Add a new function "try_get_value"

* Extracts a value from a deeply-nested data structure
* Returns default if a value could not be extracted

1 files changed, 47 insertions, 0 deletions

diff --git a/spec/acceptance/try_get_value_spec.rb b/spec/acceptance/try_get_value_spec.rb
new file mode 100755
index 0000000..46b1c4d
--- /dev/null
+++ b/spec/acceptance/try_get_value_spec.rb
@@ -0,0 +1,47 @@
+#! /usr/bin/env ruby -S rspec
+require 'spec_helper_acceptance'
+
+describe 'try_get_value function', :unless => UNSUPPORTED_PLATFORMS.include?(fact('operatingsystem')) do
+  describe 'success' do
+    it 'try_get_valuees a value' do
+      pp = <<-EOS
+      $data = {
+        'a' => { 'b' => 'passing'}
+      }
+
+      $tests = try_get_value($a, 'a/b')
+      notice(inline_template('tests are <%= @tests.inspect %>'))
+      EOS
+
+      apply_manifest(pp, :catch_failures => true) do |r|
+        expect(r.stdout).to match(/tests are "passing"/)
+      end
+    end
+  end
+  describe 'failure' do
+    it 'uses a default value' do
+      pp = <<-EOS
+      $data = {
+        'a' => { 'b' => 'passing'}
+      }
+
+      $tests = try_get_value($a, 'c/d', 'using the default value')
+      notice(inline_template('tests are <%= @tests.inspect %>'))
+      EOS
+
+      apply_manifest(pp, :expect_failures => true) do |r|
+        expect(r.stdout).to match(/using the default value/)
+      end
+    end
+
+    it 'raises error on incorrect number of arguments' do
+      pp = <<-EOS
+      $o = try_get_value()
+      EOS
+
+      apply_manifest(pp, :expect_failures => true) do |r|
+        expect(r.stderr).to match(/wrong number of arguments/i)
+      end
+    end
+  end
+end