convert_script_files does not require script to exist

src/poetry/core/masonry/builders/builder.py

@@ -352,15 +352,16 @@ def convert_script_files(self) -> list[Path]:
 
                 abs_path = Path.joinpath(self._path, source)
 
-                if not abs_path.exists():
-                    raise RuntimeError(
-                        f"{abs_path} in script specification ({name}) is not found."
-                    )
-
-                if not abs_path.is_file():
-                    raise RuntimeError(
-                        f"{abs_path} in script specification ({name}) is not a file."
-                    )
+                if not self._package.build_script:
+                    # scripts can be generated by build_script, in this case they do not exist here
+                    if not abs_path.exists():
+                        raise RuntimeError(
+                            f"{abs_path} in script specification ({name}) is not found."
+                        )
+                    if not abs_path.is_file():
+                        raise RuntimeError(
+                            f"{abs_path} in script specification ({name}) is not a file."
+                        )
 
                 script_files.append(abs_path)
 

tests/masonry/builders/fixtures/generated_script_file/README.rst

@@ -0,0 +1,2 @@
+Module 1
+========

tests/masonry/builders/fixtures/generated_script_file/build.py

@@ -0,0 +1,14 @@
+from pathlib import Path
+from setuptools.command.build_py import build_py
+
+
+class BuildPyCommand(build_py):
+    def run(self):
+        with open("generated_script_file/generated/script.sh", "w", encoding="utf-8") as f:
+            f.write('#!/usr/bin/env bash\n\necho "Hello World!"\n')
+        ret = super().run()
+        return ret
+
+
+def build(setup_kwargs):
+    setup_kwargs["cmdclass"] = {"build_py": BuildPyCommand}

tests/masonry/builders/fixtures/generated_script_file/pyproject.toml

@@ -0,0 +1,20 @@
+[tool.poetry]
+name = "generated_script_file"
+version = "0.1"
+description = "Some description."
+authors = [
+    "Poetry Maintainers <noreply@python-poetry.org>"
+]
+license = "MIT"
+readme = "README.rst"
+
+[tool.poetry.scripts]
+sh-script = { reference = "generated_script_file/generated/script.sh", type = "file" }
+
+[tool.poetry.build]
+script = "build.py"
+generate-setup-file = true
+
+[build-system]
+requires = ["poetry-core", "setuptools"]
+build-backend = "poetry.core.masonry.api"

tests/masonry/builders/test_wheel.py

@@ -451,3 +451,20 @@ def test_build_py_only_included() -> None:
 
     with zipfile.ZipFile(str(whl)) as z:
         assert "build_with_build_py_only/generated/file.py" in z.namelist()
+
+
+def test_generated_script_file(tmp_path: Path) -> None:
+    """Tests that a file that is generated by build.py can be used as script."""
+    root = fixtures_dir / "generated_script_file"
+    # test only works on a fresh root without already generated script file:
+    tmp_root = tmp_path / "generated_script_file"
+    shutil.copytree(root, tmp_root)
+
+    WheelBuilder.make(Factory().create_poetry(tmp_root))
+
+    whl = next((tmp_root / "dist").glob("generated_script_file-0.1-*.whl"))
+
+    assert whl.exists()
+
+    with zipfile.ZipFile(str(whl)) as z:
+        assert "generated_script_file-0.1.data/scripts/script.sh" in z.namelist()