refactor: define TrustSet transaction model (#1549)

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

test/models/trustSet.ts

@@ -0,0 +1,66 @@
+import { ValidationError } from 'xrpl-local/common/errors'
+import { verifyTrustSet } from './../../src/models/transactions/trustSet'
+import { assert } from 'chai'
+
+/**
+ * TrustSet Transaction Verification Testing
+ *
+ * Providing runtime verification testing for each specific transaction type
+ */
+describe('TrustSet Transaction Verification', () => {
+    let trustSet
+
+    beforeEach(() => {
+        trustSet = {
+            TransactionType: 'TrustSet',
+            Account: 'rUn84CUYbNjRoTQ6mSW7BVJPSVJNLb1QLo',
+            LimitAmount: {
+                currency: 'XRP',
+                issuer: 'rcXY84C4g14iFp6taFXjjQGVeHqSCh9RX',
+                value: '4329.23'
+            },
+            QualityIn: 1234,
+            QualityOut: 4321,
+        } as any
+    })
+
+    it ('verifies valid TrustSet', () => {
+        assert.doesNotThrow(() => verifyTrustSet(trustSet))
+    })
+
+    it ('throws when LimitAmount is missing', () => {
+        delete trustSet.LimitAmount
+        assert.throws(
+            () => verifyTrustSet(trustSet),
+            ValidationError,
+            'TrustSet: missing field LimitAmount'
+        )
+    })
+
+    it ('throws when LimitAmount is invalid', () => {
+        trustSet.LimitAmount = 1234
+        assert.throws(
+            () => verifyTrustSet(trustSet),
+            ValidationError,
+            'TrustSet: invalid LimitAmount'
+        )
+    })
+
+    it ('throws when QualityIn is not a number', () => {
+        trustSet.QualityIn = '1234'
+        assert.throws(
+            () => verifyTrustSet(trustSet),
+            ValidationError,
+            'TrustSet: QualityIn must be a number'
+        )
+    })
+
+    it ('throws when QualityOut is not a number', () => {
+        trustSet.QualityOut = '4321'
+        assert.throws(
+            () => verifyTrustSet(trustSet),
+            ValidationError,
+            'TrustSet: QualityOut must be a number'
+        )
+    })
+})