use format flag to handle json output in verify cmd

Signed-off-by: Meredith Lancaster <malancas@github.com>

pkg/cmd/attestation/verify/options.go

@@ -8,6 +8,7 @@ import (
 	"github.com/cli/cli/v2/pkg/cmd/attestation/api"
 	"github.com/cli/cli/v2/pkg/cmd/attestation/artifact/oci"
 	"github.com/cli/cli/v2/pkg/cmd/attestation/io"
+	"github.com/cli/cli/v2/pkg/cmdutil"
 )
 
 // Options captures the options for the verify command
@@ -17,7 +18,6 @@ type Options struct {
 	CustomTrustedRoot    string
 	DenySelfHostedRunner bool
 	DigestAlgorithm      string
-	JsonResult           bool
 	NoPublicGood         bool
 	OIDCIssuer           string
 	Owner                string
@@ -28,6 +28,7 @@ type Options struct {
 	Logger               *io.Handler
 	Limit                int
 	OCIClient            oci.Client
+	exporter             cmdutil.Exporter
 }
 
 // Clean cleans the file path option values

pkg/cmd/attestation/verify/verify.go

@@ -120,9 +120,9 @@ func NewVerifyCmd(f *cmdutil.Factory, runF func(*Options) error) *cobra.Command
 	verifyCmd.MarkFlagsMutuallyExclusive("owner", "repo")
 	verifyCmd.MarkFlagsOneRequired("owner", "repo")
 	verifyCmd.Flags().BoolVarP(&opts.NoPublicGood, "no-public-good", "", false, "Only verify attestations signed with GitHub's Sigstore instance")
-	verifyCmd.Flags().BoolVarP(&opts.JsonResult, "json-result", "j", false, "Output verification result as JSON lines")
 	verifyCmd.Flags().StringVarP(&opts.CustomTrustedRoot, "custom-trusted-root", "", "", "Path to a custom trustedroot.json file to use for verification")
 	verifyCmd.Flags().IntVarP(&opts.Limit, "limit", "L", api.DefaultLimit, "Maximum number of attestations to fetch")
+	cmdutil.AddFormatFlags(verifyCmd, &opts.exporter)
 	// policy enforcement flags
 	verifyCmd.Flags().BoolVarP(&opts.DenySelfHostedRunner, "deny-self-hosted-runners", "", false, "Fail verification for attestations generated on self-hosted runners.")
 	verifyCmd.Flags().StringVarP(&opts.SAN, "cert-identity", "", "", "Enforce that the certificate's subject alternative name matches the provided value exactly")
@@ -191,7 +191,7 @@ func runVerify(opts *Options) error {
 
 	opts.Logger.Println(opts.Logger.ColorScheme.Green("All attestations have been successfully verified!"))
 
-	if opts.JsonResult {
+	if opts.exporter != nil {
 		verificationResults := sigstoreRes.VerifyResults
 		// print each result as JSON line
 
@@ -204,8 +204,9 @@ func runVerify(opts *Options) error {
 
 			jsonResults[i] = string(jsonBytes)
 		}
-
-		fmt.Fprintf(opts.Logger.IO.Out, "%v", jsonResults)
+		if err = opts.exporter.Write(opts.Logger.IO, jsonResults); err != nil {
+			return fmt.Errorf("failed to write JSON output")
+		}
 	}
 
 	// All attestations passed verification and policy evaluation

pkg/cmd/attestation/verify/verify_test.go

@@ -194,7 +194,6 @@ func TestNewVerifyCmd(t *testing.T) {
 			assert.Equal(t, tc.wants.CustomTrustedRoot, opts.CustomTrustedRoot)
 			assert.Equal(t, tc.wants.DenySelfHostedRunner, opts.DenySelfHostedRunner)
 			assert.Equal(t, tc.wants.DigestAlgorithm, opts.DigestAlgorithm)
-			assert.Equal(t, tc.wants.JsonResult, opts.JsonResult)
 			assert.Equal(t, tc.wants.Limit, opts.Limit)
 			assert.Equal(t, tc.wants.NoPublicGood, opts.NoPublicGood)
 			assert.Equal(t, tc.wants.OIDCIssuer, opts.OIDCIssuer)