Revised README, also add EOL at end of file

Author: Jiaxin Fan

tests/src/test/standalone/README.md

@@ -26,32 +26,63 @@ The following example shows how to generate a Docker image for the Node.js 18 ru
 ```
 ./gradlew core:nodejs18Action:distDocker
 ```
-This will return the following runtime image with the name `action-nodejs-v18`
+This will return the following runtime image with the name `action-nodejs-v18`, which should be listed after using the `docker images`
 
 ## Running the Container
-For the purpose of the test. We are going to access the the runner container via `localhost`.
-The `Action` container exposes `port 8080` (see the Dockerfile for the associated Docker image), thus we publish the container's `port 8080` to the `localhost`:
+For the purpose of the test. We are going to start the container with a web service running inside it built with Node/Express. In order to access this servicec within the container from the outside, as we are about to do using `curl`, port mapping is done next. By doing so, we access the web service inside docker by first reaching an IP port on `localhost`, which subsequently forwards the request to the docker container's designated port.
+In our example, the `Action` container exposes `port 8080` (see the Dockerfile for the associated Docker image), thus we publish the container's `port 8080` to the `localhost` (here, `port 3008` on `localhost` is chosen arbitrarily, as long as the port is not already assigned):
 ```
 docker run --publish 3008:8080 -i -t action-nodejs-v18:latest
 ```
+A simpler way is to map `port 80` on `localhost` to the container's `port 8080`. The port number assigned to the HTTP protocol is `80` Since we will be sending actions against the runtime using HTTP, using this number will allow us to omit the port in the request later. In case `port 80` is already assigned, resort to the method above.
 
 ## Testing
 This example has prepared a `helloworld.json` file to post using `curl`.
+```json
+{
+  "value": {
+    "name" : "nodejs-helloworld",
+    "main" : "main",
+    "binary": false,
+    "code" : "function main() {return {payload: 'Hello World!'};}"
+  } 
+}
+```
+The json file contains a simple JavaScript function, which is the actual payload.
 
 ### Initialze the Runtime
-Initialize the runtime with by invoking the ```/init``` endpoint.
+Before issuing the action against the runtime, we first initialize the function with by invoking the ```/init``` endpoint.
 ```
 curl -H "Content-Type:application/json" -X POST --data '@openwhisk-runtime-nodejs/tests/src/test/standalone/helloworld/helloworld.json' http://localhost:3008/init
 
 {"OK":true}
 ```
+being the expected response.
+
+As mentioned above, if `port 80` on `localhost` was used, the command could simply be ```
+curl -H "Content-Type:application/json" -X POST --data '@openwhisk-runtime-nodejs/tests/src/test/standalone/helloworld/helloworld.json' http://localhost/init
+```
 
 #### Run the function
 
-Execute the function using the ```/run``` endpoint.
+Invoke the function using the ```/run``` endpoint.
 
 ```
 curl -H ""Content-Type:application/json" -X POST --data '@openwhisk-runtime-nodejs/tests/src/test/standalone/helloworld/helloworld.json' http://localhost:3008/run
+```
 
+The JavaScript function in this example is one without arguments. Using the same json file as during initialization won't be a problem. Strictly speaking, we should have provided another json file with the arguments. In our case, it should simply be
+```json
+{
+   "value": {}
+}
+```
+The expected response should be
+```
 {"payload":"Hello World!"}
-```
+```
+Also the running container will print
+```
+XXX_THE_END_OF_A_WHISK_ACTIVATION_XXX
+```
+in the terminal