Function getFieldReference

packages/language/src/utils.ts:435–443

(expr: Expression)

 * Gets the data field referenced by the given expression, if any. Returns `undefined` if the expression is not a reference to a data field.
 */
export function getFieldReference(expr: Expression): DataField | undefined {
    if (isReferenceExpr(expr) && isDataField(expr.target.ref)) {
        return expr.target.ref;
    } else if (isMemberAccessExpr(expr) && isDataField(expr.member.ref)) {
        return expr.member.ref;
    } else {
        return undefined;
    }
}

// TODO: move to policy plugin
export function isCheckInvocation(node: AstNode) {