[TypeScript] Fix namespaceless schema generation (#7432)

* Add tests for ts flatc

* fix typescript generation of namespaceless file

* Add typescript genereated code from generate_code.py

* Support multiple module flatc testing

tests/flatc/flatc_ts_tests.py

@@ -0,0 +1,69 @@
+# Copyright 2022 Google Inc. All rights reserved.
+#
+# Licensed under the Apache License, Version 2.0 (the "License");
+# you may not use this file except in compliance with the License.
+# You may obtain a copy of the License at
+#
+#     http://www.apache.org/licenses/LICENSE-2.0
+#
+# Unless required by applicable law or agreed to in writing, software
+# distributed under the License is distributed on an "AS IS" BASIS,
+# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+# See the License for the specific language governing permissions and
+# limitations under the License.
+
+from flatc_test import *
+
+class TsTests():
+
+    def Base(self):
+        # Generate just foo with no extra arguments
+        flatc(["--ts", "foo.fbs"])
+
+        # Should generate the module that exports both foo and its direct
+        # include, bar.
+        assert_file_and_contents(
+            "foo_generated.ts",
+            ["export { Bar } from './bar';", "export { Foo } from './foo';"],
+        )
+
+        # Foo should be generated in place and exports the Foo table.
+        assert_file_and_contents("foo.ts", "export class Foo {")
+
+        # Included files, like bar, should not be generated.
+        assert_file_doesnt_exists("bar.ts")
+
+    def BaseWithNamespace(self):
+        # Generate foo with namespacing, with no extra arguments
+        flatc(["--ts", "foo_with_ns.fbs"])
+
+        # Should generate the module that exports both foo in its namespace
+        # directory and its direct include, bar.
+        assert_file_and_contents(
+            "foo_with_ns_generated.ts",
+            ["export { Bar } from './bar';", "export { Foo } from './something/foo';"],
+        )
+
+        # Foo should be placed in the namespaced directory. It should export
+        # Foo, and the import of Bar should be relative to its location.
+        assert_file_and_contents(
+            "something/foo.ts",
+            ["export class Foo {", "import { Bar } from '../bar';"],
+        )
+
+        # Included files, like bar, should not be generated.
+        assert_file_doesnt_exists("bar.ts")
+
+    def FlatFiles(self):
+        # Generate just foo the flat files option
+        flatc(["--ts", "--ts-flat-files", "foo.fbs"])
+
+        # Should generate a single file that imports bar as a single file, and]
+        # exports the Foo table.
+        assert_file_and_contents(
+            "foo_generated.ts",
+            ["import {Bar as Bar} from './bar_generated';", "export class Foo {"],
+        )
+
+        # The root type Foo should not be generated in its own file.
+        assert_file_doesnt_exists("foo.ts")