Add support for multiple output files in different formats (#732)

test/cli/packages_cmd_test.go

@@ -8,6 +8,7 @@ import (
 func TestPackagesCmdFlags(t *testing.T) {
 	coverageImage := "docker-archive:" + getFixtureImage(t, "image-pkg-coverage")
 	//badBinariesImage := "docker-archive:" + getFixtureImage(t, "image-bad-binaries")
+	tmp := t.TempDir() + "/"
 
 	tests := []struct {
 		name       string
@@ -32,6 +33,15 @@ func TestPackagesCmdFlags(t *testing.T) {
 				assertSuccessfulReturnCode,
 			},
 		},
+		{
+			name: "multiple-output-flags",
+			args: []string{"packages", "-o", "table", "-o", "json=" + tmp + ".tmp/multiple-output-flag-test.json", coverageImage},
+			assertions: []traitAssertion{
+				assertTableReport,
+				assertFileExists(tmp + ".tmp/multiple-output-flag-test.json"),
+				assertSuccessfulReturnCode,
+			},
+		},
 		// I haven't been able to reproduce locally yet, but in CI this has proven to be unstable:
 		// For the same commit:
 		//   pass: https://github.com/anchore/syft/runs/4611344142?check_suite_focus=true

test/cli/trait_assertions_test.go

@@ -2,6 +2,7 @@ package cli
 
 import (
 	"encoding/json"
+	"os"
 	"regexp"
 	"strings"
 	"testing"
@@ -114,3 +115,12 @@ func assertSuccessfulReturnCode(tb testing.TB, _, _ string, rc int) {
 		tb.Errorf("expected no failure but got rc=%d", rc)
 	}
 }
+
+func assertFileExists(file string) traitAssertion {
+	return func(tb testing.TB, _, _ string, _ int) {
+		tb.Helper()
+		if _, err := os.Stat(file); err != nil {
+			tb.Errorf("expected file to exist %s", file)
+		}
+	}
+}