Adaptations in Weight Calculation Methods

This update ensure that `@bitcoinerlab/coinselect` takes full advantage of the recent improvements in the `@bitcoinerlab/descriptors` package, particularly the new weight calculation methods. This alignment enhances the performance of coin selection and transaction size estimation since it now relies on smarter caching strategies implemented in `@bitcoinerlab/descriptors`.

It aligns with the recent enhancements and new functionalities in weight calculation methods introduced in `@bitcoinerlab/descriptors` ([PR #32](bitcoinerlab/descriptors#32)).

**Key Changes:**
1. **Package Version and Dependencies:**
   - Upgraded `@bitcoinerlab/coinselect` from version `1.1.0` to `1.2.0`.
   - Updated the dependency on `@bitcoinerlab/descriptors` to version `2.1.0` to leverage the latest enhancements.

2. **Code Refactoring:**
   - Removed local implementations of weight calculations (`inputWeight` and `outputWeight`) and replaced them with the updated methods from `@bitcoinerlab/descriptors`.
   - Simplified and streamlined the code by removing redundant functions and logic, relying on the improved functionalities in the `descriptors` package.

3. **Validation and Dust Calculation Adjustments:**
   - Updated the validation logic to incorporate changes in dust calculation and fee rate validation.
   - Ensured compatibility with the new weight calculation methods in handling UTXOs and transaction outputs.

4. **Test Suite Enhancements:**
   - Revised test cases to align with the updated logic and methods.

Updates and modifications have been appropriately commented and documented within the code.

package.json

@@ -1,6 +1,6 @@
 {
   "name": "@bitcoinerlab/coinselect",
-  "version": "1.1.0",
+  "version": "1.2.0",
   "author": "Jose-Luis Landabaso",
   "license": "MIT",
   "description": "A TypeScript library for Bitcoin transaction management, based on Bitcoin Descriptors for defining inputs and outputs. It facilitates optimal UTXO selection and transaction size calculation.",
@@ -52,6 +52,6 @@
     "regtest-client": "^0.2.1"
   },
   "dependencies": {
-    "@bitcoinerlab/descriptors": "^2.0.3"
+    "@bitcoinerlab/descriptors": "^2.1.0"
   }
 }

src/algos/maxFunds.ts

@@ -3,6 +3,7 @@ import { DUST_RELAY_FEE_RATE, OutputWithValue } from '../index';
 import {
   validateFeeRate,
   validateOutputWithValues,
+  validateDust,
   validatedFeeAndVsize
 } from '../validation';
 import { vsize } from '../vsize';
@@ -38,7 +39,8 @@ export function maxFunds({
   dustRelayFeeRate?: number;
 }) {
   validateOutputWithValues(utxos);
-  targets.length === 0 || validateOutputWithValues(targets);
+  if (targets.length) validateOutputWithValues(targets);
+  validateDust(targets);
   validateFeeRate(feeRate);
   validateFeeRate(dustRelayFeeRate);
 

src/coinselect.ts

@@ -8,8 +8,7 @@ import {
 } from './validation';
 import { addUntilReach } from './algos/addUntilReach';
 import { avoidChange } from './algos/avoidChange';
-import { inputWeight } from './vsize';
-import { isSegwitTx } from './segwit';
+import { isSegwitTx } from './vsize';
 
 // order by descending value, minus the inputs approximate fee
 function utxoTransferredValue(
@@ -19,7 +18,12 @@ function utxoTransferredValue(
 ) {
   return (
     outputAndValue.value -
-    (feeRate * inputWeight(outputAndValue.output, isSegwitTx)) / 4
+    (feeRate *
+      outputAndValue.output.inputWeight(
+        isSegwitTx,
+        'DANGEROUSLY_USE_FAKE_SIGNATURES'
+      )) /
+      4
   );
 }
 

src/dust.ts

@@ -1,6 +1,4 @@
 import type { OutputInstance } from '@bitcoinerlab/descriptors';
-import { inputWeight, outputWeight } from './vsize';
-import { isSegwit } from './segwit';
 import { DUST_RELAY_FEE_RATE } from './index';
 
 /**
@@ -52,11 +50,17 @@ export function dustThreshold(
    */
   dustRelayFeeRate: number = DUST_RELAY_FEE_RATE
 ) {
-  const isSegwitOutput = isSegwit(output);
+  const isSegwitOutput = output.isSegwit();
+  if (isSegwitOutput === undefined) throw new Error(`Unknown output type`);
   return Math.ceil(
     dustRelayFeeRate *
       Math.ceil(
-        (outputWeight(output) + inputWeight(output, isSegwitOutput)) / 4
+        (output.outputWeight() +
+          output.inputWeight(
+            isSegwitOutput,
+            'DANGEROUSLY_USE_FAKE_SIGNATURES'
+          )) /
+          4
       )
   );
 }

src/index.ts

@@ -11,7 +11,6 @@ import type { OutputInstance } from '@bitcoinerlab/descriptors';
 export { coinselect } from './coinselect';
 export { vsize } from './vsize';
 export { dustThreshold } from './dust';
-export { inputWeight, outputWeight } from './vsize';
 export { maxFunds } from './algos/maxFunds';
 export { addUntilReach } from './algos/addUntilReach';
 export { avoidChange } from './algos/avoidChange';

src/validation.ts

@@ -39,9 +39,13 @@ export function validatedFeeAndVsize(
     targets.map(t => t.output)
   );
   const finalFeeRate = fee / vsizeResult;
-  if (finalFeeRate < feeRate)
+  // Don't compare fee rates because values are picked based on comparing fees (multiplications)
+  // Don't mix * / operators:
+  // F.ex.: 100/27 !== 100*(1/27)
+  // Instead, compare final fee
+  if (fee < Math.ceil(vsizeResult * feeRate))
     throw new Error(
-      `Final fee rate ${finalFeeRate} lower than required ${feeRate}`
+      `Final fee ${fee} lower than required ${Math.ceil(vsizeResult * feeRate)}`
     );
   validateFeeRate(finalFeeRate);
   return { fee, vsize: vsizeResult };