Adding test coverage for init logger

internal/logging/logging.go

@@ -3,7 +3,6 @@ package logging
 import (
 	"io"
 	"log/slog"
-	"os"
 	"strings"
 )
 
@@ -30,7 +29,7 @@ func InitLogging(level string, w io.Writer, addSource bool) *slog.Logger {
 	// output. Stderr also have greater likely hood of being seen if a programs
 	// output is being redirected.
 	parsedLogLevel := parseLogLevel(level)
-	loggerHandler := slog.NewJSONHandler(os.Stderr, &slog.HandlerOptions{Level: parsedLogLevel, AddSource: addSource})
+	loggerHandler := slog.NewJSONHandler(w, &slog.HandlerOptions{Level: parsedLogLevel, AddSource: addSource})
 	logger := slog.New(loggerHandler)
 	slog.SetDefault(logger)
 	return logger

internal/logging/logging_test.go

@@ -0,0 +1,68 @@
+package logging
+
+import (
+	"bytes"
+	"log/slog"
+	"strings"
+	"testing"
+)
+
+func TestParseLevel(t *testing.T) {
+
+	testTable := []struct {
+		name  string
+		level string
+		want  slog.Level
+	}{
+		{
+			name:  "Default",
+			level: "",
+			want:  slog.LevelInfo,
+		},
+		{
+			name:  "Lowercase",
+			level: "debug",
+			want:  slog.LevelDebug,
+		},
+		{
+			name:  "Mixed case",
+			level: "wArN",
+			want:  slog.LevelWarn,
+		},
+		{
+			name:  "Calitalized",
+			level: "ERROR",
+			want:  slog.LevelError,
+		},
+		{
+			name:  "Info level",
+			level: "info",
+			want:  slog.LevelInfo,
+		},
+	}
+
+	for _, test := range testTable {
+		t.Run(test.name, func(t *testing.T) {
+			got := parseLogLevel(test.level)
+
+			if got != test.want {
+				t.Errorf("got %s, want %s", got, test.want)
+			}
+		})
+	}
+
+}
+
+func TestInitLogging(t *testing.T) {
+	spy := bytes.Buffer{}
+	msg := "Observability"
+
+	logger := InitLogging("info", &spy, false)
+	logger.Info(msg)
+
+	content := spy.String()
+	if !strings.Contains(content, msg) {
+		t.Fatalf("Error comparing messages. Wanted: %q got: %q", msg, content)
+	}
+
+}