more improvements in the test example in PCRE module

NgxExport/Tools/ServiceHookAdaptor.hs

@@ -218,9 +218,8 @@ import           Control.Monad
 -- and therefore the state of /secretWord/ can get altered in the new worker.
 --
 -- To fix this issue in this example, get rid of hook /resetSecretWord/ and use
--- directive /rewrite/.
+-- directive /rewrite/ to process the reset request in location /\/change_sw/.
 --
--- ==== File /nginx.conf/: reset the secret word by /rewrite/
 -- @
 --         location \/reset_sw {
 --             allow 127.0.0.1;
@@ -230,7 +229,17 @@ import           Control.Monad
 --         }
 -- @
 --
--- You may also want to add a proper message for reset in /changeSecretWord/.
+-- You may also want to change the hook message in /changeSecretWord/ to
+-- properly log the reset case.
+--
+-- @
+-- changeSecretWord :: ByteString -> IO L.ByteString
+-- __/changeSecretWord/__ s = do
+--     writeIORef secretWord s
+--     return $ \"The secret word was \" \`L.append\` if B.null s
+--                                                    then \"reset\"
+--                                                    else \"changed\"
+-- @
 
 hookAdaptor :: ByteString -> NgxExportService
 hookAdaptor = ignitionService $

README.md

@@ -1867,9 +1867,7 @@ The order of their execution in a restarted worker process is not defined,
 and therefore the state of *secretWord* can get altered in the new worker.
 
 To fix this issue in this example, get rid of hook *resetSecretWord* and use
-directive *rewrite*.
-
-###### File *nginx.conf*: reset the secret word by *rewrite*
+directive *rewrite* to process the reset request in location */change_sw*.
 
 ```nginx
         location /reset_sw {
@@ -1880,7 +1878,17 @@ directive *rewrite*.
         }
 ```
 
-You may also want to add a proper message for reset in *changeSecretWord*.
+You may also want to change the hook message in *changeSecretWord* to
+properly log the reset case.
+
+```haskell
+changeSecretWord :: ByteString -> IO L.ByteString
+changeSecretWord s = do
+    writeIORef secretWord s
+    return $ "The secret word was " `L.append` if B.null s
+                                                   then "reset"
+                                                   else "changed"
+```
 
 #### Module *NgxExport.Tools.Subrequest*
 

test/ServiceHookAdaptor/test_tools_extra_servicehookadaptor.hs

@@ -35,10 +35,8 @@ ngxExportIOYY 'testSecretWord
 changeSecretWord :: ByteString -> IO L.ByteString
 changeSecretWord s = do
     writeIORef secretWord s
-    return $ L.concat ["The secret word was "
-                      ,if B.null s
-                           then "reset"
-                           else "changed"
-                      ]
+    return $ "The secret word was " `L.append` if B.null s
+                                                   then "reset"
+                                                   else "changed"
 ngxExportServiceHook 'changeSecretWord