lib/rules/no-var.js
function isUsedFromOutsideOf(scopeNode) {

    /**
     * Checks whether a given reference is inside of the specified scope or not.
     *
     * @param {eslint-scope.Reference} reference - A reference to check.
     * @returns {boolean} `true` if the reference is inside of the specified
     *      scope.
     */
    function isOutsideOfScope(reference) {
        const scope = scopeNode.range;
        const id = reference.identifier.range;

        return id[0] < scope[0] || id[1] > scope[1];
    }

    return function(variable) {
        return variable.references.some(isOutsideOfScope);
    };
}
function isUsedFromOutsideOf(scopeNode) {

    /**
     * Checks whether a given reference is inside of the specified scope or not.
     *
     * @param {eslint-scope.Reference} reference - A reference to check.
     * @returns {boolean} `true` if the reference is inside of the specified
     *      scope.
     */
    function isOutsideOfScope(reference) {
        const scope = scopeNode.range;
        const id = reference.identifier.range;

        return id[0] < scope[0] || id[1] > scope[1];
    }

    return function(variable) {
        return variable.references.some(isOutsideOfScope);
    };
}
function isUsedFromOutsideOf ( scopeNode ) { /**
     * Checks whether a given reference is inside of the specified scope or not.
     *
     * @param {eslint-scope.Reference} reference - A reference to check.
     * @returns {boolean} `true` if the reference is inside of the specified
     *      scope.
     */ function isOutsideOfScope ( reference ) { const scope = scopeNode . range ; const id = reference . identifier . range ; return id [ 0 ] < scope [ 0 ] || id [ 1 ] > scope [ 1 ] ; } return function ( variable ) { return variable . references . some ( isOutsideOfScope ) ; } ; }
Checks whether a given variable is used from outside of the specified scope.

@param {ASTNode} scopeNode - A scope node to check.
@returns {Function} The predicate function which checks whether a given
variable is used from outside of the specified scope.
Checks whether a given variable is used from outside of the specified scope .