add cli testing

Signed-off-by: Alex Goodman <alex.goodman@anchore.com>

test/cli/utils_test.go

@@ -0,0 +1,73 @@
+package cli
+
+import (
+	"bytes"
+	"fmt"
+	"os"
+	"os/exec"
+	"path"
+	"path/filepath"
+	"runtime"
+	"strings"
+	"testing"
+
+	"github.com/anchore/stereoscope/pkg/imagetest"
+)
+
+func getFixtureImage(t testing.TB, fixtureImageName string) string {
+	imagetest.GetFixtureImage(t, "docker-archive", fixtureImageName)
+	return imagetest.GetFixtureImageTarPath(t, fixtureImageName)
+}
+
+func runSyftCommand(t testing.TB, env map[string]string, args ...string) (*exec.Cmd, string, string) {
+	cmd := getSyftCommand(t, args...)
+	if env != nil {
+		var envList []string
+		for key, val := range env {
+			if key == "" {
+				continue
+			}
+			envList = append(envList, fmt.Sprintf("%s=%s", key, val))
+		}
+		cmd.Env = envList
+	}
+	var stdout, stderr bytes.Buffer
+	cmd.Stdout = &stdout
+	cmd.Stderr = &stderr
+
+	// ignore errors since this may be what the test expects
+	cmd.Run()
+
+	return cmd, stdout.String(), stderr.String()
+}
+
+func getSyftCommand(t testing.TB, args ...string) *exec.Cmd {
+
+	var binaryLocation string
+	if os.Getenv("SYFT_BINARY_LOCATION") != "" {
+		// SYFT_BINARY_LOCATION is relative to the repository root. (e.g., "snapshot/syft-linux_amd64/syft")
+		// This value is transformed due to the CLI tests' need for a path relative to the test directory.
+		binaryLocation = path.Join(repoRoot(t), os.Getenv("SYFT_BINARY_LOCATION"))
+	} else {
+		os := runtime.GOOS
+		if os == "darwin" {
+			os = "macos_darwin"
+		}
+
+		binaryLocation = path.Join(repoRoot(t), fmt.Sprintf("snapshot/syft-%s_%s/syft", os, runtime.GOARCH))
+	}
+	return exec.Command(binaryLocation, args...)
+}
+
+func repoRoot(t testing.TB) string {
+	t.Helper()
+	root, err := exec.Command("git", "rev-parse", "--show-toplevel").Output()
+	if err != nil {
+		t.Fatalf("unable to find repo root dir: %+v", err)
+	}
+	absRepoRoot, err := filepath.Abs(strings.TrimSpace(string(root)))
+	if err != nil {
+		t.Fatal("unable to get abs path to repo root:", err)
+	}
+	return absRepoRoot
+}