Document that --json skips the confirmation prompt (closes #268)

snapshot remove and prune delete without asking under --json, because a
prompt on stdout would break the JSON document. Their --json help and
README entries named only --force as skipping the prompt. Both now say
--json skips it too. One test checks the --json help of both commands;
another runs prune with --json, no --force and empty stdin, and checks
that the unreferenced blob is deleted and stdout holds only the JSON
document.

Model: opus-5-5

README.md

@@ -359,7 +359,8 @@ on the destination in one go, use `vaultik remote nuke --force`.
 * `--local-only`: Skip remote cleanup; only touch the local index
 * `--dry-run`: Show what would be deleted without deleting
 * `--force`: Skip confirmation prompt
-* `--json`: Output result as JSON
+* `--json`: Output result as JSON. Also skips the confirmation prompt, as
+  `--force` does.
 
 **`snapshot restore`**: Restore files from a backup snapshot.
 * Requires `VAULTIK_AGE_SECRET_KEY` environment variable
@@ -383,7 +384,8 @@ manifests — network cost scales with the number of snapshots. `snapshot
 create --prune` runs the same cleanup automatically; this is the
 manual entry point for the same work.
 * `--force`: Skip confirmation prompt
-* `--json`: Output stats as JSON
+* `--json`: Output stats as JSON. Also skips the confirmation prompt, as
+  `--force` does.
 
 **`info`**: Display system configuration, storage settings, encryption
 recipients, and local database statistics.

TODO.md

@@ -30,6 +30,14 @@ the tag exists and is exercised; what is left is merging `next` to
   snapshots.id`. When the local index already has a snapshot with the
   ID, the create now waits a second and takes a new timestamp.
 
+- 2026-10-07: Documented that `--json` skips the confirmation prompt of
+  `snapshot remove` and `prune`
+  ([issue #268](https://git.eeqj.de/sneak/vaultik/issues/268)). Both
+  commands delete without asking under `--json`, since a prompt on stdout
+  would break the JSON document, but the help and the README described
+  only `--force` as skipping it. The `--json` help of both commands and
+  their README entries now say so.
+
 - 2026-10-07: Made a symlink whose target cannot be read stop the backup
   ([issue #269](https://git.eeqj.de/sneak/vaultik/issues/269)). It was
   left out of the snapshot with only a debug log line, even without

internal/cli/json_help_test.go

@@ -0,0 +1,24 @@
+package cli //nolint:testpackage // exercises the unexported command constructor
+
+import (
+	"testing"
+
+	"github.com/spf13/cobra"
+	"github.com/stretchr/testify/assert"
+)
+
+// TestJSONHelpSaysConfirmationPromptIsSkipped checks that the --json help
+// of `snapshot remove` and `prune` says the flag skips the confirmation
+// prompt. Both delete without asking under --json, since a prompt on
+// stdout would break the JSON document.
+func TestJSONHelpSaysConfirmationPromptIsSkipped(t *testing.T) {
+	t.Parallel()
+
+	for _, cmd := range []*cobra.Command{
+		newSnapshotRemoveCommand(),
+		NewPruneCommand(),
+	} {
+		assert.Contains(t, cmd.Flags().Lookup("json").Usage,
+			"skips the confirmation prompt", cmd.Name())
+	}
+}

internal/cli/prune.go

@@ -57,7 +57,8 @@ referenced.`,
 	}
 
 	cmd.Flags().BoolVar(&opts.Force, "force", false, "Skip confirmation prompt")
-	cmd.Flags().BoolVar(&opts.JSON, "json", false, "Output pruning stats as JSON")
+	cmd.Flags().BoolVar(&opts.JSON, "json", false,
+		"Output pruning stats as JSON; skips the confirmation prompt, as --force does")
 
 	return cmd
 }

internal/cli/snapshot.go

@@ -280,7 +280,8 @@ nuke --force' — it is the single supported entry point for that.`,
 	cmd.Flags().BoolVarP(&opts.Force, "force", "f", false, "Skip confirmation prompt")
 	cmd.Flags().BoolVar(&opts.DryRun, "dry-run", false,
 		"Show what would be removed without removing")
-	cmd.Flags().BoolVar(&opts.JSON, "json", false, "Output result as JSON")
+	cmd.Flags().BoolVar(&opts.JSON, "json", false,
+		"Output result as JSON; skips the confirmation prompt, as --force does")
 	cmd.Flags().BoolVar(&opts.LocalOnly, "local-only", false,
 		"Skip remote cleanup; only touch the local index")
 

internal/vaultik/prune_json_test.go

@@ -0,0 +1,40 @@
+package vaultik_test
+
+import (
+	"encoding/json"
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+	"sneak.berlin/go/vaultik/internal/log"
+	"sneak.berlin/go/vaultik/internal/vaultik"
+)
+
+// TestPruneBlobs_JSONDeletesWithoutAsking checks that prune with --json
+// and without --force deletes an unreferenced blob without the
+// confirmation prompt. Stdin is empty, so a prompt would read no answer
+// and cancel, and its text would come before the JSON document.
+func TestPruneBlobs_JSONDeletesWithoutAsking(t *testing.T) {
+	log.Initialize(log.Config{})
+	t.Parallel()
+
+	env := newListEnv(t)
+
+	// The store holds no manifest, so nothing references this blob.
+	addBlob(t, env.store.testStorer, testBlobHashA)
+
+	err := env.v.PruneBlobs(&vaultik.PruneOptions{JSON: true})
+	require.NoError(t, err)
+
+	blobKey := "blobs/" + testBlobHashA[:2] + "/" + testBlobHashA[2:4] +
+		"/" + testBlobHashA
+	assert.False(t, env.store.hasKey(blobKey),
+		"the unreferenced blob must be deleted")
+
+	var result vaultik.PruneBlobsResult
+
+	require.NoError(t, json.Unmarshal(env.stdout.Bytes(), &result),
+		"stdout must hold only the JSON document, got:\n%s",
+		env.stdout.String())
+	assert.Equal(t, 1, result.BlobsDeleted)
+}