From 3dcdb96c876c7d168e224661fcc6dc76fdf831b8 Mon Sep 17 00:00:00 2001
From: Javier Santacruz <javier.santacruz@avature.net>
Date: Thu, 22 Oct 2020 13:55:12 +0200
Subject: [PATCH] Allow start/end checks on empty strings

When using this library function on strings that come from a parameter,
they might be empty sometimes, rendering it difficult to use, having to
force hacks like.

    "_${source}".stdlib::start_with('_puppet:///modules/')

Where `_` is added to make sure that the string is never empty.

In Ruby the `start_with?` function allows being used on empty strings,
and it returns `false` for any assertion to be done:

    p ''.start_with?('test')
    false

Also in Python the `startswith()` method returns `false` for empty
strings:

    In [1]: print(''.startswith('test'))
    False

As this logic seems the most extended and allows for a wider use of the
library, removing corner cases when the string comes empty.
---
 lib/puppet/functions/stdlib/end_with.rb   | 2 +-
 lib/puppet/functions/stdlib/start_with.rb | 2 +-
 spec/functions/end_with_spec.rb           | 6 +-----
 spec/functions/startswith_spec.rb         | 1 +
 4 files changed, 4 insertions(+), 7 deletions(-)

diff --git a/lib/puppet/functions/stdlib/end_with.rb b/lib/puppet/functions/stdlib/end_with.rb
index 2be98e6a6..fc83f70aa 100644
--- a/lib/puppet/functions/stdlib/end_with.rb
+++ b/lib/puppet/functions/stdlib/end_with.rb
@@ -10,7 +10,7 @@
   #    'foobar'.stdlib::end_with(['foo', 'baz']) => false
   # @return [Boolean] True or False
   dispatch :end_with do
-    param 'String[1]', :test_string
+    param 'String', :test_string
     param 'Variant[String[1],Array[String[1], 1]]', :suffixes
     return_type 'Boolean'
   end
diff --git a/lib/puppet/functions/stdlib/start_with.rb b/lib/puppet/functions/stdlib/start_with.rb
index 294c72a54..28f01bbd5 100644
--- a/lib/puppet/functions/stdlib/start_with.rb
+++ b/lib/puppet/functions/stdlib/start_with.rb
@@ -10,7 +10,7 @@
   #   'foObar'.stdlib::start_with(['bar', 'baz']) => false
   # @return [Boolean] True or False
   dispatch :start_with do
-    param 'String[1]', :test_string
+    param 'String', :test_string
     param 'Variant[String[1],Array[String[1], 1]]', :prefixes
     return_type 'Boolean'
   end
diff --git a/spec/functions/end_with_spec.rb b/spec/functions/end_with_spec.rb
index a9b95eca8..5c1e8a974 100644
--- a/spec/functions/end_with_spec.rb
+++ b/spec/functions/end_with_spec.rb
@@ -1,14 +1,10 @@
 require 'spec_helper'
 
 describe 'stdlib::end_with' do
+  it { is_expected.to run.with_params('', 'bar').and_return(false) }
   it { is_expected.to run.with_params('foobar', 'bar').and_return(true) }
   it { is_expected.to run.with_params('foobar', 'foo').and_return(false) }
   it { is_expected.to run.with_params('foobar', ['foo', 'baz']).and_return(false) }
-  it do
-    is_expected.to run.with_params('', 'foo').and_raise_error(
-      ArgumentError, %r{'stdlib::end_with' parameter 'test_string' expects a String\[1\] value}
-    )
-  end
   it do
     is_expected.to run.with_params('foobar', '').and_raise_error(
       ArgumentError, %r{'stdlib::end_with' parameter 'suffixes' expects a value of type String\[1\] or Array\[String\[1\], 1\]}
diff --git a/spec/functions/startswith_spec.rb b/spec/functions/startswith_spec.rb
index 382088372..a25919230 100644
--- a/spec/functions/startswith_spec.rb
+++ b/spec/functions/startswith_spec.rb
@@ -5,6 +5,7 @@
   it { is_expected.to run.with_params.and_raise_error(ArgumentError, %r{expects 2 arguments, got none}i) }
   it { is_expected.to run.with_params('').and_raise_error(ArgumentError, %r{expects 2 arguments, got 1}) }
 
+  it { is_expected.to run.with_params('', 'foo').and_return(false) }
   it { is_expected.to run.with_params('foobar', 'foo').and_return(true) }
   it { is_expected.to run.with_params('foObar', ['bar', 'baz']).and_return(false) }
 end