Fuchs_Intranet/.github/instructions/logging.instructions.md

applyTo

applyTo
Fuchs/**,Fuchs_DataService/**,MFR_RESTClient/**,MT940Parser/**

Logging Instructions

Overview

All logging in this solution uses Microsoft.Extensions.Logging.ILogger<T>. Never use System.Diagnostics.Debug.Print, Debug.WriteLine, Console.WriteLine, or OCMS.ocms_debug.debug_log in business or library code.

Providers

Fuchs_DataService — FdsLoggerProvider

• Location: Fuchs_DataService/Logging/FdsLoggerProvider.cs
• Always active: Debug output (System.Diagnostics.Debug.WriteLine) + file (tmp/DebugLog.txt, tmp/ErrorLog.txt)
• Database logging: prepared via WriteToDatabase() but disabled by default. Activate with FdsLoggerProvider.DatabaseLoggingEnabled = true.
• Registered in FdsMain.cs via LoggerFactory.Create(b => b.SetMinimumLevel(LogLevel.Debug).AddFdsLogging()).

Fuchs — FuchsLoggerProvider

• Location: Fuchs/Logging/FuchsLoggerProvider.cs
• Always active: Debug output + file (logs/AppLog.txt, logs/ErrorLog.txt)
• Database logging: prepared but disabled by default. Activate with FuchsLoggerProvider.DatabaseLoggingEnabled = true.
• Registered in Program.cs via builder.Logging.SetMinimumLevel(LogLevel.Debug).AddFuchsLogging().

MFR_RESTClient — Library (no provider)

• No logging provider — purely a library.
• MFRClient accepts ILogger<MFRClient>? as an optional constructor parameter.
• Defaults to NullLogger<MFRClient>.Instance when no logger is provided.
• Callers supply a logger from the host's ILoggerFactory.

MT940Parser — Library (no provider)

• Location: ../../WebProjectComponents/MT940Parser/ (shared external component)
• No logging provider — purely a library.
• Public entry point only: Parser accepts ILogger<Parser>? as an optional constructor parameter and defaults to NullLogger<Parser>.Instance.
• Internal sub-parsers (StatementParser, BalanceParser, StatementLineParser, AdditionalInfoParser) are pure algorithmic classes. They do not hold logger fields. Parse errors are thrown as exceptions (InvalidDataException, FormatException) and caught by Parser.Parse(), which logs them at LogWarning.
• Callers supply a logger when constructing Parser; the sub-parsers never need one directly.

Rules

• DI classes (singletons, scoped): receive ILogger<T> via constructor injection.
• Library classes (MFRClient, Parser): accept ILogger<T>? as an optional constructor parameter, default to NullLogger<T>.Instance.
• Internal library helpers (StatementParser, BalanceParser, StatementLineParser, AdditionalInfoParser): pure algorithmic, no logger field. Throw exceptions; the public entry-point catches and logs.
• Static helpers (FdsShared, Banking): accept ILogger? as an optional method parameter, or delegate to FdsDebug.DebugLog for infrastructure-level errors.
• FdsDebug remains the fallback for static infrastructure code only (stream helpers, etc.). Do not use it in new class-level code.
• Use structured logging parameters: _logger.LogError(ex, "Message {Param}", value) — never string interpolation in the message template.

Log Levels

Level	Use for
LogDebug	Timing, row counts, progress traces
LogInformation	Service start/stop, significant state changes
LogWarning	Recoverable issues, skipped items
LogError	Caught exceptions, data sync failures
LogCritical	Unrecoverable failures that stop a job

Enabling Database Logging

// Fuchs_DataService
FdsLoggerProvider.DatabaseLoggingEnabled = true;

// Fuchs web
FuchsLoggerProvider.DatabaseLoggingEnabled = true;

Uncomment the body of WriteToDatabase() in the respective provider and adjust the stored procedure name.