fix: Fix invariant assertion in binary-codec (#2429)

* Fix assertion * Add a test
XRPLF · Aug 9, 2023 · bcc9057 · bcc9057
1 parent 958c97b
commit bcc9057
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Showing 2 changed files with 7 additions and 1 deletion.
diff --git a/packages/ripple-binary-codec/src/serdes/binary-parser.ts b/packages/ripple-binary-codec/src/serdes/binary-parser.ts
@@ -75,7 +75,7 @@ class BinaryParser {
    * @return The number represented by those bytes
    */
   readUIntN(n: number): number {
-    if (0 >= n && n > 4) {
+    if (0 >= n || n > 4) {
       throw new Error('invalid n')
     }
     return this.read(n).reduce((a, b) => (a << 8) | b) >>> 0

diff --git a/packages/ripple-binary-codec/test/binary-parser.test.js b/packages/ripple-binary-codec/test/binary-parser.test.js
@@ -242,6 +242,12 @@ function fieldParsingTests() {
       new Error('Cannot read FieldOrdinal, type_code out of range'),
     )
   })
+  test('readUIntN', () => {
+    const parser = makeParser('0009')
+    expect(parser.readUIntN(2)).toEqual(9)
+    expect(() => parser.readUIntN(-1)).toThrow(new Error('invalid n'))
+    expect(() => parser.readUIntN(5)).toThrow(new Error('invalid n'))
+  })
 }
 
 function assertRecyclable(json, forField) {