(FACT-3207) Don't rescue NoMethodError in base resolver

This commit removes the logic to specifically rescue for just NoMethodError.
Instead, since NameError is a superclass of NoMethodError, NoMethodErrors will
be rescued when NameError is rescued and log at the error level instead of the
debug level. By doing this, bugs in resolvers are no longer hidden.

This commit also fixes various bugs in resolvers such as calling methods on nil
objects and requiring/relying gems that may not be installed to resolve facts.

lib/facter/resolvers/augeas.rb

@@ -17,6 +17,9 @@ def read_augeas_version(fact_name)
           @fact_list[:augeas_version] ||= read_augeas_from_gem
 
           @fact_list[fact_name]
+        rescue LoadError => e
+          log.debug("Resolving fact #{fact_name}, but got #{e} at #{e.backtrace[0]}")
+          @fact_list[:augeas_version] = nil
         end
 
         def read_augeas_from_cli

lib/facter/resolvers/base_resolver.rb

@@ -27,11 +27,8 @@ def self.resolve(fact_name, options = {})
 
           cache_nil_for_unresolved_facts(fact_name)
         end
-      rescue NoMethodError => e
-        log.debug("Could not resolve #{fact_name}, got #{e} at #{e.backtrace[0]}")
-        @fact_list[fact_name] = nil
       rescue LoadError, NameError => e
-        log.debug("Resolving fact #{fact_name}, but got #{e} at #{e.backtrace[0]}")
+        log.error("Resolving fact #{fact_name}, but got #{e} at #{e.backtrace[0]}")
         @fact_list[fact_name] = nil
       end
 

lib/facter/resolvers/dmi.rb

@@ -36,7 +36,7 @@ def read_facts(fact_name)
             return unless File.directory?('/sys/class/dmi')
 
             file_content = Facter::Util::FileHelper.safe_read("/sys/class/dmi/id/#{fact_name}", nil)
-                                                   .encode('UTF-8', invalid: :replace)
+            file_content = file_content.encode('UTF-8', invalid: :replace) if file_content
             if files.include?(fact_name.to_s) && file_content
               file_content = file_content.strip
               @fact_list[fact_name] = file_content unless file_content.empty?

lib/facter/resolvers/solaris/mountpoints.rb

@@ -25,7 +25,7 @@ def read_mounts(fact_name) # rubocop:disable Metrics/MethodLength
             @mounts = []
             @auto_home_paths = []
 
-            Facter::Util::Resolvers::FilesystemHelper.read_mountpoints.each do |fs|
+            Facter::Util::Resolvers::FilesystemHelper.read_mountpoints&.each do |fs|
               if fs.name == 'auto_home'
                 @auto_home_paths << fs.mount_point
                 next

lib/facter/resolvers/windows/timezone.rb

@@ -22,7 +22,7 @@ def determine_timezone
 
           def codepage
             result = codepage_from_api
-            result.empty? ? codepage_from_registry : result
+            result&.empty? ? codepage_from_registry : result
           end
 
           def codepage_from_registry

lib/facter/util/resolvers/filesystem_helper.rb

@@ -33,7 +33,7 @@ def compute_capacity(used, total)
           private
 
           def force_utf(mounts)
-            mounts.each do |mount|
+            mounts&.each do |mount|
               mount.name.force_encoding('UTF-8')
               mount.mount_type.force_encoding('UTF-8')
               mount.mount_point.force_encoding('UTF-8')

spec/facter/resolvers/augeas_spec.rb

@@ -77,7 +77,7 @@
         allow(Facter::Resolvers::Augeas).to receive(:require).with('augeas').and_raise(exception)
       end
 
-      it 'raises a LoadError error' do
+      it 'rescues LoadError error and logs at debug level' do
         augeas.resolve(:augeas_version)
 
         expect(log_spy).to have_received(:debug).with(/Resolving fact augeas_version, but got load_error_message/)

spec/facter/resolvers/base_resolver_spec.rb

@@ -77,13 +77,13 @@ def self.post_resolve(fact_name, _options)
     context 'when Load Error is raised' do
       before do
         allow(resolver).to receive(:post_resolve).and_raise(LoadError)
-        allow(Facter::Log).to receive(:new).with(resolver).and_return(instance_double(Facter::Log, debug: nil))
+        allow(Facter::Log).to receive(:new).with(resolver).and_return(instance_double(Facter::Log, error: nil))
       end
 
-      it 'logs the Load Error exception' do
+      it 'logs the Load Error exception at the error level' do
         resolver.resolve(fact)
 
-        expect(resolver.log).to have_received(:debug).with(/Resolving fact #{fact}, but got LoadError/)
+        expect(resolver.log).to have_received(:error).with(/Resolving fact #{fact}, but got LoadError/)
       end
 
       it 'sets the fact to nil' do