[Fusion] Aligned "IsInvalidSyntaxRule" with the specification (#8777)

Author: glen-84

src/HotChocolate/Fusion-vnext/src/Fusion.Composition/SourceSchemaValidationRules/IsInvalidSyntaxRule.cs

@@ -6,8 +6,8 @@ namespace HotChocolate.Fusion.SourceSchemaValidationRules;
 
 /// <summary>
 /// The <c>@is</c> directive’s <c>field</c> argument must be syntactically valid GraphQL. If
-/// the selection map string is malformed (e.g., missing closing braces, unbalanced quotes, invalid
-/// tokens), then the schema cannot be composed correctly. In such cases, the error
+/// the <c>FieldSelectionMap</c> string is malformed (e.g., missing closing braces, unbalanced
+/// quotes, invalid tokens), then the schema cannot be composed correctly. In such cases, the error
 /// <c>IS_INVALID_SYNTAX</c> is raised.
 /// </summary>
 /// <seealso href="https://graphql.github.io/composite-schemas-spec/draft/#sec-Is-Invalid-Syntax">

src/HotChocolate/Fusion-vnext/test/Fusion.Composition.Tests/SourceSchemaValidationRules/IsInvalidSyntaxRuleTests.cs

@@ -48,16 +48,16 @@ public static TheoryData<string[]> ValidExamplesData()
     {
         return new TheoryData<string[]>
         {
-            // In the following example, the @is directive’s "field" argument is a valid selection
-            // map and satisfies the rule.
+            // In the following example, the @is directive’s "field" argument is a valid
+            // FieldSelectionMap and satisfies the rule.
             {
                 [
                     """
                     type Query {
-                        personById(id: ID! @is(field: "id")): Person @lookup
+                        product(id: ID! @is(field: "id")): Product @lookup
                     }
 
-                    type Person {
+                    type Product {
                         id: ID!
                         name: String
                     }
@@ -77,18 +77,18 @@ public static TheoryData<string[], string[]> InvalidExamplesData()
                 [
                     """
                     type Query {
-                        personById(id: ID! @is(field: "{ id ")): Person @lookup
+                        product(id: ID! @is(field: "{ id ")): Product @lookup
                     }
 
-                    type Person {
+                    type Product {
                         id: ID!
                         name: String
                     }
                     """
                 ],
                 [
-                    "The @is directive on argument 'Query.personById(id:)' in schema 'A' "
-                    + "contains invalid syntax in the 'field' argument."
+                    "The @is directive on argument 'Query.product(id:)' in schema 'A' contains "
+                    + "invalid syntax in the 'field' argument."
                 ]
             }
         };