From d92a906fcad9c1b4166e1a2e3d7321e19cdeece9 Mon Sep 17 00:00:00 2001
From: Sean <77011910+sean-rn@users.noreply.github.com>
Date: Wed, 11 Aug 2021 20:18:16 -0400
Subject: [PATCH] Allow user configuration of which logger to return from Ctx()
 (#343)

If a user is trying to fetch a logger from their context, they probably
want to log something.  In order to allow returning a useable logger from Ctx()
without breaking backwards compatibilty with the previous behavior, we make it
configurable.
---
 ctx.go      | 5 ++++-
 ctx_test.go | 7 +++++++
 globals.go  | 4 ++++
 3 files changed, 15 insertions(+), 1 deletion(-)

diff --git a/ctx.go b/ctx.go
index ce18a32c..966d17ed 100644
--- a/ctx.go
+++ b/ctx.go
@@ -39,10 +39,13 @@ func (l *Logger) WithContext(ctx context.Context) context.Context {
 }
 
 // Ctx returns the Logger associated with the ctx. If no logger
-// is associated, a disabled logger is returned.
+// is associated, DefaultContextLogger is returned, unless DefaultContextLogger
+// is nil, in which case a disabled logger is returned.
 func Ctx(ctx context.Context) *Logger {
 	if l, ok := ctx.Value(ctxKey{}).(*Logger); ok {
 		return l
+	} else if l = DefaultContextLogger; l != nil {
+		return l
 	}
 	return disabledLogger
 }
diff --git a/ctx_test.go b/ctx_test.go
index 646cd0fb..23558930 100644
--- a/ctx_test.go
+++ b/ctx_test.go
@@ -27,6 +27,13 @@ func TestCtx(t *testing.T) {
 	if log2 != disabledLogger {
 		t.Error("Ctx did not return the expected logger")
 	}
+
+	DefaultContextLogger = &log
+	t.Cleanup(func() { DefaultContextLogger = nil })
+	log2 = Ctx(context.Background())
+	if log2 != &log {
+		t.Error("Ctx did not return the expected logger")
+	}
 }
 
 func TestCtxDisabled(t *testing.T) {
diff --git a/globals.go b/globals.go
index 98c67edb..e561d8f3 100644
--- a/globals.go
+++ b/globals.go
@@ -100,6 +100,10 @@ var (
 	// output. If not set, an error is printed on the stderr. This handler must
 	// be thread safe and non-blocking.
 	ErrorHandler func(err error)
+
+	// DefaultContextLogger is returned from Ctx() if there is no logger associated
+	// with the context.
+	DefaultContextLogger *Logger
 )
 
 var (