Making import of schema module in test mock files @testable (#697)

Author: BobaFetters

Tests/ApolloCodegenTests/CodeGeneration/Templates/TemplateRenderer_TestMockFile_Tests.swift

@@ -119,7 +119,7 @@ class TemplateRenderer_TestMockFile_Tests: XCTestCase {
     for test in tests {
       let expected = """
       import ApolloTestSupport
-      import \(test.importModuleName)
+      @testable import \(test.importModuleName)
 
       """
       let config = buildConfig(moduleType: test.schemaTypes, operations: test.operations)
@@ -137,7 +137,7 @@ class TemplateRenderer_TestMockFile_Tests: XCTestCase {
     // given
     let expected = """
     import ApolloTestSupport
-    import TestSchema
+    @testable import TestSchema
 
     """
     let config = buildConfig(

apollo-ios-codegen/Sources/ApolloCodegenLib/Templates/TemplateRenderer.swift

@@ -355,7 +355,7 @@ struct ImportStatementTemplate {
     static func template(for config: ApolloCodegen.ConfigurationContext) -> TemplateString {
       return """
       import ApolloTestSupport
-      import \(config.schemaModuleName)
+      @testable import \(config.schemaModuleName)
       """
     }
   }