fix: resolve OfferCancel merge issues (#1546)

* fix: resolve OfferCancel git issues

test/models/checkCancel.ts

@@ -7,7 +7,7 @@ import { assert } from 'chai'
  *
  * Providing runtime verification testing for each specific transaction type
  */
-describe('Transaction Verification', function () {
+describe('CheckCancel Transaction Verification', function () {
 
     it (`verifies valid CheckCancel`, () => {
         const validCheckCancel = {

test/models/offerCancel.ts

@@ -0,0 +1,53 @@
+import { ValidationError } from 'xrpl-local/common/errors'
+import { verifyOfferCancel } from './../../src/models/transactions/offerCancel'
+import { assert } from 'chai'
+
+/**
+ * OfferCancel Transaction Verification Testing
+ *
+ * Providing runtime verification testing for each specific transaction type
+ */
+describe('OfferCancel Transaction Verification', function () {
+   let offer
+   
+   beforeEach(() => {
+       offer = {
+            Account: "rnKiczmiQkZFiDES8THYyLA2pQohC5C6EF",
+            Fee: "10",
+            LastLedgerSequence: 65477334,
+            OfferSequence: 60797528,
+            Sequence: 60797535,
+            SigningPubKey: "0361BFD43D1EEA54B77CC152887312949EBF052997FBFFCDAF6F2653164B55B21...",
+            TransactionType: "OfferCancel",
+            TxnSignature: "30450221008C43BDCFC68B4793857CA47DF454C07E5B45D3F80E8E6785CAB9292...",
+            date: "2021-08-06T21:04:11Z"
+        } as any
+   })
+
+    it (`verifies valid OfferCancel`, () => {        
+        assert.doesNotThrow(() => verifyOfferCancel(offer))        
+    })
+
+    it (`verifies valid OfferCancel with flags`, () => {
+        offer.Flags = 2147483648
+        assert.doesNotThrow(() => verifyOfferCancel(offer))
+    })
+
+    it (`throws w/ OfferSequence must be a number`, () => {
+        offer.OfferSequence = '99'
+        assert.throws(
+            () => verifyOfferCancel(offer),
+            ValidationError,
+            "OfferCancel: OfferSequence must be a number"
+        )
+    })
+
+    it (`throws w/ missing OfferSequence`, () => {
+        delete offer.OfferSequence
+        assert.throws(
+            () => verifyOfferCancel(offer),
+            ValidationError,
+            "OfferCancel: missing field OfferSequence"
+        )
+    })
+})