logctx.AddField(ctx, key, value) added (#7)

Author: pellared

README.md

@@ -4,7 +4,7 @@ Small, easy to use, yet powerful utility packages for [**logrus**](https://githu
 
 ## `logctx` package [![GoDoc](https://godoc.org/github.com/go-logrusutil/logrusutil/logctx?status.svg)](https://godoc.org/github.com/go-logrusutil/logrusutil/logctx)
 
-Add a log entry to the context using `logctx.New(ctx, logEntry)`. Retrieve the log entry using `logctx.From(ctx)`.
+Add a log entry to the context using `logctx.New(ctx, logEntry)` or simply add a new log field using `logctx.AddField(ctx, key, value)`. Retrieve the log entry using `logctx.From(ctx)`.
 
 ## `errfield` package [![GoDoc](https://godoc.org/github.com/go-logrusutil/logrusutil/errfield?status.svg)](https://godoc.org/github.com/go-logrusutil/logrusutil/errfield)
 

logctx/logctx.go

@@ -25,3 +25,9 @@ func From(ctx context.Context) *logrus.Entry {
 	}
 	return Default
 }
+
+// AddField adds a log field to the contexual log entry.
+func AddField(ctx context.Context, key string, value interface{}) context.Context {
+	entry := From(ctx).WithField(key, value)
+	return New(ctx, entry)
+}

logctx/logctx_test.go

@@ -16,9 +16,12 @@ func Example() {
 	// setting contextual log entry
 	ctx := logctx.New(context.Background(), log.WithField("foo", "bar"))
 
+	// adding additional log field
+	ctx = logctx.AddField(ctx, "bizz", "buzz")
+
 	// retrieving context log entry, adding some data and emitting the log
 	logctx.From(ctx).Info("hello world")
-	// Output: level=info msg="hello world" foo=bar
+	// Output: level=info msg="hello world" bizz=buzz foo=bar
 }
 
 // IMPORTANT: this test is a the end because it alters global Default,