Stores breakage (regression?) with more advanced JS.

[cooperaj]

I'm running some mock code that looks like

const codeData = ... array of objects ...
const store = stores.open('codeData');

for (let code of codeData) {
  logger.debug('Processing code data ' + code.code);
  if (store.hasItemWithKey(code.code)) {
    logger.debug('Attempting to load altered code ' + code.code);
    let loadedCode = store.load(code.code)
    logger.debug('Found altered code ' + loadedCode.code);
    codes.push(loadedCode)
  } else {
    codes.push(code);
    logger.debug('Using seeded code ' + code.code);
  }
}

It's essentially merging changed data with our initially defined fixtures.

My issue is that it doesn't work and fails with an exception that looks like (lots more stacktrace but none really helpful)

Caused by: org.graalvm.polyglot.PolyglotException: The Context is already closed.
 	at com.oracle.truffle.polyglot.PolyglotEngineException.closedException(PolyglotEngineException.java:139) ~[truffle-api-22.3.5.jar:?]
 	at com.oracle.truffle.polyglot.PolyglotContextImpl.checkClosedOrDisposing(PolyglotContextImpl.java:1257) ~[truffle-api-22.3.5.jar:?]
 	at com.oracle.truffle.polyglot.PolyglotContextImpl.enterThreadChanged(PolyglotContextImpl.java:808) ~[truffle-api-22.3.5.jar:?]
 	at com.oracle.truffle.polyglot.PolyglotEngineImpl.enterCached(PolyglotEngineImpl.java:2026) ~[truffle-api-22.3.5.jar:?]
 	at com.oracle.truffle.polyglot.HostToGuestRootNode.execute(HostToGuestRootNode.java:109) ~[truffle-api-22.3.5.jar:?]
 	at com.oracle.truffle.polyglot.PolyglotMap.containsKey(PolyglotMap.java:115) ~[truffle-api-22.3.5.jar:?]
 	at io.gatehill.imposter.scripting.graalvm.proxy.InterceptingMap.hasMember(InterceptingMap.kt:64) ~[imposter-scripting-graalvm-4.7.0.jar:?]
 	at <js>.loadCodes(Unnamed:99) ~[?:?]
 	at <js>.getCode(Unnamed:110) ~[?:?]
 	at <js>.revokeCode(Unnamed:119) ~[?:?]
 	at <js>.:=>(Unnamed:162) ~[?:?]
 	at <js>.__run(Unnamed:33) ~[?:?]

Just prior to the exception the logs read.

16:15:40 INFO  s./opt/imposter/config/mock-responses - Operation is api.resources.revoke_route
16:15:40 DEBUG s./opt/imposter/config/mock-responses - Processing code data NYGUAMNB46JQ
216:15:40 DEBUG s./opt/imposter/config/mock-responses - Attempting to load altered code NYGUAMNB46JQ

From this I think you can see that the failure is happening on the store.load line - which should only be hit if hasItemWithKey has returned true. hasItemWithKey is a function which I think is working as unless other code in the file is hit to call a store.save the else part of the if statement is processed - I get expected results and the log entry Using seeded code NYGUAMNB46JQ. I can also verify this is the broken line as removing it allows the code to work.

In summary

1. Opening a store doesn't appear to cause an error.
2. Saving to a store doesn't cause an error and, in fact, makes hasItemWithKey return true.
3. Loading all from the same store will return empty '{}' - even if a save operation has occured.
4. Loading the item with the verified as saved key causes a Polyglot Exception.

Version: 4.7.0 Docker.

[cooperaj]

I've discovered that if I add store.save(code.code, code) to the loop then it doesn't error (but then would presumably overwrite any legitimately stored values.

Something like

const codeData = ... array of objects ...
const store = stores.open('codeData');

for (let code of codeData) {
  store.save(code.code, code)
  logger.debug('Processing code data ' + code.code);
  if (store.hasItemWithKey(code.code)) {
    logger.debug('Attempting to load altered code ' + code.code);
    let loadedCode = store.load(code.code)
    logger.debug('Found altered code ' + loadedCode.code);
    codes.push(loadedCode)
  } else {
    codes.push(code);
    logger.debug('Using seeded code ' + code.code);
  }
}

This tells me that perhaps it's not actually saving anything between requests?

[cooperaj]

Current workaround

It appears that maybe the store is unable to contain objects. Storing and retrieving items as JSON allows the store to work.

[outofcoffee]

Hi @cooperaj - thank you for raising this. We'll take a look 👍