code cleanup as per review

Author: jharris4

src/shared/modules/connections/connectionsDuck.ts

@@ -121,6 +121,10 @@ export function getConnection(
   )
 }
 
+export function getLastUseDb(state: GlobalState): string | null {
+  return (state[NAME] || {}).lastUseDb
+}
+
 export function getUseDb(state: GlobalState): string | null {
   return (state[NAME] || {}).useDb
 }
@@ -288,7 +292,7 @@ export default function(state = initialState, action: any) {
     case UPDATE_AUTH_ENABLED:
       return updateAuthEnabledHelper(state, action.authEnabled)
     case USE_DB:
-      const useDb = getActionUseDb(action, state)
+      const { useDb } = action
       let lastUseDb = useDb
       if (useDb === null) {
         lastUseDb = state.useDb || state.lastUseDb
@@ -365,30 +369,12 @@ export const useDb = (db: any = null) => ({ type: USE_DB, useDb: db })
 
 export const resetUseDb = () => ({ type: USE_DB, useDb: null })
 
-export const useDefaultDb = (db: any, databases: any) => ({
-  type: USE_DB,
-  useDb: db,
-  databases
-})
-
-const getActionUseDb = (action: any, state: any) => {
-  const { databases } = action
-  let { useDb } = action
-  if (useDb && databases) {
-    const { lastUseDb } = state
-    if (lastUseDb && databases.some((db: any) => db.name === lastUseDb)) {
-      useDb = lastUseDb
-    }
-  }
-  return useDb
-}
-
 // Epics
-export const useDbEpic = (action$: any, store: any) => {
+export const useDbEpic = (action$: any) => {
   return action$
     .ofType(USE_DB)
     .do((action: any) => {
-      bolt.useDb(getActionUseDb(action, store.getState()[NAME]))
+      bolt.useDb(action.useDb)
     })
     .map((action: any) => {
       if (!action.useDb) {

src/shared/modules/dbMeta/dbMetaDuck.ts

@@ -34,8 +34,8 @@ import {
   setAuthEnabled,
   onLostConnection,
   getUseDb,
+  getLastUseDb,
   useDb,
-  useDefaultDb,
   getActiveConnectionData,
   updateConnection
 } from 'shared/modules/connections/connectionsDuck'
@@ -50,7 +50,7 @@ import {
   getDbClusterRole
 } from '../features/versionedFeatures'
 import { extractServerInfo } from './dbMeta.utils'
-import { assign, reduce } from 'lodash-es'
+import { assign, last, reduce } from 'lodash-es'
 import {
   hasClientConfig,
   updateUserCapability,
@@ -453,10 +453,15 @@ const switchToRequestedDb = (store: any) => {
   const activeConnection = getActiveConnectionData(store.getState())
   const requestedUseDb = activeConnection?.requestedUseDb
 
-  const switchToDefaultDb = () => {
-    const defaultDb = databases.find((db: any) => db.default)
-    if (defaultDb) {
-      store.dispatch(useDefaultDb(defaultDb.name, databases))
+  const switchToLastUsedOrDefaultDb = () => {
+    const lastUsedDb = getLastUseDb(store.getState())
+    if (lastUsedDb && databases.some((db: any) => db.name === lastUsedDb)) {
+      store.dispatch(useDb(lastUsedDb))
+    } else {
+      const defaultDb = databases.find((db: any) => db.default)
+      if (defaultDb) {
+        store.dispatch(useDb(defaultDb.name))
+      }
     }
   }
 
@@ -479,10 +484,10 @@ const switchToRequestedDb = (store: any) => {
       store.dispatch(executeCommand(`:use ${requestedUseDb}`), {
         source: commandSources.auto
       })
-      switchToDefaultDb()
+      switchToLastUsedOrDefaultDb()
     }
   } else {
-    switchToDefaultDb()
+    switchToLastUsedOrDefaultDb()
   }
   return Rx.Observable.of(null)
 }