feat: 3626 add option enable license content; disable by default (#3631)

---------
Signed-off-by: Christopher Phillips <32073428+spiffcs@users.noreply.github.com>

test/cli/license_test.go

@@ -0,0 +1,45 @@
+package cli
+
+import "testing"
+
+func Test_Licenses(t *testing.T) {
+	testImage := getFixtureImage(t, "image-unknown-licenses")
+	tests := []struct {
+		name       string
+		args       []string
+		env        map[string]string
+		assertions []traitAssertion
+	}{
+		{
+			name: "licenses default with no content",
+			args: []string{"scan", "-o", "json", testImage, "--from", "docker-archive"},
+			env:  map[string]string{"SYFT_FORMAT_PRETTY": "true"},
+			assertions: []traitAssertion{
+				assertJsonReport,
+				assertUnknownLicenseContent(false),
+				assertSuccessfulReturnCode,
+			},
+		},
+
+		{
+			name: "licenses with content",
+			args: []string{"scan", "-o", "json", testImage, "--from", "docker-archive"},
+			env:  map[string]string{"SYFT_FORMAT_PRETTY": "true", "SYFT_LICENSE_INCLUDE_UNKNOWN_LICENSE_CONTENT": "true"},
+			assertions: []traitAssertion{
+				assertJsonReport,
+				assertUnknownLicenseContent(true),
+				assertSuccessfulReturnCode,
+			},
+		},
+	}
+
+	for _, test := range tests {
+		t.Run(test.name, func(t *testing.T) {
+			cmd, stdout, stderr := runSyft(t, test.env, test.args...)
+			for _, traitFn := range test.assertions {
+				traitFn(t, stdout, stderr, cmd.ProcessState.ExitCode())
+			}
+			logOutputOnFailure(t, cmd, stdout, stderr)
+		})
+	}
+}

test/cli/test-fixtures/image-unknown-licenses/Dockerfile

@@ -0,0 +1,3 @@
+FROM alpine@sha256:c5c5fda71656f28e49ac9c5416b3643eaa6a108a8093151d6d1afc9463be8e33
+RUN rm -rf /lib/apk/db/installed
+COPY . /home/files

test/cli/trait_assertions_test.go

@@ -10,7 +10,10 @@ import (
 	"testing"
 
 	"github.com/acarl005/stripansi"
+	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
+
+	"github.com/anchore/syft/syft/format/syftjson/model"
 )
 
 type traitAssertion func(tb testing.TB, stdout, stderr string, rc int)
@@ -148,6 +151,34 @@ func assertPackageCount(length uint) traitAssertion {
 	}
 }
 
+func assertUnknownLicenseContent(required bool) traitAssertion {
+	return func(tb testing.TB, stdout, _ string, _ int) {
+		tb.Helper()
+		type NameAndLicense struct {
+			Name     string          `json:"name"`
+			Licenses []model.License `json:"Licenses"`
+		}
+		type partial struct {
+			Artifacts []NameAndLicense `json:"artifacts"`
+		}
+
+		var data partial
+		if err := json.Unmarshal([]byte(stdout), &data); err != nil {
+			tb.Errorf("expected to find a JSON report, but was unmarshalable: %+v", err)
+		}
+
+		for _, pkg := range data.Artifacts {
+			for _, lic := range pkg.Licenses {
+				if strings.Contains(lic.SPDXExpression, "UNKNOWN") && required {
+					assert.NotZero(tb, len(lic.Contents))
+				} else {
+					assert.Empty(tb, lic.Contents)
+				}
+			}
+		}
+	}
+}
+
 func assertFailingReturnCode(tb testing.TB, _, _ string, rc int) {
 	tb.Helper()
 	if rc == 0 {