# CoreStoreLogger

    public protocol CoreStoreLogger

Custom loggers should implement the `CoreStoreLogger` protocol and pass its instance to `CoreStoreDefaults.logger`. Calls to `log(...)`, `assert(...)`, and `abort(...)` are not tied to a specific queue/thread, so it is the implementer’s job to handle thread-safety.

- `log(level:message:fileName:lineNumber:functionName:)`

  Handles log messages sent by the `CoreStore` framework.

  #### Declaration

  Swift

      func log(level: LogLevel, message: String, fileName: StaticString, lineNumber: Int, functionName: StaticString)

  #### Parameters

  `level` | the severity of the log message
  `message` | the log message
  `fileName` | the source file name
  `lineNumber` | the source line number
  `functionName` | the source function name

- `log(error:message:fileName:lineNumber:functionName:)`

  Handles errors sent by the `CoreStore` framework.

  #### Declaration

  Swift

      func log(error: CoreStoreError, message: String, fileName: StaticString, lineNumber: Int, functionName: StaticString)

  #### Parameters

  `error` | the error
  `message` | the error message
  `fileName` | the source file name
  `lineNumber` | the source line number
  `functionName` | the source function name

- `assert(_:message:fileName:lineNumber:functionName:)`

  Handles assertions made throughout the `CoreStore` framework.

  #### Declaration

  Swift

      func assert(_ condition: @autoclosure () -> Bool, message: @autoclosure () -> String, fileName: StaticString, lineNumber: Int, functionName: StaticString)

  #### Parameters

  `condition` | the assertion condition
  `message` | the assertion message
  `fileName` | the source file name
  `lineNumber` | the source line number
  `functionName` | the source function name

- `abort(_:fileName:lineNumber:functionName:)` Default implementation

  Handles fatal errors made throughout the `CoreStore` framework. The app wil terminate after this method is called.

  Important

  Implementers may guarantee that the function doesn’t return, either by calling another `Never` function such as `fatalError()` or `abort()`, or by raising an exception. If the implementation does not terminate the app, CoreStore will call an internal `fatalError()` to do so.

  #### Default Implementation

  #### Declaration

  Swift

      func abort(_ message: String, fileName: StaticString, lineNumber: Int, functionName: StaticString)

  #### Parameters

  `message` | the fatal error message
  `fileName` | the source file name
  `lineNumber` | the source line number
  `functionName` | the source function name