Make -v count once and accept -vv for debug output (closes #125)

urfave/cli before v2.25.5 counted a flag given by its alias twice, so
one -v or --verbose already gave debug output. Bump it to v2.27.7, the
latest v2 release, which counts it once: one -v gives verbose output,
two give debug.

Turn on urfave/cli's UseShortOptionHandling so single-letter flags
combine at the root and in every subcommand; -vv now works as the -v
help text says.

-v and --verbose together stay refused: urfave/cli v2 refuses any flag
given under two of its names.

The bump drops "[arguments...]" from usage lines, so generate and fetch
now name their arguments. Test runs now start at the default log level.

Model: opus-5-5

internal/cli/entry_test.go

@@ -8,6 +8,8 @@ import (
 	"io"
 	"math/rand"
 	"os"
+	"slices"
+	"strings"
 	"sync"
 	"testing"
 
@@ -30,6 +32,7 @@ const (
 	testFlagBase    = "--base"
 	testFlagNoExtra = "--no-extra-files"
 	testFlagVersion = "--version"
+	testFlagVerbose = "--verbose"
 )
 
 var errSimulatedWrite = errors.New("simulated write failure")
@@ -42,20 +45,32 @@ var errSimulatedWrite = errors.New("simulated write failure")
 var runMu sync.Mutex
 
 // runCLI invokes RunWithOptions while holding runMu so parallel tests
-// capture their own output. Before releasing the lock it points the
-// process-global logger at io.Discard: other tests log outside the lock
-// (manifest loads, scans), and those lines must not land in this run's
-// buffers once it has returned and its test is reading them.
+// capture their own output, and returns its exit code.
 func runCLI(opts *RunOptions) int {
+	exitCode, _ := runCLIWithLevel(opts)
+
+	return exitCode
+}
+
+// runCLIWithLevel is runCLI that also returns the log level the run left
+// set, read while runMu still keeps other runs from changing it. Each run
+// starts at the default level, as a new process does. Before releasing the
+// lock it points the process-global logger at io.Discard: other tests log
+// outside the lock (manifest loads, scans), and those lines must not land in
+// this run's buffers once it has returned and its test is reading them.
+func runCLIWithLevel(opts *RunOptions) (int, log.Level) {
 	runMu.Lock()
 	defer runMu.Unlock()
 
+	log.SetLevel(log.InfoLevel)
+
 	exitCode := RunWithOptions(opts)
+	level := log.GetLevel()
 
 	log.SetOutput(io.Discard, io.Discard)
 	log.Init()
 
-	return exitCode
+	return exitCode, level
 }
 
 func TestMain(m *testing.M) {
@@ -235,6 +250,87 @@ func TestRootVerbosityFlags(t *testing.T) {
 	})
 }
 
+// commandsTakingVerbose returns the command lines -v can follow: the root and
+// the generate, check, freshen and fetch subcommands.
+func commandsTakingVerbose() [][]string {
+	return [][]string{
+		{testApp},
+		{testApp, cmdGenerate},
+		{testApp, cmdCheck},
+		{testApp, cmdFreshen},
+		{testApp, cmdFetch},
+	}
+}
+
+// TestVerboseCount asserts that one -v or --verbose gives verbose output and
+// two -v give debug output (issue #125). urfave/cli before v2.25.5 counted a
+// flag given by its alias twice, so one -v gave debug output.
+func TestVerboseCount(t *testing.T) {
+	t.Parallel()
+
+	cases := []struct {
+		flags []string
+		want  log.Level
+	}{
+		{[]string{"-v"}, log.VerboseLevel},
+		{[]string{testFlagVerbose}, log.VerboseLevel},
+		{[]string{"-v", "-v"}, log.DebugLevel},
+	}
+
+	for _, command := range commandsTakingVerbose() {
+		for _, tc := range cases {
+			args := slices.Concat(command, tc.flags)
+
+			t.Run(strings.Join(args, " "), func(t *testing.T) {
+				t.Parallel()
+
+				_, level := runCLIWithLevel(testOpts(args, afero.NewMemMapFs()))
+				assert.Equal(t, tc.want, level)
+			})
+		}
+	}
+}
+
+// TestCombinedShortVerbose asserts that -vv gives debug output wherever -v
+// is taken, as the -v help text says (issue #125).
+func TestCombinedShortVerbose(t *testing.T) {
+	t.Parallel()
+
+	for _, command := range commandsTakingVerbose() {
+		args := slices.Concat(command, []string{"-vv"})
+
+		t.Run(strings.Join(args, " "), func(t *testing.T) {
+			t.Parallel()
+
+			opts := testOpts(args, afero.NewMemMapFs())
+			_, level := runCLIWithLevel(opts)
+			assert.Equal(t, log.DebugLevel, level, "stderr: %s", testStderr(t, opts))
+		})
+	}
+}
+
+// TestShortAndLongVerboseRefused asserts that -v and --verbose given together
+// are refused (issue #125): urfave/cli v2 refuses any flag given under two of
+// its names, and accepting it would take parsing the arguments by hand.
+func TestShortAndLongVerboseRefused(t *testing.T) {
+	t.Parallel()
+
+	for _, command := range commandsTakingVerbose() {
+		args := slices.Concat(command, []string{"-v", testFlagVerbose})
+
+		t.Run(strings.Join(args, " "), func(t *testing.T) {
+			t.Parallel()
+
+			opts := testOpts(args, afero.NewMemMapFs())
+			exitCode, level := runCLIWithLevel(opts)
+
+			assert.Equal(t, 1, exitCode)
+			assert.Contains(t, testStderr(t, opts), "Cannot use two forms of the same flag")
+			assert.Equal(t, log.InfoLevel, level)
+		})
+	}
+}
+
 func TestHelpCommand(t *testing.T) {
 	t.Parallel()