1package validator
 2
 3import (
 4	"github.com/vektah/gqlparser/ast"
 5	. "github.com/vektah/gqlparser/validator"
 6)
 7
 8func init() {
 9	AddRule("NoUnusedVariables", func(observers *Events, addError AddErrFunc) {
10		observers.OnOperation(func(walker *Walker, operation *ast.OperationDefinition) {
11			for _, varDef := range operation.VariableDefinitions {
12				if varDef.Used {
13					continue
14				}
15
16				if operation.Name != "" {
17					addError(
18						Message(`Variable "$%s" is never used in operation "%s".`, varDef.Variable, operation.Name),
19						At(varDef.Position),
20					)
21				} else {
22					addError(
23						Message(`Variable "$%s" is never used.`, varDef.Variable),
24						At(varDef.Position),
25					)
26				}
27			}
28		})
29	})
30}