[features] check that quiet mode really outputs nothing.

Previously it was checking the output contained a null string within it.

features/cache_restore.feature

@@ -86,14 +86,16 @@ Feature: cache_restore
   Scenario: --quiet is accepted
     Given valid cache metadata
     When I run cache_restore with -i metadata.xml -o metadata.bin --quiet
-    Then it should pass with:
+    Then it should pass
+    And the output should contain exactly:
     """
     """
 
   Scenario: -q is accepted
     Given valid cache metadata
     When I run cache_restore with -i metadata.xml -o metadata.bin -q
-    Then it should pass with:
+    Then it should pass
+    And the output should contain exactly:
     """
     """
 

features/era_restore.feature

@@ -69,14 +69,16 @@ Feature: era_restore
   Scenario: --quiet is accepted
     Given valid era metadata
     When I run era_restore with -i metadata.xml -o metadata.bin --quiet
-    Then it should pass with:
+    Then it should pass
+    And the output should contain exactly:
     """
     """
 
   Scenario: -q is accepted
     Given valid era metadata
     When I run era_restore with -i metadata.xml -o metadata.bin -q
-    Then it should pass with:
+    Then it should pass
+    And the output should contain exactly:
     """
     """
 

features/step_definitions/cache_steps.rb

@@ -80,9 +80,9 @@ end
 Given(/^valid cache metadata$/) do
   in_current_dir do
     system("cache_xml create --nr-cache-blocks uniform[1000..5000] --nr-mappings uniform[500..1000] > #{xml_file}")
+    system("dd if=/dev/zero of=#{dev_file} bs=4k count=1024 > /dev/null")
   end
 
-  run_simple("dd if=/dev/zero of=#{dev_file} bs=4k count=1024")
   run_simple("cache_restore -i #{xml_file} -o #{dev_file}")
 end
 

features/step_definitions/era_steps.rb

@@ -32,8 +32,8 @@ end
 Given(/^valid era metadata$/) do
   in_current_dir do
     system("era_xml create --nr-blocks 100 --nr-writesets 2 --current-era 1000 > #{xml_file}")
+    system("dd if=/dev/zero of=#{dev_file} bs=4k count=1024 > /dev/null")
   end
 
-  run_simple("dd if=/dev/zero of=#{dev_file} bs=4k count=1024")
   run_simple("era_restore -i #{xml_file} -o #{dev_file}")
 end

features/step_definitions/thin_steps.rb

@@ -1,9 +1,9 @@
 Given(/^valid thin metadata$/) do
   in_current_dir do
     system("thinp_xml create --nr-thins uniform[4..9] --nr-mappings uniform[1000..10000] > #{xml_file}")
+    system("dd if=/dev/zero of=#{dev_file} bs=4k count=1024 > /dev/null")
   end
 
-  run_simple("dd if=/dev/zero of=#{dev_file} bs=4k count=1024")
   run_simple("thin_restore -i #{xml_file} -o #{dev_file}")
 end
 

features/thin_restore.feature

@@ -58,14 +58,16 @@ Feature: thin_restore
   Scenario: --quiet is accepted
     Given valid thin metadata
     When I run thin_restore with -i metadata.xml -o metadata.bin --quiet
-    Then it should pass with:
+    Then it should pass
+    And the output should contain exactly:
     """
     """
 
   Scenario: -q is accepted
     Given valid thin metadata
     When I run thin_restore with -i metadata.xml -o metadata.bin -q
-    Then it should pass with:
+    Then it should pass
+    And the output should contain exactly:
     """
     """