Adds error? method to check whether the process exited successfully. This allows the user to use custom error-handling logic. error! now uses error? internally.

2 files changed, 30 insertions, 8 deletions

diff --git a/lib/mixlib/shellout.rb b/lib/mixlib/shellout.rb
index 66faa40..e4e0435 100644
--- a/lib/mixlib/shellout.rb
+++ b/lib/mixlib/shellout.rb
@@ -49,8 +49,8 @@ module Mixlib
     # Working directory for the subprocess. Normally set via options to new
     attr_accessor :cwd
 
-    # An Array of acceptable exit codes. #error! uses this list to determine if
-    # the command was successful. Normally set via options to new
+    # An Array of acceptable exit codes. #error? (and #error!) use this list
+    # to determine if the command was successful. Normally set via options to new
     attr_accessor :valid_exit_codes
 
     # When live_stream is set, stdout of the subprocess will be copied to it as
@@ -227,17 +227,21 @@ module Mixlib
       super
     end
 
-    # Checks the +exitstatus+ against the set of +valid_exit_codes+. If
-    # +exitstatus+ is not in the list of +valid_exit_codes+, calls +invalid!+,
-    # which raises an Exception.
+    # Checks the +exitstatus+ against the set of +valid_exit_codes+.
+    # === Returns
+    # +true+ if +exitstatus+ is not in the list of +valid_exit_codes+, false
+    # otherwise.
+    def error?
+      !Array(valid_exit_codes).include?(exitstatus)
+    end
+
+    # If #error? is true, calls +invalid!+, which raises an Exception.
     # === Returns
     # nil::: always returns nil when it does not raise
     # === Raises
     # ::ShellCommandFailed::: via +invalid!+
     def error!
-      unless Array(valid_exit_codes).include?(exitstatus)
-        invalid!("Expected process to exit with #{valid_exit_codes.inspect}, but received '#{exitstatus}'")
-      end
+      invalid!("Expected process to exit with #{valid_exit_codes.inspect}, but received '#{exitstatus}'") if error?
     end
 
     # Raises a ShellCommandFailed exception, appending the
diff --git a/spec/mixlib/shellout_spec.rb b/spec/mixlib/shellout_spec.rb
index 0a6f9b2..3d0a04f 100644
--- a/spec/mixlib/shellout_spec.rb
+++ b/spec/mixlib/shellout_spec.rb
@@ -750,6 +750,24 @@ describe Mixlib::ShellOut do
           lambda { executed_cmd.invalid!("I expected this to exit 42, not 0") }.should raise_error(Mixlib::ShellOut::ShellCommandFailed)
         end
       end
+
+      describe "#error?" do
+        context 'when exiting with invalid code' do
+          let(:exit_code) { 2 }
+
+          it "should return true" do
+            executed_cmd.error?.should be_true
+          end
+        end
+
+        context 'when exiting with valid code' do
+          let(:exit_code) { 0 }
+
+          it "should return false" do
+            executed_cmd.error?.should be_false
+          end
+        end
+      end
     end
 
     context "when handling the subprocess" do