No longer ES5 compatible due to use of Symbol

[Schnark]

The documentation says that math.js is still ES5 compatible. But trying to execute it in an old browser throws errors, because Symbol is undefined (which is ES6). Actually, Symbol is used in many places in the library, but in most cases there is a check to see whether it exists before it is accessed, but in three places this check is missing. As far as I can see (such old browsers aren't good for debugging, I am only told all 3 instances are in line 40 of https://cdnjs.cloudflare.com/ajax/libs/mathjs/9.4.2/math.js), these are the 3 instances: https://github.com/josdejong/mathjs/search?q=Symbol.iterator (Matrix, SparseMatrix, DenseMatrix)

Either you should guard them with a check for typeof Symbol !== 'undefined', or update the documentation to say that an ES6 compliant browser is required.

[cshaa]

Hmm, this is weird... We are testing on Internet Explorer 11, Windows 10 (and the tests pass).
The Symbol.iterator parts should be polyfilled by Babel 🤔️

If you check the very beginning of the cjdns file, between

 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
 * WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
 * License for the specific language governing permissions and limitations under
 * the License.
 */

and

/**
 * @license Complex.js v2.0.13 12/05/2020
 *
 * Copyright (c) 2020, Robert Eisele (robert@xarg.org)
 * Dual licensed under the MIT or GPL Version 2 licenses.
 **/

you'll see there appears to be some kind of Symbol detection, but the minified code is quite opaque, so it's possible that the polyfill doesn't work correctly.

Thanks for reporting! On what browsers/versions/platforms did your tests fail?

[Schnark]

I tested this with an old Firefox, I assume something around version 20 (on an offline computer I sometimes use, so I currently can't tell you the exact version).

The code at the top of the file doesn't seem to be a polyfill for Symbol, but merely internal uses of Symbol provided it exists:

"undefined"!=typeof Symbol&&Symbol.toStringTag&&Object.defineProperty(e,Symbol.toStringTag,{value:"Module"})

just means: If Symbol is defined, and Symbol.toStringTag exists, then use it to output [object Module] when e is converted to a string.

[josdejong]

I've tested on IE 11, it indeed doesn't work with Symbol related errors:

So we should look into this, see whether it's fixable with babel (Or decide to drop support for IE if it's becoming to big of a headache (a bit too early maybe)

[josdejong]

It could be that the karma tests running on IE 11 are transpiled/bundled in a different way than the bundle math.min.js - it's odd that the tests succeed but the bundle doesn't work.

[josdejong]

@m93a are you able to look into this issue maybe?

[cshaa]

I'll see what I can do 👍

[cshaa]

I've created PR #2266 which should solve this problem, however I don't have any way to run IE11 to test it. @josdejong @Schnark Could you please build the PR, test it in IE11 and let me know if it worked?

Alternatively, instead of building you can just import this script: math.js.zip

[josdejong]

Fix published now in v9.4.4