>UPDATE3. Fixed that error as well using JSON instead.
>
>UPDATE2. Now after I fixed find and findIndex to use _lodash methods it's complaining about
>
> let clone = Object.assign({}, $scope.currentIitem);
>
>:(((
>
>I would need to find IE compatible code now.
>
>
>UPDATE. The error does seem to be find and findIndex methods for arrays. I fixed find in one place, now it complains about findIndex in another. The error comes from compilation, as that piece of code is not even called.
>
>I am fixing using _lodash.js now.
>
>Hi everybody,
>
>I re-factored smAdvancedSearch directive and it works fine in Chrome. However, in IE I'm getting an error on the line which is not even supposed to be called until the search filters are added, so it's weird:
>
>

>/**
>         * get Operator Description
>         * @params {string} strOp
>         * @returns string description 
>         */
>    controller.prototype.getOperatorDescription = function (strOp) {
>        if (_.isObject(this.field) && this.field.possibleOperators)
>            return this.field.possibleOperators.find(x => x.key === strOp).value;
>        else
>            return strOp;
>    };

>
>The line with the find seems to return an error. Could it be that IE doesn't have array.find method and thus this error?
>
>What else could it be and how should I correct the issue?
>
>Thanks in advance.

IE 11 has virtually NO support for ES6 - see https://kangax.github.io/compat-table/es6/ (and MS support has ended so it probably never will). Edge, OTOH, has if pretty much fully ES6 compliant.

Personally I don't even try to support IE - but they are not 'public' sites and we can specify/recommend which browsers can/should be used. If you really have to support IE11 then probably best stick to ES5 (with Typescript) ?