refactor: define TicketCreate transaction model (#1547)

- Defines a TypeScript type for TicketCreate
- Provides an optional function to users for verifying a TicketCreate instance at runtime: verifyTicketCreate()
- Adds tests for verifyTicketCreate()

test/models/ticketCreate.ts

@@ -0,0 +1,69 @@
+import { ValidationError } from 'xrpl-local/common/errors'
+import { verifyTicketCreate } from './../../src/models/transactions/ticketCreate'
+import { assert } from 'chai'
+
+/**
+ * TicketCreate Transaction Verification Testing
+ *
+ * Providing runtime verification testing for each specific transaction type
+ */
+describe('TicketCreate Transaction Verification', () => {
+    let ticketCreate
+
+    beforeEach(() => {
+        ticketCreate = {
+            TransactionType: 'TicketCreate',
+            Account: 'rUn84CUYbNjRoTQ6mSW7BVJPSVJNLb1QLo',
+            TicketCount: 150,
+        } as any
+    })
+
+    it ('verifies valid TicketCreate', () => {
+        assert.doesNotThrow(() => verifyTicketCreate(ticketCreate))
+    })
+
+    it ('throws when TicketCount is missing', () => {
+        delete ticketCreate.TicketCount
+        assert.throws(
+            () => verifyTicketCreate(ticketCreate),
+            ValidationError,
+            'TicketCreate: missing field TicketCount'
+        )
+    })
+
+    it ('throws when TicketCount is not a number', () => {
+        ticketCreate.TicketCount = '150'
+        assert.throws(
+            () => verifyTicketCreate(ticketCreate),
+            ValidationError,
+            'TicketCreate: TicketCount must be a number'
+        )
+    })
+
+    it ('throws when TicketCount is not an integer', () => {
+        ticketCreate.TicketCount = 12.5
+        assert.throws(
+            () => verifyTicketCreate(ticketCreate),
+            ValidationError,
+            'TicketCreate: TicketCount must be an integer from 1 to 250'
+        )
+    })
+
+    it ('throws when TicketCount is < 1', () => {
+        ticketCreate.TicketCount = 0
+        assert.throws(
+            () => verifyTicketCreate(ticketCreate),
+            ValidationError,
+            'TicketCreate: TicketCount must be an integer from 1 to 250'
+        )
+    })
+
+    it ('throws when TicketCount is > 250', () => {
+        ticketCreate.TicketCount = 251
+        assert.throws(
+            () => verifyTicketCreate(ticketCreate),
+            ValidationError,
+            'TicketCreate: TicketCount must be an integer from 1 to 250'
+        )
+    })
+})