fix(GraphQL): This PR extend int64 range to 64-bit numeric values and adds input coercing and validation for integers.

graphql/e2e/common/error_test.yaml

@@ -100,3 +100,22 @@
     [ { "message": "Cannot query field \"getAuthor\" on type \"Subscription\".",
         "locations": [ { "line": 2, "column": 3 } ] } ]
 
+-
+  name: "Out of range error for int type"
+  gqlrequest: |
+    mutation {
+      addPost(input:[{title:"Dgraph",author:{name:"Bob"},numLikes:2147483648}]){
+        post{
+          title
+          numLikes
+          author{
+            name
+          }
+        }
+      }
+    }
+  gqlvariables:
+    { }
+  errors:
+    [ { "message": "Out of range value '2147483648', for Variable type `Int`",
+        "locations": [ { "line": 2, "column": 63 } ] } ]

graphql/schema/rules.go

@@ -45,6 +45,7 @@ func init() {
 
 	validator.AddRule("Check variable type is correct", variableTypeCheck)
 	validator.AddRule("Check for list type value", listTypeCheck)
+	validator.AddRule("Check range for Int type", intRangeCheck)
 
 }
 

graphql/schema/validation_rules.go

@@ -19,6 +19,8 @@ package schema
 import (
 	"github.com/vektah/gqlparser/v2/ast"
 	"github.com/vektah/gqlparser/v2/validator"
+	"math"
+	"strconv"
 )
 
 func listTypeCheck(observers *validator.Events, addError validator.AddErrFunc) {
@@ -63,3 +65,27 @@ func variableTypeCheck(observers *validator.Events, addError validator.AddErrFun
 			value.ExpectedType.String()), validator.At(value.Position))
 	})
 }
+
+func intRangeCheck(observers *validator.Events, addError validator.AddErrFunc) {
+	observers.OnValue(func(walker *validator.Walker, value *ast.Value) {
+		if value.Definition == nil || value.ExpectedType == nil {
+			return
+		}
+
+		if value.Kind != ast.IntValue || value.Definition.Name != "Int" {
+			return
+		}
+
+		intVal, err := strconv.ParseInt(value.Raw, 10, 64)
+		if err != nil {
+			addError(validator.Message("%s", err))
+			return
+		}
+		if intVal <= math.MaxInt32 && intVal >= math.MinInt32 {
+			return
+		}
+
+		addError(validator.Message("Out of range value '%s', for Variable type `%s`",
+			value.Raw, value.Definition.Name), validator.At(value.Position))
+	})
+}