Give each failure one error value (closes #113)

internal/cli drops its copies of vault.ErrSecretNotFound, ErrVaultNotFound,
ErrVersionNotFound and ErrSecretExists and of the secret package's keychain
and Secure Enclave errors, and its second error for an unknown unlocker
type, an invalid mnemonic, a length below 1, an unsupported secret type and
an oversized secret. vault.ErrNilValueBuffer becomes
secret.ErrNilValueBuffer. Every error of secret.ReadPassphrase wraps
ErrPassphraseNotRead. ResolveGPGKeyFingerprint returns ErrGPGKeyNotFound for
a key the keyring lacks. storeInKeychain returns errNilDataBuffer. bip85's
ErrPasswordTooShort and ErrEncodedTooShort go with their unreachable checks,
as does the macOS check in macOS-only code. Tests that matched these
errors' text use errors.Is.

Model: opus-5-5

internal/cli/move_test.go

@@ -45,15 +45,6 @@ func TestRejectedMoveWithinVaultLeavesStateUnchanged(t *testing.T) {
 		{`mv --force work:x ""`, workX, "", true, ontoItself},
 		// "work" is a vault name, so the destination is work:x.
 		{"mv --force work:x work", workX, "work", true, ontoItself},
-		{
-			"mv work:nosuch work:y", "work:nosuch", "work:y", false,
-			"secret 'nosuch' not found",
-		},
-		// Only an existing vault is used.
-		{
-			"mv --force nosuch:x nosuch:y", "nosuch:x", "nosuch:y", true,
-			"vault 'nosuch' does not exist",
-		},
 	}
 
 	for _, tt := range tests {
@@ -70,6 +61,33 @@ func TestRejectedMoveWithinVaultLeavesStateUnchanged(t *testing.T) {
 		})
 	}
 
+	missing := []struct {
+		command      string
+		source, dest string
+		force        bool
+		want         error
+	}{
+		{
+			"mv work:nosuch work:y", "work:nosuch", "work:y", false,
+			vault.ErrSecretNotFound,
+		},
+		// Only an existing vault is used.
+		{
+			"mv --force nosuch:x nosuch:y", "nosuch:x", "nosuch:y", true,
+			vault.ErrVaultNotFound,
+		},
+	}
+
+	for _, tt := range missing {
+		t.Run(tt.command, func(t *testing.T) {
+			t.Parallel()
+
+			requireRejectedAndUnchanged(t, before, tt.want, func(c *cli.Instance) error {
+				return c.MoveSecret(&cobra.Command{}, tt.source, tt.dest, tt.force)
+			})
+		})
+	}
+
 	// Each of these spells "work" a second way. The spelling is not a valid
 	// vault name, so the move is not taken for a move between two vaults,
 	// which would delete the destination, here the source.