feat: create a new ScalarLeafsRuleWithoutSuggestions validator rule

ScalarLeafsRule also appends "Did you mean" schema suggestions like
e.g., KnownTypeNamesRule, but wasn't treated previously like other
validator rules, possibly because it was calling `Suggestf()` which adds
the "Did you mean" string.

Author: XuankangLin

validator/rules/scalar_leafs.go

@@ -6,31 +6,31 @@ import (
 	. "github.com/vektah/gqlparser/v2/validator/core"
 )
 
-var ScalarLeafsRule = Rule{
-	Name: "ScalarLeafs",
-	RuleFunc: func(observers *Events, addError AddErrFunc) {
-		observers.OnField(func(walker *Walker, field *ast.Field) {
-			if field.Definition == nil {
-				return
-			}
+func ruleFuncScalarLeafs(observers *Events, addError AddErrFunc, disableSuggestion bool) {
+	observers.OnField(func(walker *Walker, field *ast.Field) {
+		if field.Definition == nil {
+			return
+		}
 
-			fieldType := walker.Schema.Types[field.Definition.Type.Name()]
-			if fieldType == nil {
-				return
-			}
+		fieldType := walker.Schema.Types[field.Definition.Type.Name()]
+		if fieldType == nil {
+			return
+		}
 
-			if fieldType.IsLeafType() && len(field.SelectionSet) > 0 {
+		if fieldType.IsLeafType() && len(field.SelectionSet) > 0 {
+			addError(
+				Message(`Field "%s" must not have a selection since type "%s" has no subfields.`, field.Name, fieldType.Name),
+				At(field.Position),
+			)
+		}
+
+		if !fieldType.IsLeafType() && len(field.SelectionSet) == 0 {
+			if disableSuggestion {
 				addError(
-					Message(
-						`Field "%s" must not have a selection since type "%s" has no subfields.`,
-						field.Name,
-						fieldType.Name,
-					),
+					Message(`Field "%s" of type "%s" must have a selection of subfields.`, field.Name, field.Definition.Type.String()),
 					At(field.Position),
 				)
-			}
-
-			if !fieldType.IsLeafType() && len(field.SelectionSet) == 0 {
+			} else {
 				addError(
 					Message(
 						`Field "%s" of type "%s" must have a selection of subfields.`,
@@ -41,6 +41,20 @@ var ScalarLeafsRule = Rule{
 					At(field.Position),
 				)
 			}
-		})
+		}
+	})
+}
+
+var ScalarLeafsRule = Rule{
+	Name: "ScalarLeafs",
+	RuleFunc: func(observers *Events, addError AddErrFunc) {
+		ruleFuncScalarLeafs(observers, addError, false)
+	},
+}
+
+var ScalarLeafsRuleWithoutSuggestions = Rule{
+	Name: "ScalarLeafsWithoutSuggestions",
+	RuleFunc: func(observers *Events, addError AddErrFunc) {
+		ruleFuncScalarLeafs(observers, addError, true)
 	},
 }