feat: add option for injecting additional log fields

go.sum

@@ -8,7 +8,6 @@ github.com/kr/text v0.1.0 h1:45sCR5RtlFHMR4UwH9sdQ5TC8v0qDQCHnXt+kaKSTVE=
 github.com/kr/text v0.1.0/go.mod h1:4Jbv+DJW3UT/LiOwJeYQe1efqtUx/iVham/4vfdArNI=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
-github.com/stretchr/objx v0.1.0 h1:4G4v2dO3VZwixGIRoQ5Lfboy6nUhCyYzaqnIAPPhYs4=
 github.com/stretchr/objx v0.1.0/go.mod h1:HFkY916IF+rwdDfMAkV7OtwuqBVzrE8GR6GFx+wExME=
 github.com/stretchr/objx v0.2.0 h1:Hbg2NidpLE8veEBkEZTL3CvlkUIVzuU9jDplZO54c48=
 github.com/stretchr/objx v0.2.0/go.mod h1:qt09Ya8vawLte6SNmTgCsAVtYtaKzEcn8ATUoHMkEqE=
@@ -18,7 +17,6 @@ github.com/stretchr/testify v1.6.0/go.mod h1:6Fq8oRcR53rry900zMqJjRRixrwX3KX962/
 gopkg.in/check.v1 v0.0.0-20161208181325-20d25e280405/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127 h1:qIbj1fsPNlZgppZ+VLlY7N33q108Sa+fhmuc+sWQYwY=
 gopkg.in/check.v1 v1.0.0-20180628173108-788fd7840127/go.mod h1:Co6ibVJAznAaIkqp8huTwlJQCZ016jof/cbN4VW5Yz0=
-gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c h1:dUUwHk2QECo/6vqA44rthZ8ie2QXMNeKRTHCNY2nXvo=
 gopkg.in/yaml.v3 v3.0.0-20200313102051-9f266ea9e77c/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=
 gopkg.in/yaml.v3 v3.0.0-20200601152816-913338de1bd2 h1:VEmvx0P+GVTgkNu2EdTN988YCZPcD3lo9AoczZpucwc=
 gopkg.in/yaml.v3 v3.0.0-20200601152816-913338de1bd2/go.mod h1:K4uyk7z7BCEPqu6E+C64Yfv1cQ7kz7rIZviUmN+EgEM=

logger.go

@@ -101,11 +101,16 @@ func (l *logger) log(ctx context.Context, lvl Level, msg string, start time.Time
 		return
 	}
 
-	data := map[string]interface{}{
-		l.opt.timeFieldname:     l.opt.timeFormat.format(time.Now()),
-		l.opt.durationFieldname: l.opt.durationUnit.format(time.Since(start)),
+	data := make(map[string]interface{})
+
+	// set the user-defined fields first so they don't clobber any internal fields
+	for k, v := range l.opt.additionalFields {
+		data[k] = v
 	}
 
+	data[l.opt.timeFieldname] = l.opt.timeFormat.format(time.Now())
+	data[l.opt.durationFieldname] = l.opt.durationUnit.format(time.Since(start))
+
 	if l.opt.includeStartTime {
 		data[l.opt.startTimeFieldname] = l.opt.timeFormat.format(start)
 	}

logger_test.go

@@ -177,6 +177,48 @@ func TestLogInternalWithData(t *testing.T) {
 	bl.Reset()
 }
 
