config updated to improve setting values, writing changes and test coverage

internal/config/print_test.go

@@ -0,0 +1,129 @@
+package config
+
+import (
+	"encoding/json"
+	"log/slog"
+	"os"
+	"path/filepath"
+	"slices"
+	"strings"
+	"testing"
+
+	"go.yaml.in/yaml/v3"
+)
+
+// captureStdout returns what fn prints to os.Stdout.
+func captureStdout(t *testing.T, fn func()) string {
+	t.Helper()
+	path := filepath.Join(t.TempDir(), "stdout")
+	f, err := os.Create(filepath.Clean(path))
+	if err != nil {
+		t.Fatal(err)
+	}
+	old := os.Stdout
+	os.Stdout = f
+	fn()
+	os.Stdout = old
+	if err := f.Close(); err != nil {
+		t.Fatal(err)
+	}
+	b, err := os.ReadFile(filepath.Clean(path))
+	if err != nil {
+		t.Fatal(err)
+	}
+	return string(b)
+}
+
+func TestPrintTerminal(t *testing.T) {
+	conf := defaultConfig(t)
+	got := captureStdout(t, conf.PrintTerminal)
+	if want := conf.String() + "\n"; got != want {
+		t.Errorf("PrintTerminal printed %q; want %q", got, want)
+	}
+}
+
+// String lists every key once, sorted, so the output is the same each run.
+func TestStringSorted(t *testing.T) {
+	conf := defaultConfig(t)
+	var keys []string
+	for _, line := range strings.Split(strings.TrimSpace(conf.String()), "\n") {
+		key, _, _ := strings.Cut(line, " = ")
+		keys = append(keys, key)
+	}
+	if !slices.IsSorted(keys) || len(keys) != len(conf.Flatten()) {
+		t.Errorf("String keys = %v; want each key once, sorted", keys)
+	}
+	if first := conf.String(); conf.String() != first {
+		t.Error("String output differs between calls")
+	}
+}
+
+func TestPrintJson(t *testing.T) {
+	conf := defaultConfig(t)
+	out := captureStdout(t, conf.PrintJson)
+	var m map[string]any
+	if err := json.Unmarshal([]byte(out), &m); err != nil {
+		t.Fatalf("PrintJson output is not JSON: %v\n%s", err, out)
+	}
+	if got := m["logging"].(map[string]any)["level"]; got != "warn" {
+		t.Errorf("logging.level = %v; want warn", got)
+	}
+}
+
+func TestPrintYaml(t *testing.T) {
+	conf := defaultConfig(t)
+	out := captureStdout(t, conf.PrintYaml)
+	var m map[string]any
+	if err := yaml.Unmarshal([]byte(out), &m); err != nil {
+		t.Fatalf("PrintYaml output is not YAML: %v\n%s", err, out)
+	}
+	if got := m["logging"].(map[string]any)["level"]; got != "warn" {
+		t.Errorf("logging.level = %v; want warn", got)
+	}
+}
+
+// PrintLog logs one line per key, at the level asked for (info for any
+// level other than debug, warn and error).
+func TestPrintLog(t *testing.T) {
+	conf := defaultConfig(t)
+	for _, tt := range []struct {
+		at   slog.Level
+		want string
+	}{
+		{slog.LevelDebug, "level=DEBUG"},
+		{slog.LevelInfo, "level=INFO"},
+		{slog.LevelWarn, "level=WARN"},
+		{slog.LevelError, "level=ERROR"},
+		{slog.LevelError + 4, "level=INFO"},
+	} {
+		logs := captureLogs(t, slog.LevelDebug)
+		conf.PrintLog(tt.at)
+
+		lines := strings.Split(strings.TrimSpace(logs.String()), "\n")
+		if len(lines) != len(conf.Flatten()) {
+			t.Errorf("PrintLog(%v) logged %d lines; want %d", tt.at, len(lines), len(conf.Flatten()))
+		}
+		for _, l := range lines {
+			if !strings.Contains(l, tt.want) {
+				t.Errorf("PrintLog(%v) line %q; want %s", tt.at, l, tt.want)
+			}
+		}
+		if !strings.Contains(logs.String(), "logging.level = warn") {
+			t.Errorf("PrintLog(%v) missing logging.level:\n%s", tt.at, logs)
+		}
+		// Each line is msg="\t<key> = <value>".
+		flat := conf.Flatten()
+		var keys []string
+		for _, l := range lines {
+			_, msg, _ := strings.Cut(l, `msg="\t`)
+			key, _, _ := strings.Cut(msg, " = ")
+			if _, ok := flat[key]; !ok {
+				t.Errorf("PrintLog(%v) line %q: no key", tt.at, l)
+			}
+			keys = append(keys, key)
+		}
+		if !slices.IsSorted(keys) {
+			t.Errorf("PrintLog(%v) keys not sorted: %v", tt.at, keys)
+		}
+	}
+}