Implement of VersionInfo.next_version() function

tomschr · gsakkis · ppkt · tomschr · commit c0a1f146ed49 · 2020-04-27T20:03:28.000+02:00
Synopsis: semver.VersionInfo.next_version(version, part, prerelease_token="rc")

* Add test cases
  * test_next_version
  * test_next_version_with_invalid_parts
* Reformat code with black
* Document it in usage.rst
* Implement "nextver" subcommand for pysemver command

Co-authored-by: George Sakkis &lt;gsakkis@users.noreply.github.com&gt;
Co-authored-By: Karol &lt;ppkt@users.noreply.github.com&gt;
diff --git a/docs/usage.rst b/docs/usage.rst
@@ -244,8 +244,8 @@ It is possible to convert a :class:`semver.VersionInfo` instance:
     (5, 4, 2, None, None)
 
 
-Increasing Parts of a Version
------------------------------
+Raising Parts of a Version
+--------------------------
 
 The ``semver`` module contains the following functions to raise parts of
 a version:
@@ -276,6 +276,30 @@ a version:
 Likewise the module level functions :func:`semver.bump_major`.
 
 
+Increasing Parts of a Version Taking into Account Prereleases
+-------------------------------------------------------------
+
+.. versionadded:: 2.10.0
+   Added :func:`semver.VersionInfo.next_version`.
+
+If you want to raise your version and take prereleases into account,
+the function :func:`semver.VersionInfo.next_version` would perhaps a
+better fit.
+
+
+.. code-block:: python
+
+    >>> v = semver.VersionInfo.parse("3.4.5-pre.2+build.4")
+    >>> str(v.next_version(part="prerelease"))
+    '3.4.5-pre.3'
+    >>> str(semver.VersionInfo.parse("3.4.5-pre.2+build.4").next_version(part="patch"))
+    '3.4.5'
+    >>> str(semver.VersionInfo.parse("3.4.5+build.4").next_version(part="patch"))
+    '3.4.5'
+    >>> str(semver.VersionInfo.parse("0.1.4").next_version("prerelease"))
+    '0.1.5-rc.1'
+
+
 Comparing Versions
 ------------------
 
diff --git a/semver.py b/semver.py
@@ -422,6 +422,51 @@ def compare(self, other):
 
         return rccmp
 
+    def next_version(self, part, prerelease_token="rc"):
+        """
+        Determines next version, preserving natural order.
+
+        This function is taking prereleases 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:
+
+        >>> str(semver.VersionInfo.parse("0.1.4").next_version("prerelease"))
+        '0.1.5-rc.1'
+
+        :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", # currently not used
+        }
+        if part not in validparts:
+            raise ValueError(
+                "Invalid part. Expected one of {validparts}, but got {part!r}".format(
+                    validparts=validparts, part=part
+                )
+            )
+        version = self
+        if (version.prerelease or version.build) and (
+            part == "patch"
+            or (part == "minor" and version.patch == 0)
+            or (part == "major" and version.minor == version.patch == 0)
+        ):
+            return version.replace(prerelease=None, build=None)
+
+        if part in ("major", "minor", "patch"):
+            return str(getattr(version, "bump_" + part)())
+
+        if not version.prerelease:
+            version = version.bump_patch()
+        return version.bump_prerelease(prerelease_token)
+
     @comparator
     def __eq__(self, other):
         return self.compare(other) == 0
@@ -898,6 +943,7 @@ def replace(version, **parts):
     return str(VersionInfo.parse(version).replace(**parts))
 
 
+# ---- CLI
 def cmd_bump(args):
     """
     Subcommand: Bumps a version.
@@ -953,6 +999,19 @@ def cmd_compare(args):
     return str(compare(args.version1, args.version2))
 
 
+def cmd_nextver(args):
+    """
+    Subcommand: Determines the next version, taking prereleases into account.
+
+    Synopsis: nextver <VERSION> <PART>
+
+    :param args: The parsed arguments
+    :type args: :class:`argparse.Namespace`
+    """
+    version = VersionInfo.parse(args.version)
+    return str(version.next_version(args.part))
+
+
 def createparser():
     """
     Create an :class:`argparse.ArgumentParser` instance.
@@ -995,6 +1054,15 @@ def createparser():
     parser_check.set_defaults(func=cmd_check)
     parser_check.add_argument("version", help="Version to check")
 
+    # Create the nextver subcommand
+    parser_nextver = s.add_parser(
+        "nextver", help="Determines the next version, taking prereleases into account."
+    )
+    parser_nextver.set_defaults(func=cmd_nextver)
+    parser_nextver.add_argument("version", help="Version to raise")
+    parser_nextver.add_argument(
+        "part", help="One of 'major', 'minor', 'patch', or 'prerelease'"
+    )
     return parser
 
 
diff --git a/test_semver.py b/test_semver.py
@@ -881,3 +881,39 @@ def mock_func():
 
     with pytest.deprecated_call():
         assert mock_func()
+
+
+def test_next_version_with_invalid_parts():
+    version = VersionInfo.parse("1.0.1")
+    with pytest.raises(ValueError):
+        version.next_version("invalid")
+
+
+@pytest.mark.parametrize(
+    "version, part, expected",
+    [
+        # major
+        ("1.0.4-rc.1", "major", "2.0.0"),
+        ("1.1.0-rc.1", "major", "2.0.0"),
+        ("1.1.4-rc.1", "major", "2.0.0"),
+        ("1.2.3", "major", "2.0.0"),
+        ("1.0.0-rc.1", "major", "1.0.0"),
+        # minor
+        ("0.2.0-rc.1", "minor", "0.2.0"),
+        ("0.2.5-rc.1", "minor", "0.3.0"),
+        ("1.3.1", "minor", "1.4.0"),
+        # patch
+        ("1.3.2", "patch", "1.3.3"),
+        ("0.1.5-rc.2", "patch", "0.1.5"),
+        # prerelease
+        ("0.1.4", "prerelease", "0.1.5-rc.1"),
+        ("0.1.5-rc.1", "prerelease", "0.1.5-rc.2"),
+        # special cases
+        ("0.2.0-rc.1", "patch", "0.2.0"),  # same as "minor"
+        ("1.0.0-rc.1", "patch", "1.0.0"),  # same as "major"
+        ("1.0.0-rc.1", "minor", "1.0.0"),  # same as "major"
+    ],
+)
+def test_next_version_with_versioninfo(version, part, expected):
+    ver = VersionInfo.parse(version)
+    assert str(ver.next_version(part)) == expected
