feat: Add support for per-project sandbox overlays (#294)

* feat: Add support for per-project sandbox overlays

* chore: Maintain consistency with TUI experience

* fix: Code review fixes

cmd/sandbox/project_list_test.go

@@ -0,0 +1,83 @@
+package sandbox
+
+import (
+	"bytes"
+	"encoding/json"
+	"testing"
+
+	"github.com/safedep/pmg/config"
+	pmgsandbox "github.com/safedep/pmg/sandbox"
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func execProjectList(t *testing.T, overlayDir string, args ...string) (string, string, error) {
+	t.Helper()
+	cmd := newProjectListCommand(projectDeps{
+		overlayDir: func() string { return overlayDir },
+	})
+	var stdout, stderr bytes.Buffer
+	cmd.SetOut(&stdout)
+	cmd.SetErr(&stderr)
+	cmd.SetArgs(args)
+	err := cmd.Execute()
+	return stdout.String(), stderr.String(), err
+}
+
+func TestProjectList_Empty(t *testing.T) {
+	dir := t.TempDir()
+	stdout, _, err := execProjectList(t, dir)
+	require.NoError(t, err)
+	assert.Contains(t, stdout, "No project overlays")
+}
+
+func TestProjectList_Human(t *testing.T) {
+	dir := t.TempDir()
+	for _, repo := range []string{"/repo/a", "/repo/b"} {
+		_, err := pmgsandbox.SaveOverlay(dir, repo, &pmgsandbox.Overlay{
+			Allow: []pmgsandbox.OverlayAllow{{Type: config.SandboxAllowExec, Value: "/bin/x"}},
+		})
+		require.NoError(t, err)
+	}
+
+	stdout, _, err := execProjectList(t, dir)
+	require.NoError(t, err)
+	assert.Contains(t, stdout, "/repo/a")
+	assert.Contains(t, stdout, "/repo/b")
+}
+
+func TestProjectList_JSON(t *testing.T) {
+	dir := t.TempDir()
+	for _, repo := range []string{"/repo/a", "/repo/b"} {
+		_, err := pmgsandbox.SaveOverlay(dir, repo, &pmgsandbox.Overlay{
+			Allow: []pmgsandbox.OverlayAllow{{Type: config.SandboxAllowExec, Value: "/bin/x"}},
+		})
+		require.NoError(t, err)
+	}
+
+	stdout, _, err := execProjectList(t, dir, "--json")
+	require.NoError(t, err)
+	var payload struct {
+		Entries []struct {
+			RepoRoot string `json:"repo_root"`
+			Entries  int    `json:"entries"`
+			Path     string `json:"path"`
+		} `json:"entries"`
+	}
+	require.NoError(t, json.Unmarshal([]byte(stdout), &payload))
+	require.Len(t, payload.Entries, 2)
+	assert.Equal(t, "/repo/a", payload.Entries[0].RepoRoot)
+	assert.Equal(t, 1, payload.Entries[0].Entries)
+}
+
+func TestProjectList_JSONEmpty(t *testing.T) {
+	dir := t.TempDir()
+	stdout, _, err := execProjectList(t, dir, "--json")
+	require.NoError(t, err)
+	var payload struct {
+		Entries []any `json:"entries"`
+	}
+	require.NoError(t, json.Unmarshal([]byte(stdout), &payload))
+	assert.NotNil(t, payload.Entries)
+	assert.Empty(t, payload.Entries)
+}