feat: Add support for showing unreleased changelog

Fixes #134

semantic_release/cli.py

@@ -110,7 +110,10 @@ def changelog(**kwargs):
     previous_version = get_previous_version(current_version)
     debug('changelog got previous_version', previous_version)
 
-    log = generate_changelog(previous_version, current_version)
+    if kwargs['unreleased']:
+        log = generate_changelog(current_version, None)
+    else:
+        log = generate_changelog(previous_version, current_version)
     click.echo(markdown_changelog(current_version, log, header=False))
 
     debug('noop={}, post={}'.format(kwargs.get('noop'), kwargs.get('post')))
@@ -244,6 +247,10 @@ def cmd_publish(**kwargs):
 
 @main.command(name='changelog', help=changelog.__doc__)
 @common_options
+@click.option(
+    '--unreleased/--released',
+    help="Decides whether to show the released or unreleased changelog."
+)
 def cmd_changelog(**kwargs):
     try:
         return changelog(**kwargs)

tests/test_cli.py

@@ -259,4 +259,5 @@ def test_changelog_should_call_functions(mocker, runner):
     mock_changelog = mocker.patch('semantic_release.cli.changelog', return_value=True)
     result = runner.invoke(main, ['changelog'])
     assert result.exit_code == 0
-    mock_changelog.assert_called_once_with(noop=False, post=False, force_level=None, retry=False)
+    mock_changelog.assert_called_once_with(
+        noop=False, post=False, force_level=None, retry=False, unreleased=False)