fix: fix_variable now doesn't update existing variables

Author: kantord

src/state_handler.js

@@ -11,8 +11,10 @@ const create_state_handler = () => {
   const state_handler = {
     'get_state': () => state,
     'init_variable': (variable, value) => {
-      state[variable] = value
-      handle_change()
+      if (state[variable] === undefined) {
+        state[variable] = value
+        handle_change()
+      }
     },
     'set_variable': (variable, value) => {
       state[variable] = value

src/state_handler.test.js

@@ -37,6 +37,17 @@ describe('state handler', () => {
     })
   })
 
+  it('init_variable does not update state if variable is defined', () => {
+    const state_handler = create_state_handler()
+    state_handler.init_variable('bar', false)
+    state_handler.init_variable('pi', 3.14)
+    state_handler.init_variable('pi', -3.14)
+    state_handler.get_state().should.deepEqual({
+      'bar': false,
+      'pi': 3.14
+    })
+  })
+
   it('set_variable should update state', () => {
     const state_handler = create_state_handler()
     state_handler.set_variable('foo', 42)
@@ -90,6 +101,15 @@ describe('state handler', () => {
     my_callback.should.be.calledOnce()
   })
 
+  it('no state change if init_variable is called twice on the same variable', () => {
+    const my_callback = sinon.spy(function() {state_handler.subscribe(my_callback)})
+    const state_handler = create_state_handler()
+    state_handler.subscribe(my_callback)
+    state_handler.init_variable('foo', 42)
+    state_handler.init_variable('foo', 42)
+    my_callback.should.be.calledOnce()
+  })
+
   it('callback should be called again with re-subscribe', () => {
     const my_callback = sinon.spy(function() {state_handler.subscribe(my_callback)})
     const state_handler = create_state_handler()