[BuildLibrary] fix auto-rename during merge

masque/test/test_build_library.py

@@ -1,19 +1,47 @@
+from collections.abc import Iterator
+
 import pytest
 
 from ..builder import Pather
 from ..error import BuildError
-from ..library import BuildLibrary, Library, cell
+from ..library import BuildLibrary, BuildReport, ILibraryView, Library, cell, dangling_mode_t
 from ..pattern import Pattern
 from ..ports import Port
 
 
-def _owned_by(report, owner: str) -> set[str]:
+def _owned_by(report: BuildReport, owner: str) -> set[str]:
     return {
         name for name, prov in report.provenance.items()
         if prov.owner_declared_name == owner
     }
 
 
+class _MetadataSource(ILibraryView):
+    def __init__(self, mapping: dict[str, Pattern], child_graph: dict[str, set[str]]) -> None:
+        self.mapping = mapping
+        self._child_graph = child_graph
+        self.loads = 0
+
+    def __getitem__(self, key: str) -> Pattern:
+        self.loads += 1
+        return self.mapping[key]
+
+    def __iter__(self) -> Iterator[str]:
+        return iter(self.mapping)
+
+    def __len__(self) -> int:
+        return len(self.mapping)
+
+    def __contains__(self, key: object) -> bool:
+        return key in self.mapping
+
+    def source_order(self) -> tuple[str, ...]:
+        return tuple(self.mapping)
+
+    def child_graph(self, dangling: dangling_mode_t = 'error') -> dict[str, set[str]]:     # noqa: ARG002
+        return self._child_graph
+
+
 def test_build_library_traces_declared_dependencies_out_of_order() -> None:
     builder = BuildLibrary()
 
@@ -59,6 +87,36 @@ def test_build_library_tracks_helper_provenance_and_tree_merge_renames() -> None
     assert any(name != prov.requested_name for name, prov in helpers)
 
 
+def test_build_library_authoring_tree_merge_renames_repeated_single_use_names() -> None:
+    builder = BuildLibrary()
+    tree = Library({"_helper": Pattern()})
+
+    name_a = builder << tree
+    name_b = builder << tree
+    built, report = builder.build()
+
+    assert name_a == "_helper"
+    assert name_b != "_helper"
+    assert name_a in built
+    assert name_b in built
+    assert report.provenance[name_b].requested_name == name_b
+
+
+def test_build_library_authoring_tree_merge_remaps_internal_refs() -> None:
+    builder = BuildLibrary()
+    builder["_helper"] = Pattern()
+    helper = Pattern()
+    top = Pattern()
+    top.ref("_helper")
+
+    top_name = builder << Library({"_helper": helper, "top": top})
+    built, _report = builder.build()
+
+    assert top_name == "top"
+    assert "_helper" not in built[top_name].refs
+    assert any(name != "_helper" for name in built[top_name].refs)
+
+
 def test_build_library_requires_build_session_for_reads_and_freezes_after_build() -> None:
     builder = BuildLibrary()
     builder["leaf"] = Pattern()
@@ -206,6 +264,70 @@ def test_build_library_add_source_can_rename_every_source_cell() -> None:
     assert report.provenance["mapped_child"].requested_name == "child"
 
 
+def test_build_library_authoring_tree_merge_keeps_source_view_lazy() -> None:
+    child = Pattern()
+    top = Pattern()
+    top.ref("child")
+    source = _MetadataSource(
+        {"child": child, "top": top},
+        {"child": set(), "top": {"child"}},
+    )
+
+    builder = BuildLibrary()
+    top_name = builder << source
+    built, _report = builder.build()
+
+    assert top_name == "top"
+    assert "top" in built
+    assert source.loads == 0
+
+
+def test_build_library_authoring_source_tree_merge_returns_renamed_top() -> None:
+    existing = Pattern()
+    source_top = Pattern()
+    source = _MetadataSource(
+        {"_helper": source_top},
+        {"_helper": set()},
+    )
+
+    builder = BuildLibrary()
+    builder["_helper"] = existing
+    top_name = builder << source
+    built, _report = builder.build()
+
+    assert top_name != "_helper"
+    assert top_name in built
+    assert source.loads == 0
+
+
+def test_build_library_authoring_source_tree_merge_remaps_renamed_child_on_materialization() -> None:
+    source_helper = Pattern()
+    source_top = Pattern()
+    source_top.ref("_helper")
+    source = _MetadataSource(
+        {"_helper": source_helper, "top": source_top},
+        {"_helper": set(), "top": {"_helper"}},
+    )
+
+    builder = BuildLibrary()
+    builder["_helper"] = Pattern()
+    top_name = builder << source
+    built, _report = builder.build(output="library")
+
+    assert top_name == "top"
+    assert "_helper" not in built[top_name].refs
+    assert source.loads == 2
+
+
+def test_build_library_rejects_authoring_tree_le_before_mutating() -> None:
+    builder = BuildLibrary()
+
+    with pytest.raises(BuildError, match="__le__"):
+        _abstract = builder <= Library({"leaf": Pattern()})
+
+    assert list(builder) == []
+
+
 def test_build_library_rejects_source_cells_added_after_add_source() -> None:
     source = Library({"src": Pattern()})
     builder = BuildLibrary()