Define state constants

gocardless · Aug 2, 2023 · bd8e15a · bd8e15a
1 parent 3c70691
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diff --git a/README.md b/README.md
@@ -366,6 +366,16 @@ Machine.successors
 }
 ```
 
+## Class constants
+Each machine's state will turn into a constant:
+```ruby
+Machine.state(:some_state, initial: true)
+Machine.state(:another_state)
+
+Machine::SOME_STATE #=> "some_state"
+Machine::ANOTHER_STATE # => "another_state"
+```
+
 ## Instance methods
 
 #### `Machine#current_state`

diff --git a/lib/statesman/machine.rb b/lib/statesman/machine.rb
@@ -39,6 +39,8 @@ def state(name, options = { initial: false })
           validate_initial_state(name)
           @initial_state = name
         end
+        const_set(name.upcase, name)
+
         states << name
       end
 

diff --git a/spec/statesman/machine_spec.rb b/spec/statesman/machine_spec.rb
@@ -13,6 +13,10 @@
 
     specify { expect(machine.states).to eq(%w[x y]) }
 
+    specify { expect(machine::X).to eq "x" }
+
+    specify { expect(machine::Y).to eq "y" }
+
     context "initial" do
       before { machine.state(:x, initial: true) }