feat: preserve prerelease linearity

Author: jenstroeger

commitizen/version_schemes.py

@@ -147,6 +147,12 @@ def generate_prerelease(
         if not prerelease:
             return ""
 
+        # prevent down-bumping the pre-release phase, e.g. from 'b1' to 'a2'
+        # https://packaging.python.org/en/latest/specifications/version-specifiers/#pre-releases
+        # https://semver.org/#spec-item-11
+        if self.is_prerelease and self.pre:
+            prerelease = max(prerelease, self.pre[0])
+
         # version.pre is needed for mypy check
         if self.is_prerelease and self.pre and prerelease.startswith(self.pre[0]):
             prev_prerelease: int = self.pre[1]

tests/commands/test_bump_command.py

@@ -208,17 +208,68 @@ def test_bump_command_increment_option(
 
 @pytest.mark.usefixtures("tmp_commitizen_project")
 def test_bump_command_prelease(mocker: MockFixture):
-    # PRERELEASE
     create_file_and_commit("feat: location")
 
+    # Create an alpha pre-release.
     testargs = ["cz", "bump", "--prerelease", "alpha", "--yes"]
     mocker.patch.object(sys, "argv", testargs)
     cli.main()
 
     tag_exists = git.tag_exist("0.2.0a0")
     assert tag_exists is True
 
-    # PRERELEASE BUMP CREATES VERSION WITHOUT PRERELEASE
+    # Create a beta pre-release.
+    testargs = ["cz", "bump", "--prerelease", "beta", "--yes"]
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+
+    tag_exists = git.tag_exist("0.2.0b0")
+    assert tag_exists is True
+
+    # With a current beta pre-release, bumping alpha must bump beta
+    # because we can't bump "backwards".
+    testargs = ["cz", "bump", "--prerelease", "alpha", "--yes"]
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+
+    tag_exists = git.tag_exist("0.2.0a1")
+    assert tag_exists is False
+    tag_exists = git.tag_exist("0.2.0b1")
+    assert tag_exists is True
+
+    # Create a rc pre-release.
+    testargs = ["cz", "bump", "--prerelease", "rc", "--yes"]
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+
+    tag_exists = git.tag_exist("0.2.0rc0")
+    assert tag_exists is True
+
+    # With a current rc pre-release, bumping alpha must bump rc.
+    testargs = ["cz", "bump", "--prerelease", "alpha", "--yes"]
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+
+    tag_exists = git.tag_exist("0.2.0a1")
+    assert tag_exists is False
+    tag_exists = git.tag_exist("0.2.0b2")
+    assert tag_exists is False
+    tag_exists = git.tag_exist("0.2.0rc1")
+    assert tag_exists is True
+
+    # With a current rc pre-release, bumping beta must bump rc.
+    testargs = ["cz", "bump", "--prerelease", "beta", "--yes"]
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+
+    tag_exists = git.tag_exist("0.2.0a2")
+    assert tag_exists is False
+    tag_exists = git.tag_exist("0.2.0b2")
+    assert tag_exists is False
+    tag_exists = git.tag_exist("0.2.0rc2")
+    assert tag_exists is True
+
+    # Create a final release from the current pre-release.
     testargs = ["cz", "bump"]
     mocker.patch.object(sys, "argv", testargs)
     cli.main()

tests/commands/test_changelog_command/test_changelog_incremental_with_prerelease_version_to_prerelease_version_beta_alpha_.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## 0.2.0a0 (2021-06-11)
+## 0.2.0b1 (2021-06-11)
 
 ## 0.2.0b0 (2021-06-11)
 

tests/commands/test_changelog_command/test_changelog_incremental_with_prerelease_version_to_prerelease_version_rc_alpha_.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## 0.2.0a0 (2021-06-11)
+## 0.2.0rc1 (2021-06-11)
 
 ## 0.2.0rc0 (2021-06-11)
 

tests/commands/test_changelog_command/test_changelog_incremental_with_prerelease_version_to_prerelease_version_rc_beta_.md

@@ -4,7 +4,7 @@ All notable changes to this project will be documented in this file.
 The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/),
 and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
 
-## 0.2.0b0 (2021-06-11)
+## 0.2.0rc1 (2021-06-11)
 
 ## 0.2.0rc0 (2021-06-11)
 

tests/test_version_scheme_pep440.py

@@ -43,10 +43,11 @@
     (("4.5.0+0.2.0", "MAJOR", None, 0, None), "4.5.0+1.0.0"),
 ]
 
-# this cases should be handled gracefully
-unexpected_cases = [
-    (("0.1.1rc0", None, "alpha", 0, None), "0.1.1a0"),
-    (("0.1.1b1", None, "alpha", 0, None), "0.1.1a0"),
+# never bump backwards on pre-releases
+linear_prerelease_cases = [
+    (("0.1.1b1", None, "alpha", 0, None), "0.1.1b2"),
+    (("0.1.1rc0", None, "alpha", 0, None), "0.1.1rc1"),
+    (("0.1.1rc0", None, "beta", 0, None), "0.1.1rc1"),
 ]
 
 weird_cases = [
@@ -145,7 +146,7 @@
         tdd_cases,
         weird_cases,
         simple_flow,
-        unexpected_cases,
+        linear_prerelease_cases,
         prerelease_cases,
     ),
 )

tests/test_version_scheme_semver.py

@@ -44,10 +44,11 @@
     (("4.5.0+0.2.0", "MAJOR", None, 0, None), "4.5.0+1.0.0"),
 ]
 
-# this cases should be handled gracefully
-unexpected_cases = [
-    (("0.1.1rc0", None, "alpha", 0, None), "0.1.1-a0"),
-    (("0.1.1b1", None, "alpha", 0, None), "0.1.1-a0"),
+# never bump backwards on pre-releases
+linear_prerelease_cases = [
+    (("0.1.1b1", None, "alpha", 0, None), "0.1.1-b2"),
+    (("0.1.1rc0", None, "alpha", 0, None), "0.1.1-rc1"),
+    (("0.1.1rc0", None, "beta", 0, None), "0.1.1-rc1"),
 ]
 
 weird_cases = [
@@ -84,7 +85,7 @@
 
 @pytest.mark.parametrize(
     "test_input, expected",
-    itertools.chain(tdd_cases, weird_cases, simple_flow, unexpected_cases),
+    itertools.chain(tdd_cases, weird_cases, simple_flow, linear_prerelease_cases),
 )
 def test_bump_semver_version(test_input, expected):
     current_version = test_input[0]