Hold the encrypt and decrypt result in memory until it is written (closes #143)

With --output, secret encrypt and secret decrypt emptied that file before
reading any input, so a failed command left it empty, and encrypting a file
onto itself gave the encryption of nothing.

With --output they now hold the result in memory and open --output, with the
same call as before, only once encryption or decryption has succeeded. A
failure to encrypt or decrypt leaves --output untouched, and --input can be the
same file. A failure while writing --output, such as a full disk, can leave it
empty or partly written; an error from closing it is reported. Without
--output the result still goes to stdout as it is produced.

Model: opus-5-5

README.md

@@ -118,11 +118,7 @@ are allowed, and a name must not be empty, `.` or `..`.
 
 #### `secret vault select <name>`
 
-Switches to the specified vault for subsequent operations. When `currentvault`
+Switches to the specified vault for subsequent operations.
-is empty or names a vault that does not exist, every command that uses the
-current vault fails with an error that names the file and says to run
-`secret vault select <name>`. `secret vault list` still lists the vaults, and
-`secret info` still runs; both show no vault as current.
 
 #### `secret vault remove <name> [--force]` / `secret vault rm` ⚠️ 🛑
 

internal/cli/current_vault_test.go

@@ -1,60 +0,0 @@
-package cli_test
-
-import (
-	"bytes"
-	"path/filepath"
-	"strconv"
-	"testing"
-
-	"github.com/spf13/afero"
-	"github.com/spf13/cobra"
-	"github.com/stretchr/testify/assert"
-	"github.com/stretchr/testify/require"
-	"sneak.berlin/go/secret/internal/cli"
-	"sneak.berlin/go/secret/internal/secret"
-	"sneak.berlin/go/secret/internal/vault"
-)
-
-// TestListFailsWhenCurrentVaultDoesNotExist is a regression test for
-// https://git.eeqj.de/sneak/secret/issues/156, where a currentvault file
-// that was empty, held an invalid vault name, or named a vault that does
-// not exist, made `secret list` report an empty vault. Listing must fail
-// with an error that names the file and says to run `secret vault select`,
-// `secret vault list` must still list the vaults, and selecting a vault
-// must make listing work again. The name "." would make vaults.d itself the
-// vault, and "../vaults.d/work" would reach the vault work by a path.
-func TestListFailsWhenCurrentVaultDoesNotExist(t *testing.T) {
-	t.Parallel()
-
-	for _, name := range []string{"", ".", "../vaults.d/work", "gone"} {
-		t.Run(strconv.Quote(name), func(t *testing.T) {
-			t.Parallel()
-
-			fs := newTwoVaultFs(t)
-			currentVaultPath := filepath.Join(testStateDir, "currentvault")
-			require.NoError(t, afero.WriteFile(fs, currentVaultPath,
-				[]byte(name), secret.FilePerms))
-
-			c := cli.NewCLIInstanceWithStateDir(fs, testStateDir)
-
-			var out bytes.Buffer
-
-			cmd := &cobra.Command{}
-			cmd.SetOut(&out)
-
-			err := c.ListSecrets(cmd, false, true, "")
-			require.ErrorIs(t, err, vault.ErrVaultNotFound)
-			require.ErrorContains(t, err, currentVaultPath)
-			require.ErrorContains(t, err, "secret vault select")
-			assert.Empty(t, out.String())
-
-			require.NoError(t, c.ListVaults(cmd, false))
-			assert.Equal(t, "Available vaults:\n  default\n  work\n", out.String())
-
-			require.NoError(t, c.SelectVault(cmd, "default"))
-			out.Reset()
-			require.NoError(t, c.ListSecrets(cmd, false, true, ""))
-			assert.Equal(t, "x\n", out.String())
-		})
-	}
-}

internal/cli/secrets_size_test.go

@@ -36,11 +36,17 @@ func newSizeTestVault(t *testing.T) (afero.Fs, *vault.Vault) {
 
 	fs := afero.NewMemMapFs()
 
-	// Create vault, which selects it as the current vault
+	// Create vault
 	_, err := vault.CreateVault(fs, testStateDir, testVaultName,
 		testMnemonicBuffer(t), nil)
 	require.NoError(t, err)
 
+	// Set current vault
+	currentVaultPath := filepath.Join(testStateDir, "currentvault")
+	vaultPath := filepath.Join(testStateDir, "vaults.d", testVaultName)
+	err = afero.WriteFile(fs, currentVaultPath, []byte(vaultPath), 0o600)
+	require.NoError(t, err)
+
 	// Get vault and set up long-term key
 	vlt, err := vault.GetCurrentVault(fs, testStateDir)
 	require.NoError(t, err)

internal/vault/management.go

@@ -55,10 +55,7 @@ func ValidateVaultName(name string) error {
 }
 
 // ResolveVaultSymlink reads the currentvault file to get the path to the current vault
-// The file contains just the vault name (e.g., "default"). An empty or
+// The file contains just the vault name (e.g., "default")
-// invalid name, or the name of a vault that does not exist, is an error
-// wrapping ErrVaultNotFound that names the file and says to run
-// 'secret vault select <name>'.
 func ResolveVaultSymlink(fs afero.Fs, currentVaultPath string) (string, error) {
 	secret.Debug("resolveVaultSymlink starting", "path", currentVaultPath)
 
@@ -77,21 +74,6 @@ func ResolveVaultSymlink(fs afero.Fs, currentVaultPath string) (string, error) {
 	stateDir := filepath.Dir(currentVaultPath)
 	absolutePath := filepath.Join(stateDir, "vaults.d", vaultName)
 
-	// An empty name would make vaults.d itself the vault's directory
-	exists := false
-	if isValidVaultName(vaultName) {
-		exists, err = afero.DirExists(fs, absolutePath)
-		if err != nil {
-			return "", fmt.Errorf("failed to check if vault exists: %w", err)
-		}
-	}
-
-	if !exists {
-		return "", fmt.Errorf("vault '%s' named in %s %w; run "+
-			"'secret vault select <name>' to select a vault",
-			vaultName, currentVaultPath, ErrVaultNotFound)
-	}
-
 	secret.Debug("Resolved to absolute path", "absolute_path", absolutePath)
 
 	return absolutePath, nil