s/block/early return

lib/minisign/nacl.rb

@@ -3,29 +3,27 @@
 module Minisign
   # A module that invokes RbNaCl with user-focused actionable error messages.
   module NaCl
-    def self.safely
-      yield
-    rescue NameError
+    def self.assert_libsodium_dependency_met!
+      return if RbNaCl.const_defined?(:PasswordHash)
+
       raise Minisign::LibSodiumDependencyError, 'libsodium is not installed!'
     end
 
     module Hash
       # see RbNaCl::Hash::Blake2b
       module Blake2b
         def self.digest(*args)
-          NaCl.safely do
-            RbNaCl::Hash::Blake2b.digest(*args)
-          end
+          NaCl.assert_libsodium_dependency_met!
+          RbNaCl::Hash::Blake2b.digest(*args)
         end
       end
     end
 
     # see RbNaCl::PasswordHash
     module PasswordHash
       def self.scrypt(*args)
-        NaCl.safely do
-          RbNaCl::PasswordHash.scrypt(*args)
-        end
+        NaCl.assert_libsodium_dependency_met!
+        RbNaCl::PasswordHash.scrypt(*args)
       end
     end
   end

spec/minisign/nacl_spec.rb

@@ -3,9 +3,11 @@
 describe Minisign::NaCl do
   it 'raises LibSodiumDependencyError if libsodium not installed' do
     hash = RbNaCl.send(:remove_const, :Hash)
+    password_hash = RbNaCl.send(:remove_const, :PasswordHash)
     expect do
       Minisign::NaCl::Hash::Blake2b.digest('message', { digest_size: 32 })
     end.to raise_error(Minisign::LibSodiumDependencyError)
     RbNaCl.const_set(:Hash, hash)
+    RbNaCl.const_set(:PasswordHash, password_hash)
   end
 end