scale context variable has correct default value.")

      ok(rotation, "Rotation context variable is defined.")
      ok(isTypedArray(rotation), "Rotation context variable is an array.")
      ok(4 == rotation.length, "Rotation context variable is an array with 3 components.")
      ok(false == hasDiff(rotation, defaults.rotation), "Rotation context variable has correct default value.")

    })
    end()

trs(expected, ({position, rotation, scale}) => {

      ok(position, "Position context variable is defined.")
      ok(isTypedArray(position), "Position context variable is an array.")
      ok(3 == position.length, "Position context variable is an array with 3 components.")
      ok(false == hasDiff(position, expected.position), "Position context variable has correct value from input arguments.")

      ok(scale, "Scale context variable is defined.")
      ok(isTypedArray(scale), "Scale context variable is an array.")
      ok(3 == scale.length, "Scale context variable is an array with 3 components.")
      ok(false == hasDiff(scale, expected.scale), "Scale context variable has correct value from input arguments.")

      ok(rotation, "Rotation context variable is defined.")
      ok(isTypedArray(rotation), "Rotation context variable is an array.")
      ok(4 == rotation.length, "Rotation context variable is an array with 3 components.")
      ok(false == hasDiff(rotation, expected.rotation), "Rotation context variable has correct value from input arguments.")

    })
    end()

({ok, end}) => {
    const {scale} = defaults
    ok('scale' in defaults, "Exists in defaults object.")
    ok(isTypedArray(scale), "Is an array.")
    ok(3 == scale.length, "Has 3 components.")
    ok(false == hasDiff(scale, [1,1,1]), "Is identity scale vector.")
    end()
  })