Add tests for low R signing

test/ecpair.js

@@ -259,4 +259,26 @@ describe('ECPair', () => {
       }))
     })
   })
+  describe('optional low R signing', () => {
+    const sig = Buffer.from('95a6619140fca3366f1d3b013b0367c4f86e39508a50fdce' +
+      'e5245fbb8bd60aa6086449e28cf15387cf9f85100bfd0838624ca96759e59f65c10a00' +
+      '16b86f5229', 'hex')
+    const sigLowR = Buffer.from('6a2660c226e8055afad317eeba918a304be79208d505' +
+      '3bc5ea4a5e4c5892b4a061c717c5284ae5202d721c0e49b4717b79966280906b1d3b52' +
+      '95d1fdde963c35', 'hex')
+    const lowRKeyPair = ECPair.fromWIF('L3nThUzbAwpUiBAjR5zCu66ybXSPMr2zZ3ikp' +
+      'ScpTPiYTxBynfZu')
+    const dataToSign = Buffer.from('b6c5c548a7f6164c8aa7af5350901626ebd69f9ae' +
+      '2c1ecf8871f5088ec204cfe', 'hex')
+
+    it('signs with normal R by default', () => {
+      const signed = lowRKeyPair.sign(dataToSign)
+      assert.deepStrictEqual(sig, signed)
+    })
+
+    it('signs with low R when true is passed', () => {
+      const signed = lowRKeyPair.sign(dataToSign, true)
+      assert.deepStrictEqual(sigLowR, signed)
+    })
+  })
 })