Move the CLI to urfave/cli v3 (closes #110)

Ported per the library's v2-to-v3 migration guide: the app is a root
cli.Command, actions take a context and the command, and flag
environment variables become value sources. -v, -q and the version flag
are local so, as before, only the commands defining them accept them.
Every command stops reading flags at its first argument, as v2 did.
ErrWriter is stdout so usage errors print with their help. The action's
context reaches the manifest download in check, export and list.
testify rises to v1.12.1, which v3 requires; the urfave_cli_no_docs
build tag, which v3 lacks, is dropped. v3 accepts a flag given under two
names, so -v --verbose gives debug output, and the test pinning the
refusal becomes a TestVerboseCount case.

Model: opus-5-5

internal/cli/check.go

@@ -16,7 +16,7 @@ import (
 
 	"github.com/dustin/go-humanize"
 	"github.com/spf13/afero"
-	"github.com/urfave/cli/v2"
+	"github.com/urfave/cli/v3"
 	"sneak.berlin/go/mfer/internal/log"
 	"sneak.berlin/go/mfer/mfer"
 )
@@ -96,8 +96,10 @@ func findManifest(fs afero.Fs, dir string) (string, error) {
 
 // fetchManifestToTemp downloads a manifest URL to a temporary file and
 // returns the temp file path. The caller is responsible for removing it.
-func (mfa *CLIApp) fetchManifestToTemp(url string) (string, error) {
-	rc, fetchErr := mfa.openManifestReader(url)
+func (mfa *CLIApp) fetchManifestToTemp(
+	ctx context.Context, url string,
+) (string, error) {
+	rc, fetchErr := mfa.openManifestReader(ctx, url)
 	if fetchErr != nil {
 		return "", fetchErr
 	}
@@ -208,13 +210,15 @@ func countCheckFailures(
 // findExtraFiles reports files present on disk but absent from the
 // manifest, and anything the search cannot read: each is a failure under
 // --no-extra-files, otherwise a warning.
-func findExtraFiles(ctx *cli.Context, chk *mfer.Checker, failures *int64) error {
+func findExtraFiles(
+	ctx context.Context, cmd *cli.Command, chk *mfer.Checker, failures *int64,
+) error {
 	extraResults := make(chan mfer.Result, 1)
 	extraDone := make(chan struct{})
 
 	go func() {
 		for result := range extraResults {
-			if ctx.Bool("no-extra-files") {
+			if cmd.Bool("no-extra-files") {
 				*failures++
 
 				log.Infof("%s: %s (%s)", result.Status, result.Path, result.Message)
@@ -226,7 +230,7 @@ func findExtraFiles(ctx *cli.Context, chk *mfer.Checker, failures *int64) error
 		close(extraDone)
 	}()
 
-	err := chk.FindExtraFiles(ctx.Context, extraResults)
+	err := chk.FindExtraFiles(ctx, extraResults)
 	if err != nil {
 		return fmt.Errorf("failed to check for extra files: %w", err)
 	}
@@ -238,7 +242,9 @@ func findExtraFiles(ctx *cli.Context, chk *mfer.Checker, failures *int64) error
 
 // runCheck runs the manifest check with progress and result reporting
 // and returns the number of failures.
-func runCheck(ctx *cli.Context, chk *mfer.Checker, showProgress bool) (int64, error) {
+func runCheck(
+	ctx context.Context, cmd *cli.Command, chk *mfer.Checker, showProgress bool,
+) (int64, error) {
 	// Set up results channel
 	results := make(chan mfer.Result, 1)
 
@@ -264,7 +270,7 @@ func runCheck(ctx *cli.Context, chk *mfer.Checker, showProgress bool) (int64, er
 	go countCheckFailures(results, &failures, done)
 
 	// Run check
-	err := chk.Check(ctx.Context, results, progress)
+	err := chk.Check(ctx, results, progress)
 
 	progressWg.Wait()
 
@@ -275,7 +281,7 @@ func runCheck(ctx *cli.Context, chk *mfer.Checker, showProgress bool) (int64, er
 	// Wait for results processing to complete
 	<-done
 
-	err = findExtraFiles(ctx, chk, &failures)
+	err = findExtraFiles(ctx, cmd, chk, &failures)
 	if err != nil {
 		return 0, err
 	}
@@ -283,17 +289,19 @@ func runCheck(ctx *cli.Context, chk *mfer.Checker, showProgress bool) (int64, er
 	return failures, nil
 }
 
-func (mfa *CLIApp) checkManifestOperation(ctx *cli.Context) error {
+func (mfa *CLIApp) checkManifestOperation(
+	ctx context.Context, cmd *cli.Command,
+) error {
 	log.Debug("checkManifestOperation()")
 
-	manifestPath, err := mfa.resolveManifestArg(ctx)
+	manifestPath, err := mfa.resolveManifestArg(cmd)
 	if err != nil {
 		return fmt.Errorf("check: %w", err)
 	}
 
 	// URL manifests need to be downloaded to a temp file for the checker
 	if isHTTPURL(manifestPath) {
-		tmpPath, tmpErr := mfa.fetchManifestToTemp(manifestPath)
+		tmpPath, tmpErr := mfa.fetchManifestToTemp(ctx, manifestPath)
 		if tmpErr != nil {
 			return fmt.Errorf("check: %w", tmpErr)
 		}
@@ -303,12 +311,13 @@ func (mfa *CLIApp) checkManifestOperation(ctx *cli.Context) error {
 		manifestPath = tmpPath
 	}
 
-	basePath := ctx.String("base")
-	showProgress := ctx.Bool("progress")
+	basePath := cmd.String("base")
+	showProgress := cmd.Bool("progress")
 
 	log.Infof("checking manifest %s with base %s", manifestPath, basePath)
 
 	// Create checker
+	//nolint:contextcheck // mfer loads a manifest without a context
 	chk, err := mfer.NewChecker(&mfer.CheckerOptions{
 		ManifestPath: manifestPath,
 		BasePath:     basePath,
@@ -319,9 +328,9 @@ func (mfa *CLIApp) checkManifestOperation(ctx *cli.Context) error {
 	}
 
 	// Check signature requirement
-	requiredSigner := ctx.String(flagRequireSignature)
+	requiredSigner := cmd.String(flagRequireSignature)
 	if requiredSigner != "" {
-		err = verifyRequiredSigner(ctx.Context, chk, requiredSigner)
+		err = verifyRequiredSigner(ctx, chk, requiredSigner)
 		if err != nil {
 			return err
 		}
@@ -330,7 +339,7 @@ func (mfa *CLIApp) checkManifestOperation(ctx *cli.Context) error {
 	log.Infof("manifest contains %d files, %s", chk.FileCount(),
 		humanize.IBytes(safeUint64(int64(chk.TotalBytes()))))
 
-	failures, err := runCheck(ctx, chk, showProgress)
+	failures, err := runCheck(ctx, cmd, chk, showProgress)
 	if err != nil {
 		return err
 	}