Add internal/kctl and internal/config packages with unit tests

internal/config/config.go

@@ -0,0 +1,48 @@
+// Package config loads the user-specific, non-versioned kctl-tui
+// configuration (context pairs, team label key) from a YAML file.
+package config
+
+import (
+	"os"
+	"path/filepath"
+
+	"gopkg.in/yaml.v3"
+
+	"github.com/skoelle/kctl-tui/internal/kctl"
+)
+
+// Config is the root structure of ~/.kctl-tui/config.yaml
+type Config struct {
+	ContextPairs []kctl.ContextPair `yaml:"context_pairs"`
+	TeamLabelKey string              `yaml:"team_label_key"`
+}
+
+// DefaultPath returns the default config file location: ~/.kctl-tui/config.yaml
+func DefaultPath() (string, error) {
+	home, err := os.UserHomeDir()
+	if err != nil {
+		return "", err
+	}
+	return filepath.Join(home, ".kctl-tui", "config.yaml"), nil
+}
+
+// Load reads and parses the config file at path. If the file does not
+// exist, it returns a zero-value Config (no pairs, empty label key) and no
+// error, so the tool can run with sane defaults before the user has set up
+// a config file.
+func Load(path string) (Config, error) {
+	cfg := Config{}
+
+	data, err := os.ReadFile(path)
+	if os.IsNotExist(err) {
+		return cfg, nil
+	}
+	if err != nil {
+		return cfg, err
+	}
+
+	if err := yaml.Unmarshal(data, &cfg); err != nil {
+		return cfg, err
+	}
+	return cfg, nil
+}

internal/config/config_test.go

@@ -0,0 +1,44 @@
+package config
+
+import (
+	"os"
+	"path/filepath"
+	"testing"
+)
+
+func TestLoad_MissingFileReturnsDefaults(t *testing.T) {
+	cfg, err := Load(filepath.Join(t.TempDir(), "does-not-exist.yaml"))
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if len(cfg.ContextPairs) != 0 {
+		t.Fatalf("expected no context pairs, got %v", cfg.ContextPairs)
+	}
+	if cfg.TeamLabelKey != "" {
+		t.Fatalf("expected empty team label key, got %q", cfg.TeamLabelKey)
+	}
+}
+
+func TestLoad_ValidFile(t *testing.T) {
+	content := []byte(`
+context_pairs:
+  - name: "env-pair-1"
+    contexts: ["ctx-a", "ctx-b"]
+team_label_key: "example.org/team"
+`)
+	path := filepath.Join(t.TempDir(), "config.yaml")
+	if err := os.WriteFile(path, content, 0o600); err != nil {
+		t.Fatalf("failed to write test config: %v", err)
+	}
+
+	cfg, err := Load(path)
+	if err != nil {
+		t.Fatalf("unexpected error: %v", err)
+	}
+	if cfg.TeamLabelKey != "example.org/team" {
+		t.Fatalf("unexpected team label key: %q", cfg.TeamLabelKey)
+	}
+	if len(cfg.ContextPairs) != 1 || cfg.ContextPairs[0].Name != "env-pair-1" {
+		t.Fatalf("unexpected context pairs: %v", cfg.ContextPairs)
+	}
+}