fix: properly bump versions between prereleases

commitizen/commands/bump.py

@@ -24,7 +24,11 @@
 )
 from commitizen.changelog_formats import get_changelog_format
 from commitizen.providers import get_provider
-from commitizen.version_schemes import InvalidVersion, get_version_scheme
+from commitizen.version_schemes import (
+    get_version_scheme,
+    InvalidVersion,
+    VersionProtocol,
+)
 
 logger = getLogger("commitizen")
 
@@ -226,11 +230,6 @@
                     "To avoid this error, manually specify the type of increment with `--increment`"
                 )
 
-            # Increment is removed when current and next version
-            # are expected to be prereleases.
-            if prerelease and current_version.is_prerelease:
-                increment = None
-
             new_version = current_version.bump(
                 increment,
                 prerelease=prerelease,
@@ -398,3 +397,33 @@
         if self.no_verify:
             commit_args.append("--no-verify")
         return " ".join(commit_args)
+
+    def find_previous_final_version(
+        self, current_version: VersionProtocol
+    ) -> VersionProtocol | None:
+        tag_format: str = self.bump_settings["tag_format"]
+        current = bump.normalize_tag(
+            current_version,
+            tag_format=tag_format,
+            scheme=self.scheme,
+        )
+
+        final_versions = []
+        for tag in git.get_tag_names():
+            assert tag
+            try:
+                version = self.scheme(tag)
+                if not version.is_prerelease or tag == current:
+                    final_versions.append(version)
+            except InvalidVersion:
+                continue
+
+        if not final_versions:
+            return None
+
+        final_versions = sorted(final_versions)  # type: ignore [type-var]
+        current_index = final_versions.index(current_version)
+        previous_index = current_index - 1
+        if previous_index < 0:
+            return None
+        return final_versions[previous_index]

commitizen/version_schemes.py

@@ -100,6 +100,7 @@
         prerelease_offset: int = 0,
         devrelease: int | None = None,
         is_local_version: bool = False,
+        force_bump: bool = False,
     ) -> Self:
         """
         Based on the given increment, generate the next bumped version according to the version scheme
@@ -146,6 +147,12 @@
         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]
@@ -171,20 +178,15 @@
         increments = [MAJOR, MINOR, PATCH]
         base = dict(zip_longest(increments, prev_release, fillvalue=0))
 
-        # This flag means that current version
-        # must remove its prerelease tag,
-        # so it doesn't matter the increment.
-        # Example: 1.0.0a0 with PATCH/MINOR -> 1.0.0
-        if not self.is_prerelease:
-            if increment == MAJOR:
-                base[MAJOR] += 1
-                base[MINOR] = 0
-                base[PATCH] = 0
-            elif increment == MINOR:
-                base[MINOR] += 1
-                base[PATCH] = 0
-            elif increment == PATCH:
-                base[PATCH] += 1
+        if increment == MAJOR:
+            base[MAJOR] += 1
+            base[MINOR] = 0
+            base[PATCH] = 0
+        elif increment == MINOR:
+            base[MINOR] += 1
+            base[PATCH] = 0
+        elif increment == PATCH:
+            base[PATCH] += 1
 
         return f"{base[MAJOR]}.{base[MINOR]}.{base[PATCH]}"
 
@@ -195,6 +197,7 @@
         prerelease_offset: int = 0,
         devrelease: int | None = None,
         is_local_version: bool = False,
+        force_bump: bool = False,
     ) -> Self:
         """Based on the given increment a proper semver will be generated.
 
