From 32acd713045e4880540d74b98ebf7224c484656d Mon Sep 17 00:00:00 2001
From: Mark Sagi-Kazar <mark.sagikazar@gmail.com>
Date: Thu, 9 Dec 2021 13:34:40 -0400
Subject: [PATCH] feat: add logger interface and default implementation
---
logger.go | 77 +++++++++++++++++++++++++++++++++++++++++++++++++++++++
1 file changed, 77 insertions(+)
create mode 100644 logger.go
diff --git a/logger.go b/logger.go
new file mode 100644
index 0000000..0115067
--- /dev/null
+++ b/logger.go
@@ -0,0 +1,77 @@
+package viper
+
+import (
+ "fmt"
+
+ jww "github.com/spf13/jwalterweatherman"
+)
+
+// Logger is a unified interface for various logging use cases and practices, including:
+// - leveled logging
+// - structured logging
+type Logger interface {
+ // Trace logs a Trace event.
+ //
+ // Even more fine-grained information than Debug events.
+ // Loggers not supporting this level should fall back to Debug.
+ Trace(msg string, keyvals ...interface{})
+
+ // Debug logs a Debug event.
+ //
+ // A verbose series of information events.
+ // They are useful when debugging the system.
+ Debug(msg string, keyvals ...interface{})
+
+ // Info logs an Info event.
+ //
+ // General information about what's happening inside the system.
+ Info(msg string, keyvals ...interface{})
+
+ // Warn logs a Warn(ing) event.
+ //
+ // Non-critical events that should be looked at.
+ Warn(msg string, keyvals ...interface{})
+
+ // Error logs an Error event.
+ //
+ // Critical events that require immediate attention.
+ // Loggers commonly provide Fatal and Panic levels above Error level,
+ // but exiting and panicing is out of scope for a logging library.
+ Error(msg string, keyvals ...interface{})
+}
+
+type jwwLogger struct{}
+
+func (jwwLogger) Trace(msg string, keyvals ...interface{}) {
+ jww.TRACE.Printf(jwwLogMessage(msg, keyvals...))
+}
+
+func (jwwLogger) Debug(msg string, keyvals ...interface{}) {
+ jww.DEBUG.Printf(jwwLogMessage(msg, keyvals...))
+}
+
+func (jwwLogger) Info(msg string, keyvals ...interface{}) {
+ jww.INFO.Printf(jwwLogMessage(msg, keyvals...))
+}
+
+func (jwwLogger) Warn(msg string, keyvals ...interface{}) {
+ jww.WARN.Printf(jwwLogMessage(msg, keyvals...))
+}
+
+func (jwwLogger) Error(msg string, keyvals ...interface{}) {
+ jww.ERROR.Printf(jwwLogMessage(msg, keyvals...))
+}
+
+func jwwLogMessage(msg string, keyvals ...interface{}) string {
+ out := msg
+
+ if len(keyvals) > 0 && len(keyvals)%2 == 1 {
+ keyvals = append(keyvals, nil)
+ }
+
+ for i := 0; i <= len(keyvals)-2; i += 2 {
+ out = fmt.Sprintf("%s %v=%v", out, keyvals[i], keyvals[i+1])
+ }
+
+ return out
+}