fix: add integer check for UInt types in binary codec (#3179)

Author: mvadari

packages/ripple-binary-codec/HISTORY.md

@@ -4,6 +4,7 @@
 
 ### Fixed
 * Fix STNumber serialization logic to work with large mantissa scale [10^18, 10^19-1].
+* Error if a decimal is passed into a `UInt`-typed field.
 
 ## 2.6.0 (2025-12-16)
 

packages/ripple-binary-codec/src/types/uint-16.ts

@@ -29,15 +29,15 @@ class UInt16 extends UInt {
       return val
     }
 
-    if (typeof val === 'number') {
+    if (typeof val === 'number' && Number.isInteger(val)) {
       UInt16.checkUintRange(val, 0, 0xffff)
 
       const buf = new Uint8Array(UInt16.width)
       writeUInt16BE(buf, val, 0)
       return new UInt16(buf)
     }
 
-    throw new Error('Can not construct UInt16 with given value')
+    throw new Error('Cannot construct UInt16 from given value')
   }
 
   /**

packages/ripple-binary-codec/src/types/uint-32.ts

@@ -37,7 +37,7 @@ class UInt32 extends UInt {
       return new UInt32(buf)
     }
 
-    if (typeof val === 'number') {
+    if (typeof val === 'number' && Number.isInteger(val)) {
       UInt32.checkUintRange(val, 0, 0xffffffff)
       writeUInt32BE(buf, val, 0)
       return new UInt32(buf)

packages/ripple-binary-codec/src/types/uint-64.ts

@@ -53,7 +53,7 @@ class UInt64 extends UInt {
 
     let buf = new Uint8Array(UInt64.width)
 
-    if (typeof val === 'number') {
+    if (typeof val === 'number' && Number.isInteger(val)) {
       if (val < 0) {
         throw new Error('value must be an unsigned integer')
       }

packages/ripple-binary-codec/src/types/uint-8.ts

@@ -28,7 +28,7 @@ class UInt8 extends UInt {
       return val
     }
 
-    if (typeof val === 'number') {
+    if (typeof val === 'number' && Number.isInteger(val)) {
       UInt8.checkUintRange(val, 0, 0xff)
 
       const buf = new Uint8Array(UInt8.width)

packages/ripple-binary-codec/test/uint.test.ts

@@ -1,4 +1,4 @@
-import { UInt8, UInt64 } from '../src/types'
+import { UInt8, UInt16, UInt32, UInt64 } from '../src/types'
 import { encode, decode } from '../src'
 
 const binary =
@@ -195,3 +195,109 @@ it('UInt64 is parsed as base 10 for MPT amounts', () => {
   expect(typeof decodedToken.MPTAmount).toBe('string')
   expect(decodedToken.MPTAmount).toBe('100')
 })
+
+describe('UInt decimal validation', () => {
+  describe('UInt8', () => {
+    it('should throw error when passed a decimal number', () => {
+      expect(() => UInt8.from(1.5)).toThrow(
+        new Error('Cannot construct UInt8 from given value'),
+      )
+    })
+
+    it('should throw error when passed a negative decimal', () => {
+      expect(() => UInt8.from(-1.5)).toThrow(
+        new Error('Cannot construct UInt8 from given value'),
+      )
+    })
+
+    it('should throw error when passed a small decimal', () => {
+      expect(() => UInt8.from(0.1)).toThrow(
+        new Error('Cannot construct UInt8 from given value'),
+      )
+    })
+
+    it('should accept valid integer values', () => {
+      expect(() => UInt8.from(0)).not.toThrow()
+      expect(() => UInt8.from(1)).not.toThrow()
+      expect(() => UInt8.from(255)).not.toThrow()
+    })
+  })
+
+  describe('UInt16', () => {
+    it('should throw error when passed a decimal number', () => {
+      expect(() => UInt16.from(100.5)).toThrow(
+        new Error('Cannot construct UInt16 from given value'),
+      )
+    })
+
+    it('should throw error when passed a negative decimal', () => {
+      expect(() => UInt16.from(-100.5)).toThrow(
+        new Error('Cannot construct UInt16 from given value'),
+      )
+    })
+
+    it('should throw error when passed a small decimal', () => {
+      expect(() => UInt16.from(0.001)).toThrow(
+        new Error('Cannot construct UInt16 from given value'),
+      )
+    })
+
+    it('should accept valid integer values', () => {
+      expect(() => UInt16.from(0)).not.toThrow()
+      expect(() => UInt16.from(1000)).not.toThrow()
+      expect(() => UInt16.from(65535)).not.toThrow()
+    })
+  })
+
+  describe('UInt32', () => {
+    it('should throw error when passed a decimal number', () => {
+      expect(() => UInt32.from(1000.5)).toThrow(
+        new Error('Cannot construct UInt32 from given value'),
+      )
+    })
+
+    it('should throw error when passed a negative decimal', () => {
+      expect(() => UInt32.from(-1000.5)).toThrow(
+        new Error('Cannot construct UInt32 from given value'),
+      )
+    })
+
+    it('should throw error when passed a small decimal', () => {
+      expect(() => UInt32.from(0.0001)).toThrow(
+        new Error('Cannot construct UInt32 from given value'),
+      )
+    })
+
+    it('should accept valid integer values', () => {
+      expect(() => UInt32.from(0)).not.toThrow()
+      expect(() => UInt32.from(100000)).not.toThrow()
+      expect(() => UInt32.from(4294967295)).not.toThrow()
+    })
+  })
+
+  describe('UInt64', () => {
+    it('should throw error when passed a decimal number', () => {
+      expect(() => UInt64.from(10000.5)).toThrow(
+        new Error('Cannot construct UInt64 from given value'),
+      )
+    })
+
+    it('should throw error when passed a negative decimal', () => {
+      expect(() => UInt64.from(-10000.5)).toThrow(
+        new Error('Cannot construct UInt64 from given value'),
+      )
+    })
+
+    it('should throw error when passed a small decimal', () => {
+      expect(() => UInt64.from(0.00001)).toThrow(
+        new Error('Cannot construct UInt64 from given value'),
+      )
+    })
+
+    it('should accept valid integer values', () => {
+      expect(() => UInt64.from(0)).not.toThrow()
+      expect(() => UInt64.from(1000000)).not.toThrow()
+      expect(() => UInt64.from(BigInt('9223372036854775807'))).not.toThrow()
+    })
+  })
+})

packages/xrpl/test/integration/transactions/lendingProtocol.test.ts

@@ -309,7 +309,7 @@ describe('Lending Protocol IT', () => {
         Account: loanBrokerWallet.address,
         LoanBrokerID: loanBrokerObjectId,
         PrincipalRequested: '100000',
-        InterestRate: 0.1,
+        InterestRate: 0,
         Counterparty: borrowerWallet.address,
         PaymentTotal: 1,
       }