+func TestLogWithAdditionalField(t *testing.T) {
+	cfg := &options{}
+	setDefaultOptions(cfg)
+	WithAdditionalField("hello", "world")(cfg)
+	bl := &bufferTestLogger{}
+	l := &logger{opt: cfg, logger: bl}
+	l.log(context.TODO(), LevelInfo, "msg", time.Now(), nil, l.withQuery("query"))
+
+	var content bufLog
+	err := json.Unmarshal(bl.Bytes(), &content)
+	assert.NoError(t, err)
+	assert.Contains(t, content.Data, cfg.timeFieldname)
+	assert.Contains(t, content.Data, cfg.durationFieldname)
+	assert.Contains(t, content.Data, cfg.sqlQueryFieldname)
+	assert.Equal(t, LevelInfo.String(), content.Level)
+	assert.Equal(t, "msg", content.Message)
+	assert.Equal(t, "query", content.Data[cfg.sqlQueryFieldname])
+	assert.Equal(t, "world", content.Data["hello"])
+	bl.Reset()
+}
+
+func TestLogWithAdditionalFields(t *testing.T) {
+	cfg := &options{}
+	setDefaultOptions(cfg)
+	WithAdditionalFields(map[string]interface{}{"hello": "world"})(cfg)
+	bl := &bufferTestLogger{}
+	l := &logger{opt: cfg, logger: bl}
+	l.log(context.TODO(), LevelInfo, "msg", time.Now(), nil, l.withQuery("query"))
+
+	var content bufLog
+	err := json.Unmarshal(bl.Bytes(), &content)
+	assert.NoError(t, err)
+	assert.Contains(t, content.Data, cfg.timeFieldname)
+	assert.Contains(t, content.Data, cfg.durationFieldname)
+	assert.Contains(t, content.Data, cfg.sqlQueryFieldname)
+	assert.Equal(t, LevelInfo.String(), content.Level)
+	assert.Equal(t, "msg", content.Message)
+	assert.Equal(t, "query", content.Data[cfg.sqlQueryFieldname])
+	assert.Equal(t, "world", content.Data["hello"])
+	bl.Reset()
+}
+
 func TestLogInternalErrorLevel(t *testing.T) {
 	cfg := &options{}
 	setDefaultOptions(cfg)

options.go

@@ -18,6 +18,7 @@ type options struct {
 	stmtIDFieldname    string
 	connIDFieldname    string
 	txIDFieldname      string
+	additionalFields   map[string]interface{}
 	sqlQueryAsMsg      bool
 	logArgs            bool
 	logDriverErrSkip   bool
@@ -44,6 +45,7 @@ func setDefaultOptions(opt *options) {
 	opt.stmtIDFieldname = "stmt_id"
 	opt.connIDFieldname = "conn_id"
 	opt.txIDFieldname = "tx_id"
+	opt.additionalFields = make(map[string]interface{})
 	opt.sqlQueryAsMsg = false
 	opt.minimumLogLevel = LevelDebug
 	opt.logArgs = true
@@ -331,6 +333,28 @@ func WithTransactionIDFieldname(name string) Option {
 	}
 }
 
+// WithAdditionalFields allows injecting multiple log fields.
+//
+// In the event of another log field name colliding with any additional fields,
+// it will be overwritten by what comes later.
+func WithAdditionalFields(fields map[string]interface{}) Option {
+	return func(opt *options) {
+		for k, v := range fields {
+			opt.additionalFields[k] = v
+		}
+	}
+}
+
+// WithAdditionalField allows injecting a single log field.
+//
+// In the event of another log field name colliding with any additional fields,
+// it will be overwritten by what comes later.
+func WithAdditionalField(name string, value interface{}) Option {
+	return func(opt *options) {
+		opt.additionalFields[name] = value
+	}
+}
+
 // WithWrapResult set flag to wrap Queryer(Context) and Execer(Context) driver.Rows/driver.Result response.
 //
 // When set to false, result returned from db (driver.Rows/driver.Result object),

options_test.go

@@ -176,6 +176,18 @@ func TestWithTransactionIDFieldname(t *testing.T) {
 	assert.Equal(t, "trxid", cfg.txIDFieldname)
 }
 
+func TestWithAdditionalFields(t *testing.T) {
+	cfg := &options{}
+	setDefaultOptions(cfg)
+
+	WithAdditionalFields(map[string]interface{}{"hello": "world"})(cfg)
+	assert.EqualValues(t, map[string]interface{}{"hello": "world"}, cfg.additionalFields)
+
+	// additional calls should merge
+	WithAdditionalFields(map[string]interface{}{"foo": "bar", "hello": "baz"})(cfg)
+	assert.EqualValues(t, map[string]interface{}{"hello": "baz", "foo": "bar"}, cfg.additionalFields)
+}
+
 func TestWithWrapResult(t *testing.T) {
 	cfg := &options{}
 	setDefaultOptions(cfg)