update to 5.0.3 -- `Right-hand side of 'instanceof' is not callable`

hi there, the recent update from 5.0.2 to 5.0.3 broke the build on a project of mine.

here’s the error that we’re getting:

webpack-bundle-0674cf6….js:8 Uncaught TypeError: Right-hand side of 'instanceof' is not callable
    at o (webpack-bundle-0674cf6….js:8)
    at Object.run (webpack-bundle-0674cf6….js:8)
    at c.initSelector (webpack-bundle-0674cf6….js:8)
    at new c (webpack-bundle-0674cf6….js:8)
    at f._constructComponentWithoutOwner (webpack-bundle-0674cf6….js:7)
    at f._constructComponent (webpack-bundle-0674cf6….js:7)
    at f.mountComponent (webpack-bundle-0674cf6….js:7)
    at Object.mountComponent (webpack-bundle-0674cf6….js:5)
    at f.performInitialMount (webpack-bundle-0674cf6….js:7)
    at f.mountComponent (webpack-bundle-0674cf6….js:7)

apologies for the lack of detail, let me know if there’s anything i can do to clarify. thx!

[dule]

We just ran into this error, which appears to be from a bad minification of redux. In our case, it was the result of uglifying already minified code.

This piece of code:

function makeSelectorStateful(sourceSelector, store) {
  // wrap the selector in an object that tracks its results between runs.
  const selector = {
    run: function runComponentSelector(props) {
      try {
        const nextProps = sourceSelector(store.getState(), props)
        if (nextProps !== selector.props || selector.error) {
          selector.shouldComponentUpdate = true
          selector.props = nextProps
          selector.error = null
        }
      } catch (error) {
        selector.shouldComponentUpdate = true
        selector.error = error
      }
    }
  }

minified to:

        function c(e, t) {
            var o = {
                run: function(n) {
                    try {
                        var r = e(t.getState(), n);
                        (r !== o.props || o.error) && (o.shouldComponentUpdate = !0,
                        o.props = r,
                        o.error = null)
                    } catch (s) {
                        o.shouldComponentUpdate = !0,
                        o.error = s
                    }
                }
            };
            return o
        }

and then on the second pass of uglifying became:

        function c(e, t) {
            var o = {
                run: function(e) {
                    try {
                        var n = r(t.getState(), e);
                        (n !== o.props || o.error) && (o.shouldComponentUpdate = !0,
                        o.props = n,
                        o.error = null)
                    } catch (r) {
                        o.shouldComponentUpdate = !0,
                        o.error = r
                    }
                }
            };
            return o
        }

… r in var n = r(t.getState(), e);, which should have been the same variable as e in the top-level function now pointed to this function:

        function r(e, t) {
            if (!(e instanceof t))
                throw new TypeError("Cannot call a class as a function")
        }

which is this function:

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

I don’t understand how the minifier could mangle this so badly, but it caused a completely random call into _classCallCheck which is what was throwing our error. Removing the second uglify fixed our problem.

[data-doge]

@okmttdhr

ey, we just locked react-redux to 5.0.2 and moved on.

wish i could be more helpful!