Misleading error in Internet Explorer 11

[brunoabreu]

It throws the following error:

SCRIPT5022: Cannot use undefined "Boolean" from another module or realm. Ensure that there is only one instance of "graphql" in the node_modules directory. If different versions of "graphql" are the dependencies of other relied on modules, use "resolutions" to ensure only one version is installed. https://yarnpkg.com/en/docs/selective-version-resolutions Duplicate "graphql" modules cannot be used at the same time since different versions may have different capabilities and behavior. The data from one version used in the function from another could produce confusing and spurious results.

Turns out this happens because this code compares two function names:

graphql-js/src/jsutils/instanceOf.js

Lines 33 to 36 in f3ebab8

	const className = constructor.name;
	if (valueClass && valueClass.name === className) {
	throw new Error(
	`Cannot use ${className} "${value}" from another module or realm.

Internet Explorer does not have support to Function.name. Thus the comparison will be undefined === undefined.

In my case, I fixed that by adding a polyfill. But I think this behavior is, at least, very confusing.