Add systemd resource budgets with TOML profiles

internal/budget/files_test.go

@@ -0,0 +1,48 @@
+package budget
+
+import (
+	"encoding/json"
+	"os"
+	"path/filepath"
+	"reflect"
+	"testing"
+)
+
+func TestWriteFiles(t *testing.T) {
+	p := homePaths(t.TempDir())
+	old := "old.scope.d/50-budget.conf"
+	put(t, filepath.Join(p.units, old), "old")
+	put(t, filepath.Join(p.units, "user.conf"), "keep")
+	put(t, filepath.Join(p.state, "files.json"), `["old.scope.d/50-budget.conf"]`)
+	files := map[string]string{"app-.scope.d/50-budget.conf": "[Scope]\nMemoryMax=8G\n", "search.slice": "[Slice]\n"}
+	if err := writeFiles(p, files); err != nil {
+		t.Fatal(err)
+	}
+	if _, err := os.Stat(filepath.Join(p.units, old)); !os.IsNotExist(err) {
+		t.Fatalf("stale owned file remains: %v", err)
+	}
+	data, err := os.ReadFile(filepath.Join(p.units, "user.conf"))
+	if err != nil || string(data) != "keep" {
+		t.Fatal("unmanaged configuration changed")
+	}
+	data, err = os.ReadFile(filepath.Join(p.state, "files.json"))
+	if err != nil {
+		t.Fatal(err)
+	}
+	var manifest []string
+	if err := json.Unmarshal(data, &manifest); err != nil {
+		t.Fatal(err)
+	}
+	if !reflect.DeepEqual(manifest, keys(files)) {
+		t.Fatal(manifest)
+	}
+	for name, want := range files {
+		data, err := os.ReadFile(filepath.Join(p.units, name))
+		if err != nil || string(data) != want {
+			t.Fatalf("%s: %q, %v", name, data, err)
+		}
+	}
+	if err := writeFiles(p, files); err != nil {
+		t.Fatal("second apply failed:", err)
+	}
+}