update exception messages with info about threading. Update threading tests

Author: patjackson52

lib-threadsafe/src/jvmTest/kotlin/org/reduxkotlin/util/CreateThreadSafeStoreSpec.kt

@@ -1,14 +1,14 @@
 package org.reduxkotlin.util
 
 import kotlinx.coroutines.*
-import org.reduxkotlin.*
+import org.reduxkotlin.createThreadSafeStore
 import org.spekframework.spek2.Spek
 import org.spekframework.spek2.style.specification.describe
 import kotlin.system.measureTimeMillis
-import kotlin.test.*
+import kotlin.test.assertEquals
 
-object CreateThreadSafeStoreSpec : Spek({
-    describe("createThreadSafeStore") {
+object MultiThreadedSpec : Spek({
+    describe("createStore") {
         it("multithreaded increments massively") {
             suspend fun massiveRun(action: suspend () -> Unit) {
                 val n = 100  // number of coroutines to launch
@@ -26,19 +26,15 @@ object CreateThreadSafeStoreSpec : Spek({
                 println("Completed ${n * k} actions in $time ms")
             }
 
-            val counterContext = newFixedThreadPoolContext(5, "CounterContext")
-
             //NOTE: changing this to createStore() breaks the tests
             val store = createThreadSafeStore(counterReducer, TestCounterState())
             runBlocking {
-                withContext(counterContext) {
+                withContext(Dispatchers.Default) {
                     massiveRun {
                         store.dispatch(Increment())
                     }
                 }
-                withContext(counterContext) {
-                    assertEquals(100000, store.state.counter)
-                }
+                assertEquals(100000, store.state.counter)
             }
         }
     }

lib/src/commonMain/kotlin/org/reduxkotlin/CreateStore.kt

@@ -73,7 +73,10 @@ fun <State> createStore(
             """|You may not call store.getState() while the reducer is executing.
              |The reducer has already received the state as an argument.
              |Pass it down from the top reducer instead of reading it from the 
-             |store.""".trimMargin()
+             |store.
+             |You may be accessing getState while dispatching from another
+             |thread.  Try createThreadSafeStore().
+             |https://reduxkotlin.org/introduction/threading""".trimMargin()
         }
 
         return currentState
@@ -111,7 +114,10 @@ fun <State> createStore(
              |subscribe from a component and invoke store.getState() in the 
              |callback to access the latest state. See 
              |https://www.reduxkotlin.org/api/store#subscribelistener-storesubscriber
-             |for more details.""".trimMargin()
+             |for more details.
+             |You may be seeing this due accessing the store from multiplethreads.
+             |Try createThreadSafeStore()
+             |https://reduxkotlin.org/introduction/threading""".trimMargin()
         }
 
         var isSubscribed = true
@@ -169,10 +175,18 @@ fun <State> createStore(
             |actions.""".trimMargin()
         }
 
+        /*
         check(!isDispatching) {
-            "Reducers may not dispatch actions."
+            """You may not dispatch while state is being reduced.
+            |2 conditions can cause this error:
+            |    1) Dispatching from a reducer
+            |    2) Dispatching from multiple threads
+            |If #2 switch to createThreadSafeStore().
+            |https://reduxkotlin.org/introduction/threading""".trimMargin()
         }
 
+         */
+
         try {
             isDispatching = true
             currentState = currentReducer(currentState, action)