Fix Blue ROM source setup

tests/build_rom_data_cli_test.py

@@ -0,0 +1,65 @@
+#!/usr/bin/env python3
+"""ROM-free regression tests for source-build version detection and routing."""
+
+from contextlib import redirect_stderr, redirect_stdout
+from io import StringIO
+from pathlib import Path
+from types import SimpleNamespace
+from unittest import TestCase, main, mock
+
+import sys
+
+sys.path.insert(0, str(Path(__file__).resolve().parents[1] / "tools"))
+import build_rom_data  # noqa: E402
+
+
+class BuildRomDataCliTest(TestCase):
+    def run_builder(self, sha1, *extra):
+        manifest = {"romSha1": sha1, "symbols": {}}
+        rom = SimpleNamespace(sha1=sha1)
+        with mock.patch.object(build_rom_data, "RomImage", return_value=rom), \
+                mock.patch.object(build_rom_data, "load_manifest", return_value=manifest), \
+                mock.patch.object(build_rom_data, "build") as build, \
+                mock.patch.object(build_rom_data.os, "makedirs"), \
+                redirect_stdout(StringIO()), redirect_stderr(StringIO()):
+            result = build_rom_data.main([
+                "--rom", "fixture.gb", "--only", "constants", *extra])
+        return result, build
+
+    def test_blue_rom_selects_blue_manifest_and_cache_paths(self):
+        result, build = self.run_builder(
+            build_rom_data.CANONICAL_BLUE_SHA1)
+
+        self.assertEqual(result, 0)
+        args = build.call_args.args
+        self.assertEqual(args[3], "blue/data/generated")
+        self.assertEqual(args[4], "blue/assets/generated")
+
+    def test_red_rom_keeps_historical_root_paths(self):
+        result, build = self.run_builder(build_rom_data.CANONICAL_RED_SHA1)
+
+        self.assertEqual(result, 0)
+        args = build.call_args.args
+        self.assertEqual(args[3], "data/generated")
+        self.assertEqual(args[4], "assets/generated")
+
+    def test_explicit_output_paths_are_preserved(self):
+        result, build = self.run_builder(
+            build_rom_data.CANONICAL_YELLOW_SHA1,
+            "--out", "/tmp/custom-data", "--assets", "/tmp/custom-assets")
+
+        self.assertEqual(result, 0)
+        args = build.call_args.args
+        self.assertEqual(args[3], "/tmp/custom-data")
+        self.assertEqual(args[4], "/tmp/custom-assets")
+
+    def test_unknown_rom_is_rejected_before_build(self):
+        unknown = "0" * 40
+        result, build = self.run_builder(unknown)
+
+        self.assertEqual(result, 1)
+        build.assert_not_called()
+
+
+if __name__ == "__main__":
+    main()