Only burn one sat (ordinals#4063)

src/subcommand/wallet/burn.rs

@@ -28,12 +28,6 @@ pub struct Burn {
     you understand the implications."
   )]
   no_limit: bool,
-  #[arg(
-    long,
-    help = "Target <AMOUNT> postage with sent inscriptions. [default: 10000 sat]",
-    value_name = "AMOUNT"
-  )]
-  postage: Option<Amount>,
   inscription: InscriptionId,
 }
 
@@ -47,21 +41,10 @@ impl Burn {
 
     let metadata = WalletCommand::parse_metadata(self.cbor_metadata, self.json_metadata)?;
 
-    let Some(value) = inscription_info.value else {
-      bail!("Cannot burn unbound inscription");
-    };
-
-    let value = Amount::from_sat(value);
-
-    ensure! {
-      value <= TARGET_POSTAGE,
-      "Cannot burn inscription contained in UTXO exceeding {TARGET_POSTAGE}",
-    }
-
-    ensure! {
-      self.postage.unwrap_or_default() <= TARGET_POSTAGE,
-      "Postage may not exceed {TARGET_POSTAGE}",
-    }
+    ensure!(
+      inscription_info.value.is_some(),
+      "Cannot burn unbound inscription"
+    );
 
     let mut builder = script::Builder::new().push_opcode(opcodes::all::OP_RETURN);
 
@@ -96,12 +79,14 @@ impl Burn {
       MAX_STANDARD_OP_RETURN_SIZE,
     );
 
+    let burn_amount = Amount::from_sat(1);
+
     let unsigned_transaction = Self::create_unsigned_burn_transaction(
       &wallet,
       inscription_info.satpoint,
-      self.postage,
       self.fee_rate,
       script_pubkey,
+      burn_amount,
     )?;
 
     let base_size = unsigned_transaction.base_size();
@@ -110,8 +95,11 @@ impl Burn {
       "transaction base size less than minimum standard tx nonwitness size: {base_size} < 65",
     );
 
-    let (txid, psbt, fee) =
-      wallet.sign_and_broadcast_transaction(unsigned_transaction, self.dry_run, Some(value))?;
+    let (txid, psbt, fee) = wallet.sign_and_broadcast_transaction(
+      unsigned_transaction,
+      self.dry_run,
+      Some(burn_amount),
+    )?;
 
     Ok(Some(Box::new(send::Output {
       txid,
@@ -124,9 +112,9 @@ impl Burn {
   fn create_unsigned_burn_transaction(
     wallet: &Wallet,
     satpoint: SatPoint,
-    postage: Option<Amount>,
     fee_rate: FeeRate,
     script_pubkey: ScriptBuf,
+    burn_amount: Amount,
   ) -> Result<Transaction> {
     let runic_outputs = wallet.get_runic_outputs()?;
 
@@ -137,8 +125,6 @@ impl Burn {
 
     let change = [wallet.get_change_address()?, wallet.get_change_address()?];
 
-    let postage = postage.map(Target::ExactPostage).unwrap_or(Target::Postage);
-
     Ok(
       TransactionBuilder::new(
         satpoint,
@@ -149,7 +135,7 @@ impl Burn {
         script_pubkey,
         change,
         fee_rate,
-        postage,
+        Target::ExactPostage(burn_amount),
         wallet.chain().network(),
       )
       .build_transaction()?,

tests/wallet/burn.rs

@@ -33,7 +33,7 @@ fn inscriptions_can_be_burned() {
     <span title=burned>🔥</span>
   </dd>
   <dt>value</dt>
-  <dd>9918</dd>
+  <dd>1</dd>
   .*
   <dt>content length</dt>
   <dd>3 bytes</dd>
@@ -116,7 +116,7 @@ fn runic_outputs_are_protected() {
 }
 
 #[test]
-fn cannot_burn_inscriptions_on_large_utxos() {
+fn burns_only_one_sat() {
   let core = mockcore::spawn();
 
   let ord = TestServer::spawn_with_server_args(&core, &[], &[]);
@@ -125,14 +125,45 @@ fn cannot_burn_inscriptions_on_large_utxos() {
 
   core.mine_blocks(1);
 
-  let (inscription, _) = inscribe_with_postage(&core, &ord, Some(10_001));
+  assert_eq!(
+    CommandBuilder::new("wallet balance")
+      .core(&core)
+      .ord(&ord)
+      .run_and_deserialize_output::<Balance>(),
+    Balance {
+      cardinal: 50 * COIN_VALUE,
+      ordinal: 0,
+      runic: None,
+      runes: None,
+      total: 50 * COIN_VALUE,
+    }
+  );
+
+  let (inscription, _) = inscribe_with_postage(&core, &ord, Some(100_000));
 
   CommandBuilder::new(format!("wallet burn --fee-rate 1 {inscription}",))
     .core(&core)
     .ord(&ord)
-    .expected_stderr("error: Cannot burn inscription contained in UTXO exceeding 0.00010000 BTC\n")
-    .expected_exit_code(1)
-    .run_and_extract_stdout();
+    .run_and_deserialize_output::<Send>();
+
+  core.mine_blocks(1);
+
+  // 4 block rewards - 1 burned sat
+  let expected_balance = 4 * 50 * COIN_VALUE - 1;
+
+  assert_eq!(
+    CommandBuilder::new("wallet balance")
+      .core(&core)
+      .ord(&ord)
+      .run_and_deserialize_output::<Balance>(),
+    Balance {
+      cardinal: expected_balance,
+      ordinal: 0,
+      runic: None,
+      runes: None,
+      total: expected_balance,
+    }
+  );
 }
 
 #[test]
@@ -191,30 +222,6 @@ fn cannot_burn_inscription_sharing_utxo_with_another_inscription() {
     .run_and_extract_stdout();
 }
 
-#[test]
-fn cannot_burn_with_excess_postage() {
-  let core = mockcore::spawn();
-
-  let ord = TestServer::spawn_with_server_args(&core, &[], &[]);
-
-  create_wallet(&core, &ord);
-
-  core.mine_blocks(1);
-
-  let (inscription, _) = inscribe(&core, &ord);
-
-  core.mine_blocks(1);
-
-  CommandBuilder::new(format!(
-    "wallet burn --fee-rate 1 {inscription} --postage 10001sat",
-  ))
-  .core(&core)
-  .ord(&ord)
-  .expected_stderr("error: Postage may not exceed 0.00010000 BTC\n")
-  .expected_exit_code(1)
-  .run_and_extract_stdout();
-}
-
 #[test]
 fn json_metadata_can_be_included_when_burning() {
   let core = mockcore::spawn();
@@ -258,7 +265,7 @@ fn json_metadata_can_be_included_when_burning() {
       fee: 138,
       id: inscription,
       output: Some(TxOut {
-        value: Amount::from_sat(9907),
+        value: Amount::from_sat(1),
         script_pubkey,
       }),
       height: 3,
@@ -327,7 +334,7 @@ fn cbor_metadata_can_be_included_when_burning() {
       fee: 138,
       id: inscription,
       output: Some(TxOut {
-        value: Amount::from_sat(9907),
+        value: Amount::from_sat(1),
         script_pubkey,
       }),
       height: 3,