From fb3075d7e5105cb491bebb8de2793d4a3939154c Mon Sep 17 00:00:00 2001
From: Hunter Haugen <hunter@puppet.com>
Date: Fri, 16 Feb 2018 13:56:41 -0800
Subject: [PATCH] Raise error instead of unhelpful behavior for --since-tag or
 --due-tag

Fixes #604

The --since-tag and --due-tag arguments exist to specify tags between
which the changelog should be generated. Prior to this change if these
tags do not exist then GCG continues to generate the entire changelog
which is not what the user requested. This change causes an error
informing the user that their specified tags do not exist so their
request could not be completed.

Other arguments with similar behavior such as --exclude-tags and
--exclude-tags-regex may continue to only give a warning in case the
user made a mistake, but should not error as nonexistent tags are
trivially excluded.
---
 .../generator/generator_tags.rb               |  4 ++--
 spec/unit/generator/generator_tags_spec.rb    | 24 ++++---------------
 2 files changed, 6 insertions(+), 22 deletions(-)

diff --git a/lib/github_changelog_generator/generator/generator_tags.rb b/lib/github_changelog_generator/generator/generator_tags.rb
index d8f4534ab..7568a1790 100644
--- a/lib/github_changelog_generator/generator/generator_tags.rb
+++ b/lib/github_changelog_generator/generator/generator_tags.rb
@@ -135,7 +135,7 @@ def filter_since_tag(all_tags)
                             []
                           end
         else
-          Helper.log.warn "Warning: can't find tag #{tag}, specified with --since-tag option."
+          raise ChangelogGeneratorError, "Error: can't find tag #{tag}, specified with --since-tag option."
         end
       end
       filtered_tags
@@ -155,7 +155,7 @@ def filter_due_tag(all_tags)
                             []
                           end
         else
-          Helper.log.warn "Warning: can't find tag #{tag}, specified with --due-tag option."
+          raise ChangelogGeneratorError, "Error: can't find tag #{tag}, specified with --due-tag option."
         end
       end
       filtered_tags
diff --git a/spec/unit/generator/generator_tags_spec.rb b/spec/unit/generator/generator_tags_spec.rb
index d9dc6b46c..515da2302 100644
--- a/spec/unit/generator/generator_tags_spec.rb
+++ b/spec/unit/generator/generator_tags_spec.rb
@@ -191,24 +191,16 @@ def tags_from_strings(tags_strings)
 
       context "with invalid since tag" do
         let(:generator) { GitHubChangelogGenerator::Generator.new(since_tag: "Invalid tag") }
-        it { is_expected.to be_a Array }
-        it { is_expected.to match_array(tags_from_strings(%w[1 2 3])) }
+        it { expect { subject }.to raise_error(GitHubChangelogGenerator::ChangelogGeneratorError) }
       end
     end
 
     context "with empty array" do
       subject { generator.filter_since_tag(tags_from_strings(%w[])) }
 
-      context "with valid since tag" do
-        let(:generator) { GitHubChangelogGenerator::Generator.new(since_tag: "2") }
-        it { is_expected.to be_a Array }
-        it { is_expected.to match_array(tags_from_strings(%w[])) }
-      end
-
       context "with invalid since tag" do
         let(:generator) { GitHubChangelogGenerator::Generator.new(since_tag: "Invalid tag") }
-        it { is_expected.to be_a Array }
-        it { is_expected.to match_array(tags_from_strings(%w[])) }
+        it { expect { subject }.to raise_error(GitHubChangelogGenerator::ChangelogGeneratorError) }
       end
     end
   end
@@ -225,24 +217,16 @@ def tags_from_strings(tags_strings)
 
       context "with invalid due tag" do
         let(:generator) { GitHubChangelogGenerator::Generator.new(due_tag: "Invalid tag") }
-        it { is_expected.to be_a Array }
-        it { is_expected.to match_array(tags_from_strings(%w[1 2 3])) }
+        it { expect { subject }.to raise_error(GitHubChangelogGenerator::ChangelogGeneratorError) }
       end
     end
 
     context "with empty array" do
       subject { generator.filter_due_tag(tags_from_strings(%w[])) }
 
-      context "with valid due tag" do
-        let(:generator) { GitHubChangelogGenerator::Generator.new(due_tag: "2") }
-        it { is_expected.to be_a Array }
-        it { is_expected.to match_array(tags_from_strings(%w[])) }
-      end
-
       context "with invalid due tag" do
         let(:generator) { GitHubChangelogGenerator::Generator.new(due_tag: "Invalid tag") }
-        it { is_expected.to be_a Array }
-        it { is_expected.to match_array(tags_from_strings(%w[])) }
+        it { expect { subject }.to raise_error(GitHubChangelogGenerator::ChangelogGeneratorError) }
       end
     end
   end