First implementation of #221

tomschr · tomschr · commit 55d63b016efa · 2020-02-23T15:36:24.000+01:00
* Implement semver.next_version(version, part, *, prerelease_token="rc")
* Add test cases
* Reformat code with black
diff --git a/semver.py b/semver.py
@@ -684,6 +684,48 @@ def finalize_version(version):
     return format_version(verinfo["major"], verinfo["minor"], verinfo["patch"])
 
 
+def next_version(version, part, *, prerelease_token="rc"):
+    """
+    Determines the next version, takeing prepreleases into account.
+
+    The "major", "minor", and "patch" raises the respective parts like
+    the ``bump_*`` functions. The real difference is using the
+    "preprelease" part. It gives you the next patch version of the prerelease,
+    for example:
+
+    >>> semver.next_version("0.1.4", "prerelease")
+    '0.1.5-rc.1'
+
+    :param version: a semver version string
+    :param part: One of "major", "minor", "patch", or "prerelease"
+    :param prerelease_token: prefix string of prerelease, defaults to 'rc'
+    :return:
+    """
+    validparts = {
+        "major",
+        "minor",
+        "patch",
+        "prerelease",
+        # "build", # ???
+    }
+    if part not in validparts:
+        raise ValueError(
+            "Invalid part. " f"Expected one of {validparts}, but got {part!r}"
+        )
+    version = VersionInfo.parse(version)
+    if part == "major":
+        return str(version.bump_major())
+    elif part == "minor":
+        return str(version.bump_minor())
+    elif part == "patch":
+        return str(version.bump_patch())
+    elif part == "prerelease":
+        return str(version.bump_patch().bump_prerelease(token=prerelease_token))
+
+    raise RuntimeError(f"Should not happen, got {part}")
+
+
+# ---- CLI
 def cmd_bump(args):
     """
     Subcommand: Bumps a version.
diff --git a/test_semver.py b/test_semver.py
@@ -20,6 +20,7 @@
     match,
     max_ver,
     min_ver,
+    next_version,
     parse,
     parse_version_info,
     process,
@@ -39,6 +40,7 @@
     match,
     max_ver,
     min_ver,
+    next_version,
     parse,
     process,
     replace,
@@ -827,3 +829,16 @@ def test_replace_raises_ValueError_for_non_numeric_values():
 def test_should_versioninfo_isvalid():
     assert VersionInfo.isvalid("1.0.0") is True
     assert VersionInfo.isvalid("foo") is False
+
+
+@pytest.mark.parametrize(
+    "version, part, expected",
+    [
+        ("1.2.3", "major", "2.0.0"),
+        ("1.3.1", "minor", "1.4.0"),
+        ("1.3.2", "patch", "1.3.3"),
+        ("0.1.4", "prerelease", "0.1.5-rc.1"),
+    ],
+)
+def test_next_version(version, part, expected):
+    assert next_version(version, part) == expected
