fix(overmind): add sync transition warning and fix entry transitions

Author: christianalfoni

packages/node_modules/overmind/src/config/statecharts.test.ts

@@ -683,5 +683,75 @@ describe('Statecharts', () => {
     })).toEqual(false)
     expect(instance.state.count).toBe(3)
   })
+
+  test.only('should run entry and exit actions when transitioning within a transition', async () => {
+    const step: AsyncAction = async ({ state, actions }) => {
+      state.actionEvents.push('step')
+      await Promise.resolve()
+      actions.step2()
+    }
+    const step2: Action = ({ state }) => {
+      state.actionEvents.push('step2')
+    }
+    const entry: Action = ({ state }) => {
+      state.actionEvents.push('entry')
+    }
+    const exit: Action = ({ state }) => {
+      state.actionEvents.push('exit')
+    }
+
+    const config = {
+      state: {
+        actionEvents: [] as string[],
+      },
+      actions: {
+        step,
+        step2,
+        entry,
+        exit
+      },
+    }
+
+    const chart: Statechart<typeof config, {
+      foo: void
+      bar: void
+      baz: void
+    }> = {
+      initial: 'foo',
+      states: {
+        foo: {
+          on: {
+            step: 'bar'
+          },
+          exit: 'exit',
+        },
+        bar: {
+          entry: 'entry',
+          on: {
+            step2: 'baz'
+          }
+        },
+        baz: {}
+      },
+    }
+
+    interface Action<Input = void, Output = void>
+      extends IAction<typeof config, Input, Output> {}
+    interface AsyncAction<Input = void, Output = void>
+      extends IAction<typeof config, Input, Promise<Output>> {}
+
+    const instance = createOvermind(statecharts(config, {
+      id1: chart
+    }))
+
+    await instance.actions.step()
+
+    expect(instance.state.actionEvents).toEqual([
+      'exit',
+      'step',
+      'entry',
+      'step2',
+    ])
+  })
 
 })

packages/node_modules/overmind/src/config/statecharts.ts

@@ -219,6 +219,8 @@ export function statecharts<C extends IConfiguration, Charts extends Statecharts
     )
   }
 
+  let currentTransitionAction: string | null = null
+
   return {
     onInitialize: ((context, instance) => {
       if (config.onInitialize) {
@@ -294,9 +296,13 @@ export function statecharts<C extends IConfiguration, Charts extends Statecharts
       aggr[key] = pipe(
         map(function getTransition({ state, execution }: any, payload) {
           const stateTarget = getTarget(state, execution.namespacePath)
+          const canTransition = stateTarget.actions[key]
+          if (currentTransitionAction && !canTransition) {
+            console.warn(`Overmind Statecharts: Transition action "${currentTransitionAction}" is calling transition action "${key}" synchronously. The previous transition is not done yet and "${key}" will be ignored. Consider calling it asynchronously `)
+          }
 
           return {
-            canTransition: stateTarget.actions[key],
+            canTransition,
             payload,
           }
         }),
@@ -379,7 +385,7 @@ export function statecharts<C extends IConfiguration, Charts extends Statecharts
               if (
                 target.entry &&
                 newStatePath[traverseNewPath.length - 1] !==
-                traverseNewPath[traverseNewPath.length - 1]
+                stateTarget.states[transitionAction.index][traverseNewPath.length - 1]
               ) {
                 entryActions.push(target.entry)
               }
@@ -396,21 +402,26 @@ export function statecharts<C extends IConfiguration, Charts extends Statecharts
             }  
           })
 
-          // Transition to new state
-          stateTarget.states = newStates
-
+          currentTransitionAction = key
+          // Run the action that caused the transition
           if (config.actions) {
             config.actions[key](context, payload)
           }
-          
-          // Run enters          
 
+          currentTransitionAction = null
+          
+          // Transition to new state
+          stateTarget.states = newStates
+          
+          // Run entry actions          
           entryActions.forEach((entryAction) => {
             if (config.actions) {
               config.actions[entryAction](context, payload)
             }  
           })
 
+          
+
           if (process.env.NODE_ENV === 'development' && currentInstance.devtools) {
             currentInstance.devtools.send({
               type: 'chart',