Phase 5-7: README, Makefile, unit tests

- README.md: full usage docs
- Makefile: build/install/uninstall/test/lint/clean targets
- config/config_test.go: 7 tests (load, save, find, add, roundtrip, invalid yaml)
- runtime/runtime_test.go: 6 tests (get, available, ListRunning graceful degradation)
- systemd/generator_test.go: 7 tests (ServiceName, Generate system/user/custom/docker/unknown, buildExecCommands)
- fix: docker/podman ListRunning returns nil (not error) when daemon unavailable
- fix: invalid YAML test uses tab-indent which is genuinely unparseable

systemd/generator_test.go

@@ -0,0 +1,179 @@
+package systemd
+
+import (
+	"strings"
+	"testing"
+
+	"github.com/warkanum/unitdore/config"
+)
+
+func TestServiceName(t *testing.T) {
+	u := config.Unit{Name: "nginx"}
+	got := ServiceName(u)
+	want := "unitdore-nginx.service"
+	if got != want {
+		t.Errorf("ServiceName() = %q, want %q", got, want)
+	}
+}
+
+func TestGenerate_SystemUnit(t *testing.T) {
+	u := config.Unit{
+		Name:    "nginx",
+		Runtime: "podman",
+		Order:   1,
+		Enabled: true,
+	}
+
+	content, err := Generate(u)
+	if err != nil {
+		t.Fatalf("Generate() error: %v", err)
+	}
+
+	checks := []string{
+		"[Unit]",
+		"[Service]",
+		"[Install]",
+		"unitdore-nginx.service",
+		"Description=Unitdore: nginx (podman)",
+		"After=network.target",
+		"WantedBy=multi-user.target",
+		"ExecStart=/usr/bin/podman start -a nginx",
+		"ExecStop=/usr/bin/podman stop nginx",
+		"Restart=on-failure",
+		"Generated by unitdore",
+	}
+
+	for _, check := range checks {
+		if !strings.Contains(content, check) {
+			t.Errorf("Generate() missing %q in output:\n%s", check, content)
+		}
+	}
+}
+
+func TestGenerate_UserUnit(t *testing.T) {
+	u := config.Unit{
+		Name:    "myapp",
+		Runtime: "docker",
+		User:    "hein",
+		Order:   2,
+		Enabled: true,
+	}
+
+	content, err := Generate(u)
+	if err != nil {
+		t.Fatalf("Generate() error: %v", err)
+	}
+
+	checks := []string{
+		"After=default.target",
+		"WantedBy=default.target",
+		"ExecStart=/usr/bin/docker start myapp",
+		"ExecStop=/usr/bin/docker stop myapp",
+	}
+
+	for _, check := range checks {
+		if !strings.Contains(content, check) {
+			t.Errorf("Generate() user unit missing %q in output:\n%s", check, content)
+		}
+	}
+
+	// System unit markers must NOT appear
+	if strings.Contains(content, "WantedBy=multi-user.target") {
+		t.Error("Generate() user unit should not contain multi-user.target")
+	}
+}
+
+func TestGenerate_CustomCommand(t *testing.T) {
+	u := config.Unit{
+		Name:    "custom",
+		Runtime: "podman",
+		Command: "/usr/local/bin/mystart.sh",
+		Enabled: true,
+	}
+
+	content, err := Generate(u)
+	if err != nil {
+		t.Fatalf("Generate() error: %v", err)
+	}
+
+	if !strings.Contains(content, "ExecStart=/usr/local/bin/mystart.sh") {
+		t.Errorf("Generate() should use custom command, got:\n%s", content)
+	}
+}
+
+func TestGenerate_DockerRuntime(t *testing.T) {
+	u := config.Unit{
+		Name:    "redis",
+		Runtime: "docker",
+		Enabled: true,
+	}
+
+	content, err := Generate(u)
+	if err != nil {
+		t.Fatalf("Generate() error: %v", err)
+	}
+
+	if !strings.Contains(content, "ExecStart=/usr/bin/docker start redis") {
+		t.Errorf("Generate() wrong ExecStart for docker:\n%s", content)
+	}
+	if !strings.Contains(content, "ExecStop=/usr/bin/docker stop redis") {
+		t.Errorf("Generate() wrong ExecStop for docker:\n%s", content)
+	}
+}
+
+func TestGenerate_UnknownRuntime(t *testing.T) {
+	u := config.Unit{
+		Name:    "weird",
+		Runtime: "containerd",
+		Enabled: true,
+	}
+
+	content, err := Generate(u)
+	if err != nil {
+		t.Fatalf("Generate() should not error on unknown runtime: %v", err)
+	}
+
+	if !strings.Contains(content, "/usr/bin/containerd start weird") {
+		t.Errorf("Generate() should fall back to /usr/bin/<runtime> for unknown runtimes:\n%s", content)
+	}
+}
+
+func TestBuildExecCommands(t *testing.T) {
+	tests := []struct {
+		name      string
+		unit      config.Unit
+		wantStart string
+		wantStop  string
+	}{
+		{
+			name:      "podman",
+			unit:      config.Unit{Name: "app", Runtime: "podman"},
+			wantStart: "/usr/bin/podman start -a app",
+			wantStop:  "/usr/bin/podman stop app",
+		},
+		{
+			name:      "docker",
+			unit:      config.Unit{Name: "app", Runtime: "docker"},
+			wantStart: "/usr/bin/docker start app",
+			wantStop:  "/usr/bin/docker stop app",
+		},
+		{
+			name:      "custom command",
+			unit:      config.Unit{Name: "app", Runtime: "podman", Command: "/bin/custom"},
+			wantStart: "/bin/custom",
+			wantStop:  "",
+		},
+	}
+
+	for _, tt := range tests {
+		t.Run(tt.name, func(t *testing.T) {
+			start, stop := buildExecCommands(tt.unit)
+			if start != tt.wantStart {
+				t.Errorf("start = %q, want %q", start, tt.wantStart)
+			}
+			if stop != tt.wantStop {
+				t.Errorf("stop = %q, want %q", stop, tt.wantStop)
+			}
+		})
+	}
+}