Understanding Effect.try Return Types in Programming

// I have the following util:
export function safeJsonParse(
  value: string,
  errorMessage: string = 'Something went wrong during JSON data parsing',
): Effect.Effect<unknown, JsonParseError, never> {
  return Effect.try({
    try: () => JSON.parse(value),
    catch: () => new JsonParseError({ message: errorMessage }),
  })
}

// I am trying to write some simple unit tests (I am using vitest)
expect(safeJsonParse('"duck"')).toStrictEqual(Effect.succeed('duck'))
expect(safeJsonParse('null')).toStrictEqual(Effect.succeed(null))
expect(safeJsonParse('undefined')).toStrictEqual(Effect.succeed(undefined))

expect(safeJsonParse('"duck"').pipe(Effect.runSyncExit)).toStrictEqual(Effect.succeed('duck'))