Change Request: Add isGlobalReference() to SourceCode

[nzakas]

Which packages would you like to change?

• espree
• eslint-scope
• eslint-visitor-keys

What problem do you want to solve?

There are a lot of ESLint rules that need to determine if a given identifier refers to a global or not. As a result, we have multiple copies of functions that try to determine if an identifier refers to a global:
https://github.com/search?q=repo%3Aeslint%2Feslint%20isglobal&type=code

That also means plugin rules need to implement their own.

What do you think is the correct solution?

I think this is common enough that we should add a isGlobalReference() method to ScopeManager SourceCode to encapsulate this functionality:

const isGlobal = sourceCode.isGlobalScope(node);

I think the method should accept a node and then determine from that node if it contains a reference to a global variable. Basically, we can copy the code from here:

eslint/lib/rules/prefer-regex-literals.js

Lines 175 to 184 in e62e267

	function isGlobalReference(node) {
	const scope = sourceCode.getScope(node);
	const variable = findVariable(scope, node);
	return (
	variable !== null &&
	variable.scope.type === "global" &&
	variable.defs.length === 0
	);
	}

Then maybe we could expose the method on SourceCode to make it easier for rules to access.

Participation

• I am willing to submit a pull request for this change.

Additional comments

Looking for a volunteer to take this on.

[nzakas]

Actually, maybe it would be better to just add isGlobalReference() directly to SourceCode and not worry about adding it to this package?

[snitin315]

I'm in favor, will work on this.

[nzakas]

@snitin315 for API changes we need the TSC to approve, so let's see what @eslint/eslint-tsc thinks.