fix(cip2): computeSelectionLimit constraint logic error

Author: mkazlauskas

Diff for: packages/cip2/src/selectionConstraints.ts

@@ -67,7 +67,7 @@ const getTxSize = (tx: CSL.Transaction) => tx.to_bytes().length;
  * that adjust selection based on selection limit. RRRI implementation uses this after selecting all the inputs
  * and throws MaximumInputCountExceeded if the constraint returns a limit higher than number of selected utxo.
  *
- * @returns {ComputeSelectionLimit} constraint that returns txSize <= maxTxSize ? utxo[].length : utxo[].length+1
+ * @returns {ComputeSelectionLimit} constraint that returns txSize <= maxTxSize ? utxo[].length : utxo[].length-1
  */
 export const computeSelectionLimit =
   (maxTxSize: ProtocolParametersRequiredByInputSelection['maxTxSize'], buildTx: BuildTx): ComputeSelectionLimit =>
@@ -77,7 +77,7 @@ export const computeSelectionLimit =
     if (txSize <= maxTxSize) {
       return selectionSkeleton.inputs.size;
     }
-    return selectionSkeleton.inputs.size + 1;
+    return selectionSkeleton.inputs.size - 1;
   };
 
 export const defaultSelectionConstraints = ({

Diff for: packages/cip2/test/selectionConstraints.test.ts

@@ -90,7 +90,7 @@ describe('defaultSelectionConstraints', () => {
         protocolParameters
       });
       expect(await constraints.computeSelectionLimit({ inputs: new Set([1, 2]) as any } as SelectionSkeleton)).toEqual(
-        3
+        1
       );
     });
   });