@@ -212,9 +215,34 @@
             local_version = self.scheme(self.local).bump(increment)
             return self.scheme(f"{self.public}+{local_version}")  # type: ignore
         else:
-            base = self.increment_base(increment)
+            if not self.is_prerelease:
+                base = self.increment_base(increment)
+            elif force_bump:
+                base = self.increment_base(increment)
+            else:
+                base = f"{self.major}.{self.minor}.{self.micro}"
+                if increment == PATCH:
+                    pass
+                elif increment == MINOR:
+                    if self.micro != 0:
+                        base = self.increment_base(increment)
+                elif increment == MAJOR:
+                    if self.minor != 0 or self.micro != 0:
+                        base = self.increment_base(increment)
             dev_version = self.generate_devrelease(devrelease)
-            pre_version = self.generate_prerelease(prerelease, offset=prerelease_offset)
+            release = list(self.release)
+            if len(release) < 3:
+                release += [0] * (3 - len(release))
+            current_base = ".".join(str(part) for part in release)
+            if base == current_base:
+                pre_version = self.generate_prerelease(
+                    prerelease, offset=prerelease_offset
+                )
+            else:
+                base_version = cast(BaseVersion, self.scheme(base))
+                pre_version = base_version.generate_prerelease(
+                    prerelease, offset=prerelease_offset
+                )
             # TODO: post version
             return self.scheme(f"{base}{pre_version}{dev_version}")  # type: ignore
 

docs/bump.md

@@ -113,6 +113,34 @@ Generate a **changelog** along with the new version and tag when bumping.
 cz bump --changelog
 ```
 
+### `--prerelease`
+
+The bump is a pre-release bump, meaning that in addition to a possible version bump the new version receives a
+pre-release segment compatible with the bump’s version scheme, where the segment consist of a _phase_ and a
+non-negative number. Supported options for `--prerelease` are the following phase names  `alpha`, `beta`, or
+`rc` (release candidate). For more details, refer to the
+[Python Packaging User Guide](https://packaging.python.org/en/latest/specifications/version-specifiers/#pre-releases).
+
+Note that as per [semantic versioning spec](https://semver.org/#spec-item-9)
+
+> Pre-release versions have a lower precedence than the associated normal version. A pre-release version
+> indicates that the version is unstable and might not satisfy the intended compatibility requirements
+> as denoted by its associated normal version.
+
+For example, the following versions (using the [PEP 440](https://peps.python.org/pep-0440/) scheme) are ordered
+by their precedence and showcase how a release might flow through a development cycle:
+
+- `1.0.0` is the current published version
+- `1.0.1a0` after committing a `fix:` for pre-release
+- `1.1.0a1` after committing an additional `feat:` for pre-release
+- `1.1.0b0` after bumping a beta release
+- `1.1.0rc0` after bumping the release candidate
+- `1.1.0` next feature release
+
+Also note that bumping pre-releases _maintains linearity_: bumping of a pre-release with lower precedence than
+the current pre-release phase maintains the current phase of higher precedence. For example, if the current
+version is `1.0.0b1` then bumping with `--prerelease alpha` will continue to bump the “beta” phase.
+
 ### `--check-consistency`
 
 Check whether the versions defined in `version_files` and the version in commitizen

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()
@@ -227,6 +278,42 @@ def test_bump_command_prelease(mocker: MockFixture):
     assert tag_exists is True
 
 
+@pytest.mark.usefixtures("tmp_commitizen_project")
+def test_bump_command_prelease_increment(mocker: MockFixture):
+    # FINAL RELEASE
+    create_file_and_commit("fix: location")
+
+    testargs = ["cz", "bump", "--yes"]
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+    assert git.tag_exist("0.1.1")
+
+    # PRERELEASE
+    create_file_and_commit("fix: location")
+
+    testargs = ["cz", "bump", "--prerelease", "alpha", "--yes"]
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+
+    assert git.tag_exist("0.1.2a0")
+
+    create_file_and_commit("feat: location")
+
+    testargs = ["cz", "bump", "--prerelease", "alpha", "--yes"]
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+
+    assert git.tag_exist("0.2.0a0")
+
+    create_file_and_commit("feat!: breaking")
+
+    testargs = ["cz", "bump", "--prerelease", "alpha", "--yes"]
+    mocker.patch.object(sys, "argv", testargs)
+    cli.main()
+
+    assert git.tag_exist("1.0.0a0")
+
+
 @pytest.mark.usefixtures("tmp_commitizen_project")
 def test_bump_on_git_with_hooks_no_verify_disabled(mocker: MockFixture):
     """Bump commit without --no-verify"""

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)