Pin default built-in speaker contract

tests/test_release_pins.py

@@ -1,10 +1,24 @@
 import ast
 import hashlib
 from pathlib import Path
+from types import SimpleNamespace
 
 
 ROOT = Path(__file__).resolve().parents[1]
 
+FROZEN_SPEAKER_ANCHORS = {
+    "aaf1a0878e37875382bb0e5c8a3a2ba43be67297": {
+        "speaker_id": "female_voice",
+        "speaker_index": 1,
+        "ui_label": "內建語者 B",
+        "dtype": "float32",
+        "shape": (192,),
+        "sha256": (
+            "e33e4cb6a741d4d1237aa4ff557f1e663d0a6427dccda1f51e83bc149d4188ca"
+        ),
+    }
+}
+
 
 def _string_constants(path: Path) -> dict[str, str]:
     tree = ast.parse(path.read_text(encoding="utf-8"))
@@ -19,6 +33,84 @@ def _string_constants(path: Path) -> dict[str, str]:
     return values
 
 
+def _isolated_load_speakers(*, metadata: dict, speaker_ids: tuple[str, ...]):
+    """Execute only ``_load_speakers`` without importing the GPU application."""
+
+    app_path = ROOT / "app.py"
+    tree = ast.parse(app_path.read_text(encoding="utf-8"))
+    function = next(
+        node
+        for node in tree.body
+        if isinstance(node, ast.FunctionDef) and node.name == "_load_speakers"
+    )
+    module = ast.Module(
+        body=[
+            ast.ImportFrom(
+                module="__future__",
+                names=[ast.alias(name="annotations")],
+                level=0,
+            ),
+            function,
+        ],
+        type_ignores=[],
+    )
+    ast.fix_missing_locations(module)
+
+    load_calls = []
+    centroids = tuple(f"test-centroid-{index}" for index in range(len(speaker_ids)))
+
+    def fake_load(path, **kwargs):
+        load_calls.append((path, kwargs))
+        return {"speaker_ids": speaker_ids, "centroids": centroids}
+
+    namespace = {
+        "MODEL_DIR": "/pinned/model",
+        "METADATA": metadata,
+        "os": SimpleNamespace(
+            path=SimpleNamespace(
+                join=lambda *parts: "/".join(part.strip("/") for part in parts),
+                exists=lambda _path: True,
+            )
+        ),
+        "torch": SimpleNamespace(load=fake_load),
+    }
+    exec(compile(module, app_path, "exec"), namespace)
+    result = namespace["_load_speakers"]()
+    return result, load_calls
+
+
+def test_missing_metadata_speaker_id_selects_frozen_female_voice_as_builtin_b():
+    constants = _string_constants(ROOT / "app.py")
+    contract = FROZEN_SPEAKER_ANCHORS[constants["MODEL_REVISION"]]
+    speaker_ids = ("hung_yi_lee", contract["speaker_id"])
+
+    (labels, default_label), load_calls = _isolated_load_speakers(
+        metadata={},
+        speaker_ids=speaker_ids,
+    )
+
+    assert contract == {
+        "speaker_id": "female_voice",
+        "speaker_index": 1,
+        "ui_label": "內建語者 B",
+        "dtype": "float32",
+        "shape": (192,),
+        "sha256": (
+            "e33e4cb6a741d4d1237aa4ff557f1e663d0a6427dccda1f51e83bc149d4188ca"
+        ),
+    }
+    assert speaker_ids[contract["speaker_index"]] == contract["speaker_id"]
+    assert tuple(labels) == ("內建語者 A", contract["ui_label"])
+    assert labels[contract["ui_label"]] == "test-centroid-1"
+    assert default_label == contract["ui_label"]
+    assert load_calls == [
+        (
+            "pinned/model/checkpoints/speaker_centroids.pt",
+            {"map_location": "cpu", "weights_only": True},
+        )
+    ]
+
+
 def test_remote_model_and_speaker_encoder_are_revision_pinned():
     app_path = ROOT / "app.py"
     source = app_path.read_text(encoding="utf-8")