Improve docs, add ExecutionIDFrom(ctx) method to Logger

yall.go

@@ -13,13 +13,20 @@ const (
 	MissingExecutionID = "missing_execution_id"
 )
 
+// Logger is the interface of a logger, that has methods to log with a context or without.
+// With is used to decorate the logger with key-value pairs.
+// ExecutionIDFrom allows to extract the execution id from the context, if present, and depends on the concrete logger
+// implementation.
 type Logger interface {
-	contextLogger
-	noContextLogger
+	ContextLogger
+	NoContextLogger
 	With(args ...interface{}) Logger
+	ExecutionIDFrom(ctx context.Context) string
 }
 
-type contextLogger interface {
+// ContextLogger is the interface of a logger, that has methods to log with a context.
+// keysAndValues has to be formed by pairs of key and value, or single Fields.
+type ContextLogger interface {
 	Fatal(ctx context.Context, msg string, keysAndValues ...interface{})
 	Panic(ctx context.Context, msg string, keysAndValues ...interface{})
 	Error(ctx context.Context, msg string, keysAndValues ...interface{})
@@ -28,7 +35,9 @@ type contextLogger interface {
 	Debug(ctx context.Context, msg string, keysAndValues ...interface{})
 }
 
-type noContextLogger interface {
+// NoContextLogger is the interface of a logger, that has methods to log without a context.
+// keysAndValues has to be formed by pairs of key and value, or single Fields.
+type NoContextLogger interface {
 	Fatalnc(msg string, keysAndValues ...interface{})
 	Panicnc(msg string, keysAndValues ...interface{})
 	Errornc(msg string, keysAndValues ...interface{})
@@ -37,6 +46,7 @@ type noContextLogger interface {
 	Debugnc(msg string, keysAndValues ...interface{})
 }
 
+// Field is a loggable object, that can be used instead of key value pairs
 type Field struct {
 	Name  string
 	Value interface{}

zaplogger/zap_logger_test.go

@@ -79,3 +79,12 @@ func TestZapLoggerCreate(t *testing.T) {
 		logger.Info(nil, "test")
 	}
 }
+
+func TestExecutionIDFrom(t *testing.T) {
+	ctx := context.WithValue(context.Background(), yall.ExecutionIDKey, "request_id_test123")
+	logger, _ := zaplogger.NewLogger("test")
+
+	executionID := logger.ExecutionIDFrom(ctx)
+	assert.NotEmpty(t, executionID)
+	assert.EqualValues(t, "request_id_test123", executionID)
+}