add sheet music OCR CLI tool using Audiveris

Adds a Typer CLI (sheet-music-ocr) that converts scanned sheet music
(PDF, PNG, JPG, TIFF) to MusicXML via Audiveris, preserving lyrics and
text annotations. Includes Audiveris in the nix dev shell.

https://claude.ai/code/session_017GqUbuRDT58toRaxMtfRmf

tests/test_sheet_music_ocr.py

@@ -0,0 +1,154 @@
+import zipfile
+from unittest.mock import patch
+
+import pytest
+from typer.testing import CliRunner
+
+from python.sheet_music_ocr.audiveris import AudiverisError, find_audiveris, run_audiveris
+from python.sheet_music_ocr.main import SUPPORTED_EXTENSIONS, app, extract_mxml_from_mxl
+
+runner = CliRunner()
+
+
+def make_mxl(path, xml_content=b"<score-partwise/>"):
+    """Create a minimal .mxl (ZIP) file with a MusicXML inside."""
+    with zipfile.ZipFile(path, "w") as zf:
+        zf.writestr("score.xml", xml_content)
+
+
+class TestExtractMxmlFromMxl:
+    def test_extracts_xml(self, tmp_path):
+        mxl = tmp_path / "test.mxl"
+        output = tmp_path / "output.mxml"
+        content = b"<score-partwise>hello</score-partwise>"
+        make_mxl(mxl, content)
+
+        result = extract_mxml_from_mxl(mxl, output)
+
+        assert result == output
+        assert output.read_bytes() == content
+
+    def test_skips_meta_inf(self, tmp_path):
+        mxl = tmp_path / "test.mxl"
+        output = tmp_path / "output.mxml"
+        with zipfile.ZipFile(mxl, "w") as zf:
+            zf.writestr("META-INF/container.xml", "<container/>")
+            zf.writestr("score.xml", b"<score/>")
+
+        extract_mxml_from_mxl(mxl, output)
+
+        assert output.read_bytes() == b"<score/>"
+
+    def test_raises_when_no_xml(self, tmp_path):
+        mxl = tmp_path / "test.mxl"
+        output = tmp_path / "output.mxml"
+        with zipfile.ZipFile(mxl, "w") as zf:
+            zf.writestr("readme.txt", "no xml here")
+
+        with pytest.raises(FileNotFoundError, match="No MusicXML"):
+            extract_mxml_from_mxl(mxl, output)
+
+
+class TestFindAudiveris:
+    def test_raises_when_not_found(self):
+        with (
+            patch("python.sheet_music_ocr.audiveris.shutil.which", return_value=None),
+            pytest.raises(AudiverisError, match="not found"),
+        ):
+            find_audiveris()
+
+    def test_returns_path_when_found(self):
+        with patch("python.sheet_music_ocr.audiveris.shutil.which", return_value="/usr/bin/audiveris"):
+            assert find_audiveris() == "/usr/bin/audiveris"
+
+
+class TestRunAudiveris:
+    def test_raises_on_nonzero_exit(self, tmp_path):
+        with (
+            patch("python.sheet_music_ocr.audiveris.find_audiveris", return_value="audiveris"),
+            patch("python.sheet_music_ocr.audiveris.subprocess.run") as mock_run,
+        ):
+            mock_run.return_value.returncode = 1
+            mock_run.return_value.stderr = "something went wrong"
+
+            with pytest.raises(AudiverisError, match="failed"):
+                run_audiveris(tmp_path / "input.pdf", tmp_path / "output")
+
+    def test_raises_when_no_mxl_produced(self, tmp_path):
+        output_dir = tmp_path / "output"
+        output_dir.mkdir()
+
+        with (
+            patch("python.sheet_music_ocr.audiveris.find_audiveris", return_value="audiveris"),
+            patch("python.sheet_music_ocr.audiveris.subprocess.run") as mock_run,
+        ):
+            mock_run.return_value.returncode = 0
+
+            with pytest.raises(AudiverisError, match=r"no \.mxl output"):
+                run_audiveris(tmp_path / "input.pdf", output_dir)
+
+    def test_returns_mxl_path(self, tmp_path):
+        output_dir = tmp_path / "output"
+        output_dir.mkdir()
+        mxl = output_dir / "score.mxl"
+        make_mxl(mxl)
+
+        with (
+            patch("python.sheet_music_ocr.audiveris.find_audiveris", return_value="audiveris"),
+            patch("python.sheet_music_ocr.audiveris.subprocess.run") as mock_run,
+        ):
+            mock_run.return_value.returncode = 0
+
+            result = run_audiveris(tmp_path / "input.pdf", output_dir)
+            assert result == mxl
+
+
+class TestCli:
+    def test_missing_input_file(self, tmp_path):
+        result = runner.invoke(app, [str(tmp_path / "nonexistent.pdf")])
+        assert result.exit_code == 1
+        assert "does not exist" in result.output
+
+    def test_unsupported_format(self, tmp_path):
+        bad_file = tmp_path / "music.bmp"
+        bad_file.touch()
+        result = runner.invoke(app, [str(bad_file)])
+        assert result.exit_code == 1
+        assert "Unsupported format" in result.output
+
+    def test_supported_extensions_complete(self):
+        assert ".pdf" in SUPPORTED_EXTENSIONS
+        assert ".png" in SUPPORTED_EXTENSIONS
+        assert ".jpg" in SUPPORTED_EXTENSIONS
+        assert ".jpeg" in SUPPORTED_EXTENSIONS
+        assert ".tiff" in SUPPORTED_EXTENSIONS
+
+    def test_successful_conversion(self, tmp_path):
+        input_file = tmp_path / "score.pdf"
+        input_file.touch()
+        output_file = tmp_path / "score.mxml"
+
+        mxl_path = tmp_path / "tmp_mxl" / "score.mxl"
+        mxl_path.parent.mkdir()
+        make_mxl(mxl_path, b"<score-partwise/>")
+
+        with patch("python.sheet_music_ocr.main.run_audiveris", return_value=mxl_path):
+            result = runner.invoke(app, [str(input_file), "-o", str(output_file)])
+
+        assert result.exit_code == 0
+        assert output_file.exists()
+        assert "Written" in result.output
+
+    def test_default_output_path(self, tmp_path):
+        input_file = tmp_path / "score.png"
+        input_file.touch()
+
+        mxl_path = tmp_path / "tmp_mxl" / "score.mxl"
+        mxl_path.parent.mkdir()
+        make_mxl(mxl_path)
+
+        with patch("python.sheet_music_ocr.main.run_audiveris", return_value=mxl_path):
+            result = runner.invoke(app, [str(input_file)])
+
+        assert result.exit_code == 0
+        assert (tmp_path / "score.mxml").exists()