Execution

registerExecutionHandlers — server/socket/handlers/executionHandlers.js

Socket handler for submitting code to the executor and persisting execution results in the database. It depends on EXECUTOR_ADDR for the HTTP call to the execution service and on Prisma for storage.

Server Events

submitCode

Submits a team solution for execution and persistence.

socket.emit("submitCode", {
	roomId: string,
	code: string,
	type: "TWOPLAYER" | "FOURPLAYER",
	team?: "team1" | "team2",
	teamId?: string,
	testCases?: Array<any>,
	runIDs?: Array<any>,
	submitTime?: string | number | Date,
	submitTimer?: string,
});

Field	Type	Required	Description
roomId	string	Yes	Game room ID.
code	string	Effectively yes	Source code submitted by the team. The validator marks it optional, but execution requires it.
type	TWOPLAYER | FOURPLAYER	Yes	Game mode.
team	team1 | team2	Four-player only	Identifies which team submitted.
teamId	string	Optional	Socket room for notifying the submitting team.
testCases	Array<any>	Optional	Fallback game test cases when Redis has none.
runIDs	Array<any>	Optional	Fallback IDs for the test cases.
submitTime	string | number | Date	Optional	Submission timestamp source.
submitTimer	string	Optional	Alternate timestamp string; if blank, the handler falls back to submitTime.

Behavior

1. Validates the payload with Zod.
2. Normalizes submitTime and submitTimer into a persisted timestamp.
3. For TWOPLAYER games:
   1. Loads the current gameResult and gameRoom.
   2. Stores the submitted code in gameResult.team1Code and team1SubmittedAt.
   3. Fetches team-generated test cases from Redis via gameService.getTestCases(team1Id).
   4. Falls back to the event payload if Redis has no test cases.
   5. Loads hidden tests from problemTest and normalizes them.
   6. Calls executeAndPersist(...) once for team 1.
   7. Marks the game finished, emits gameEnded, cleans up timers, removes players from sockets, and deletes the VM.
4. For FOURPLAYER games:
   1. Requires team.
   2. Deduplicates submissions using Redis key game:{roomId}:submissions.
   3. Stores the submitting team's code and timestamp in gameResult.
   4. Waits until both teams have submitted.
   5. Loads team-specific test cases from Redis, falling back to the payload when needed.
   6. Loads hidden tests once and normalizes them.
   7. Executes both teams in parallel with executeAndPersist(...).
   8. If either execution fails, the game is not finalized and an error is emitted.
   9. If both succeed, the game is finished, timers are cleaned up, gameEnded is emitted, sockets are removed, and the VM is deleted.

Errors

Scenario	Result
Invalid payload	Emits error with Invalid payload for submitCode.
Missing roomId	Returns early without emitting a success event.
Missing gameResult or gameRoom	Emits error with Game or result not found.
Missing team in four-player mode	Emits error with Missing team for four-player submitCode.
Executor request failure	Logs the error and emits a generic socket error from the caller.
Persistence failure	Logs the error and emits a generic socket error from the caller.

submitTestCases

Executes arbitrary test cases for the caller and sends back computed outputs.

socket.emit("submitTestCases", {
	roomId: string,
	code: string,
	testCases: Array<any>,
	runIDs: Array<any>,
});

Field	Type	Required	Description
roomId	string	Yes	Game room ID.
code	string	Yes	Source code to execute.
testCases	Array<any>	Yes	Test cases to send to the executor.
runIDs	Array<any>	Yes	Test case IDs passed through to the executor.

Behavior

1. Calls the executor at EXECUTOR_ADDR/execute with language: "javascript".
2. Base64-encodes code before sending it.
3. Returns only the matching results for the provided testCases.
4. Emits receiveTestCaseSync to socket.teamId when available; otherwise emits to the current socket.

Errors

Scenario	Result
Executor request or parsing failure	Emits error with Sorry that didn't work try again in a few seconds.

Helper

async executeAndPersist(params): Promise<{ teamNumber: number, totalTests: number, passedCount: number, executionTimeMs: number[], success: true }>

Internal helper used by submitCode to run the executor and persist results.

Parameter	Type	Description
roomId	string	Game room ID used in the executor payload.
gameResultId	string	Prisma gameResult ID used for persistence.
code	string	Submitted source code.
teamNumber	number	Team being executed, usually 1 or 2.
testCases	Array<any>	Game test cases to execute.
testCaseIds	Array<any>	IDs for the game test cases.
gameRoomId	string	Direct game room reference stored with each gameTest row.
hiddenTestCases	Array<any>	Hidden test cases to append after the game test cases. Defaults to [].
hiddenTestCaseIds	Array<any>	IDs for the hidden test cases. Defaults to [].

Behavior

1. Builds a combined execution list from game and hidden tests.
2. Sends a POST request to ${EXECUTOR_ADDR}/execute.
3. Base64-encodes the code and JSON-stringifies the test cases and run IDs.
4. Parses results from the executor response.
5. Upserts one gameTest row per executed test case.
6. Persists team-specific columns such as team1ActualOutput, team1Passed, team2ActualOutput, and team2Passed depending on teamNumber.
7. Returns aggregate metadata including the number of tests, passed count, and per-test execution times.

Errors

Scenario	Result
Executor HTTP failure	Throws an error.
Prisma transaction failure	Throws an error.

Preconditions

• EXECUTOR_ADDR must point to the execution service.
• The executor must be available before the handler is invoked.
• Database access must be available for persistence.
• The executor can only accept json

Postconditions

• Successful submissions persist gameTest rows for both game and hidden tests.
• Completed games emit gameEnded and are marked finished.
• submitTestCases replies with computed outputs for the requested cases.