crate: improve determining project name/version from directory name

If the heuristics fail because the project uses a weird naming or
versioning scheme or if the directory name does not match the
"{project}-{version}" pattern. This is mostly the case for "workspace"
proejcts.

In the case the heuristics fail, the version can be overriden on the
command line.

rust2rpm/__main__.py

@@ -8,7 +8,7 @@ from cargo2rpm.semver import Version
 from rust2rpm import log
 from rust2rpm.cli import get_parser
 from rust2rpm.conf import load_config
-from rust2rpm.crate import InvalidProjectError, process_project
+from rust2rpm.crate import InvalidProjectError, InvalidVersionError, process_project
 from rust2rpm.cratesio import NoVersionsError
 from rust2rpm.distgit import get_package_info
 from rust2rpm.generator import spec_render_crate, spec_render_project, spec_render_workspace
@@ -56,6 +56,12 @@ def main():
     except InvalidProjectError:
         log.error(f"Invalid argument: {args.crate!r} is not a local file or directory")
         sys.exit(1)
+    except InvalidVersionError:
+        log.error(
+            f"Could not determine project name and version automatically. "
+            "Please specify the project version on the command line."
+        )
+        sys.exit(1)
 
     if metadata.is_workspace():
         base_name = project

rust2rpm/crate.py

@@ -58,6 +58,10 @@ class InvalidProjectError(ValueError):
     pass
 
 
+class InvalidVersionError(ValueError):
+    pass
+
+
 def local_toml_file(toml_path: str) -> tuple[str, list[str], list[str]]:
     assert os.path.isfile(toml_path)
     assert os.path.basename(toml_path) == "Cargo.toml"
@@ -149,14 +153,52 @@ def project_is_path(path: str) -> bool:
     return "/" in path or path in {".", ".."}
 
 
-def guess_local_project_version_from_path(project: str) -> tuple[str, str]:
+def guess_local_project_version_from_dir(dir_name: str) -> tuple[str, str]:
+    """
+    Use a simple heuristic to determine the project name and version from the
+    name of the directory that contains the Cargo.toml file.
+
+    Raises an InvalidVersionError if the automatically determined version is
+    not valid according to SemVer.
+    """
+
+    project = dir_name.rstrip("0123456789.").removesuffix("-")
+    version = dir_name.removeprefix(f"{project}-")
+
+    try:
+        Version.parse(version)
+    except ValueError as exc:
+        raise InvalidVersionError(exc.args)
+
+    return project, version
+
+
+def guess_local_project_version_from_path(project: str, version: Optional[str]) -> tuple[str, str]:
+    """
+    Use a simple heuristic to determine the project name and version from the
+    "project" argument supplied on the command line.
+
+    If the argument points at a file (i.e. a Cargo.toml file), the heuristics
+    use the name of the file's parent directory. If the argument points at a
+    directory, the name of the directory itself is used.
+
+    Raises an InvalidVersionError if the heuristics for automatically
+    determining the project name and version fail, or if the automatically
+    determined version is not valid according to SemVer. In this case,
+    supplying the optional "version" argument on the command line can override
+    the version string.
+    """
+
     if os.path.isdir(project):
         dir_name = os.path.split(os.path.abspath(project))[1]
     else:
         dir_name = os.path.split(os.path.dirname(os.path.abspath(project)))[1]
-    project = dir_name.rstrip("0123456789.").removesuffix("-")
-    version = dir_name.removeprefix(f"{project}-")
-    return project, version
+
+    if version:
+        project = dir_name.removesuffix(f"-{version}")
+        return project, version
+    else:
+        return guess_local_project_version_from_dir(dir_name)
 
 
 @contextlib.contextmanager
@@ -170,6 +212,7 @@ def toml_temp_copy(toml_path: str):
 
 def process_project_local(
     project: str,
+    version: Optional[str],
     patch: bool,
     patch_foreign: bool,
     vendor: bool,
@@ -188,7 +231,7 @@ def process_project_local(
 
         # fall back to the directory name for determining the name / version
         # of the project heuristically
-        name, version = guess_local_project_version_from_path(project)
+        name, version = guess_local_project_version_from_path(project, version)
 
         log.warn(f"Falling back to {name!r} as the name of the project (based on the name of the containing folder).")
         diffs: tuple[Optional[list[str]], Optional[list[str]]] = (None, None)
@@ -276,7 +319,7 @@ def process_project(
                 log.warn("The '--store-crate' flag has no effect for unpacked sources.")
 
             name, version, diffs, metadata, doc_files, license_files, vendor_tarball = process_project_local(
-                project, patch, patch_foreign, vendor
+                project, version, patch, patch_foreign, vendor
             )
             return name, version, diffs, metadata, doc_files, license_files, True, vendor_tarball
 

rust2rpm/generator.py

@@ -533,7 +533,12 @@ def spec_render_workspace(
 
     is_cdylib = metadata.is_cdylib()
 
-    rpm_version = Version.parse(upstream_version).to_rpm()
+    try:
+        rpm_version = Version.parse(upstream_version).to_rpm()
+    except ValueError:
+        log.warn(f"Version {upstream_version!r} is not valid according to SemVer.")
+        rpm_version = upstream_version
+
     rpm_description = main_package.get_description()
     rpm_summary = main_package.get_summary()
 

rust2rpm/tests/test_crate.py

@@ -0,0 +1,29 @@
+import pytest
+
+from rust2rpm.crate import guess_local_project_version_from_dir
+
+
+@pytest.mark.parametrize(
+    "path,project,version",
+    [
+        ("project-1.2.3", "project", "1.2.3"),
+        ("test-project-1.2.3", "test-project", "1.2.3"),
+    ],
+    ids=repr,
+)
+def test_guess_local_project_version_from_dir(path: str, project: str, version: str):
+    p, v = guess_local_project_version_from_dir(path)
+    assert (p, v) == (project, version)
+
+
+@pytest.mark.parametrize(
+    "path,error",
+    [
+        ("helix-23.10-source", "Invalid version"),
+    ],
+    ids=repr,
+)
+def test_guess_local_project_version_from_dir_fail(path: str, error: str):
+    with pytest.raises(ValueError) as exc:
+        guess_local_project_version_from_dir(path)
+    assert error in str(exc.value)