feat: Adds buildASTSchema

Author: NeedleInAJayStack

Sources/GraphQL/Utilities/BuildASTSchema.swift

@@ -0,0 +1,85 @@
+/**
+ * This takes the ast of a schema document produced by the parse function in
+ * src/language/parser.js.
+ *
+ * If no schema definition is provided, then it will look for types named Query,
+ * Mutation and Subscription.
+ *
+ * Given that AST it constructs a GraphQLSchema. The resulting schema
+ * has no resolve methods, so execution will use default resolvers.
+ */
+public func buildASTSchema(
+    documentAST: Document,
+    assumeValid: Bool = false,
+    assumeValidSDL: Bool = false
+) throws -> GraphQLSchema {
+    if assumeValid != true, !assumeValidSDL {
+        try assertValidSDL(documentAST: documentAST)
+    }
+    let emptySchemaConfig = GraphQLSchemaNormalizedConfig()
+    let config = try extendSchemaImpl(emptySchemaConfig, documentAST)
+
+    if config.astNode == nil {
+        try config.types.forEach { type in
+            switch type.name {
+            case "Query": config.query = try checkOperationType(operationType: .query, type: type)
+            case "Mutation": config
+                .mutation = try checkOperationType(operationType: .mutation, type: type)
+            case "Subscription": config
+                .subscription = try checkOperationType(operationType: .subscription, type: type)
+            default: break
+            }
+        }
+    }
+
+    var directives = config.directives
+    directives.append(contentsOf: specifiedDirectives.filter { stdDirective in
+        config.directives.allSatisfy { directive in
+            directive.name != stdDirective.name
+        }
+    })
+
+    config.directives = directives
+
+    return try GraphQLSchema(config: config)
+}
+
+/**
+ * A helper function to build a GraphQLSchema directly from a source
+ * document.
+ */
+public func buildSchema(
+    source: Source,
+    assumeValid: Bool = false,
+    assumeValidSDL: Bool = false
+) throws -> GraphQLSchema {
+    let document = try parse(
+        source: source
+    )
+
+    return try buildASTSchema(
+        documentAST: document,
+        assumeValid: assumeValid,
+        assumeValidSDL: assumeValidSDL
+    )
+}
+
+/**
+ * A helper function to build a GraphQLSchema directly from a source
+ * document.
+ */
+public func buildSchema(
+    source: String,
+    assumeValid: Bool = false,
+    assumeValidSDL: Bool = false
+) throws -> GraphQLSchema {
+    let document = try parse(
+        source: source
+    )
+
+    return try buildASTSchema(
+        documentAST: document,
+        assumeValid: assumeValid,
+        assumeValidSDL: assumeValidSDL
+    )
+}