support for repeatable on directives

Author: samisuteria

Sources/GraphQL/Language/AST.swift

@@ -1684,19 +1684,22 @@ public final class DirectiveDefinition {
     public let name: Name
     public let arguments: [InputValueDefinition]
     public let locations: [Name]
+    public let repeatable: Bool
 
     init(
         loc: Location? = nil,
         description: StringValue? = nil,
         name: Name,
         arguments: [InputValueDefinition] = [],
-        locations: [Name]
+        locations: [Name],
+        repeatable: Bool = false
     ) {
         self.loc = loc
         self.name = name
         self.description = description
         self.arguments = arguments
         self.locations = locations
+        self.repeatable = repeatable
     }
 }
 

Sources/GraphQL/Language/Parser.swift

@@ -1190,7 +1190,7 @@ func parseInputObjectExtensionDefinition(lexer: Lexer) throws -> InputObjectExte
 
 /**
  * DirectiveDefinition :
- *   - directive @ Name ArgumentsDefinition? on DirectiveLocations
+ *   - directive @ Name ArgumentsDefinition? repeatable? on DirectiveLocations
  */
 func parseDirectiveDefinition(lexer: Lexer) throws -> DirectiveDefinition {
     let start = lexer.token
@@ -1199,15 +1199,30 @@ func parseDirectiveDefinition(lexer: Lexer) throws -> DirectiveDefinition {
     try expect(lexer: lexer, kind: .at)
     let name = try parseName(lexer: lexer)
     let args = try parseArgumentDefs(lexer: lexer)
-    try expectKeyword(lexer: lexer, value: "on")
-    let locations = try parseDirectiveLocations(lexer: lexer)
-    return DirectiveDefinition(
-        loc: loc(lexer: lexer, startToken: start),
-        description: description,
-        name: name,
-        arguments: args,
-        locations: locations
-    )
+
+    do {
+        try expectKeyword(lexer: lexer, value: "repeatable")
+        try expectKeyword(lexer: lexer, value: "on")
+        let locations = try parseDirectiveLocations(lexer: lexer)
+        return DirectiveDefinition(
+            loc: loc(lexer: lexer, startToken: start),
+            description: description,
+            name: name,
+            arguments: args,
+            locations: locations,
+            repeatable: true
+        )
+    } catch {
+        try expectKeyword(lexer: lexer, value: "on")
+        let locations = try parseDirectiveLocations(lexer: lexer)
+        return DirectiveDefinition(
+            loc: loc(lexer: lexer, startToken: start),
+            description: description,
+            name: name,
+            arguments: args,
+            locations: locations
+        )
+    }
 }
 
 /**