From 59f1e646968f8fc5360613d417b944d5902a3c75 Mon Sep 17 00:00:00 2001
From: Omar Vazquez <VzqzAc@users.noreply.github.com>
Date: Sat, 17 Oct 2020 00:19:46 -0500
Subject: [PATCH] Add --prevent-empty-failure flag

This flag aims to prevent a failure throw when there are no files that
match either the given glob or the default one, this can be helpful in
some cases such as some pre-commit hooks that run against the diff-ed
files, for example:

Commiting files that do not include any erb extension, then, running
linters as part of a pre-commit check, including (as an example) rubocop,
reek, stylelint, fasterer, and erb-lint, would throw an error since there are no
files to run erb-lint against, preventing the user to properly create a
commit.
---
 lib/erb_lint/cli.rb       |  8 ++++++++
 spec/erb_lint/cli_spec.rb | 13 +++++++++++++
 2 files changed, 21 insertions(+)

diff --git a/lib/erb_lint/cli.rb b/lib/erb_lint/cli.rb
index 46c204f6..0e53d279 100644
--- a/lib/erb_lint/cli.rb
+++ b/lib/erb_lint/cli.rb
@@ -42,6 +42,10 @@ def run(args = ARGV)
       if !@files.empty? && lint_files.empty?
         failure!("no files found...\n")
       elsif lint_files.empty?
+        if @options[:prevent_empty_failure]
+          success!('No files found or given, skipping because "--prevent-empty-failure" flag was passed')
+        end
+
         failure!("no files found or given, specify files or config...\n#{option_parser}")
       end
 
@@ -280,6 +284,10 @@ def option_parser
           @options[:autocorrect] = config
         end
 
+        opts.on("--prevent-empty-failure", "Skip the linter check if no files match the given glob [default: #{DEFAULT_LINT_ALL_GLOB}]") do
+          @options[:prevent_empty_failure] = true
+        end
+
         opts.on_tail("-h", "--help", "Show this message") do
           success!(opts)
         end
diff --git a/spec/erb_lint/cli_spec.rb b/spec/erb_lint/cli_spec.rb
index 794e0cb7..dd26c863 100644
--- a/spec/erb_lint/cli_spec.rb
+++ b/spec/erb_lint/cli_spec.rb
@@ -273,6 +273,19 @@ def run(_processed_source)
       end
     end
 
+    context 'with --prevent-empty-failure' do
+      let(:args) { ['--prevent-empty-failure'] }
+
+      context 'when there are no files' do
+        before do
+          allow(cli).to(receive(:glob).and_return("no/file/glob"))
+        end
+
+        it { expect { subject }.not_to output(/no files found/).to_stderr }
+        it { expect { subject }.to output(/No files found or given, skipping because "--prevent-empty-failure" flag was passed/).to_stdout }
+      end
+    end
+
     context 'with unknown argument' do
       let(:args) { ['--foo'] }