diff --git a/test/psbt.js b/test/psbt.js
index ecb78ab..cd45c1e 100644
--- a/test/psbt.js
+++ b/test/psbt.js
@@ -154,6 +154,20 @@ describe(`Psbt`, () => {
         psbt.getFeeRate()
       }, new RegExp('PSBT must be finalized to calculate fee rate'))
 
+      const pubkey = Buffer.from(
+        '029583bf39ae0a609747ad199addd634fa6108559d6c5cd39b4c2183f1ab96e07f',
+        'hex',
+      )
+      assert.strictEqual(psbt.validateSignatures(0), true)
+      assert.strictEqual(psbt.validateSignatures(0, pubkey), true)
+      assert.throws(() => {
+        pubkey[32] = 42
+        psbt.validateSignatures(0, pubkey)
+      }, new RegExp('No signatures for this pubkey'))
+      assert.throws(() => {
+        psbt.validateSignatures(42)
+      }, new RegExp('No signatures to validate'))
+
       psbt.finalizeAllInputs()
 
       assert.strictEqual(psbt.toBase64(), f.result)
@@ -246,6 +260,54 @@ describe(`Psbt`, () => {
     })
   })
 
+  describe('signAsync', () => {
+    fixtures.signInput.checks.forEach(f => {
+      if (f.description === 'checks the input exists') return
+      it(f.description, async () => {
+        const psbtThatShouldsign = Psbt.fromBase64(f.shouldSign.psbt)
+        assert.doesNotReject(async () => {
+          await psbtThatShouldsign.signAsync(
+            ECPair.fromWIF(f.shouldSign.WIF),
+          )
+        })
+
+        const psbtThatShouldThrow = Psbt.fromBase64(f.shouldThrow.psbt)
+        assert.rejects(async () => {
+          await psbtThatShouldThrow.signAsync(
+            ECPair.fromWIF(f.shouldThrow.WIF),
+          )
+        }, new RegExp('No inputs were signed'))
+        assert.rejects(async () => {
+          await psbtThatShouldThrow.signAsync()
+        }, new RegExp('Need Signer to sign input'))
+      })
+    })
+  })
+
+  describe('sign', () => {
+    fixtures.signInput.checks.forEach(f => {
+      if (f.description === 'checks the input exists') return
+      it(f.description, () => {
+        const psbtThatShouldsign = Psbt.fromBase64(f.shouldSign.psbt)
+        assert.doesNotThrow(() => {
+          psbtThatShouldsign.sign(
+            ECPair.fromWIF(f.shouldSign.WIF),
+          )
+        })
+
+        const psbtThatShouldThrow = Psbt.fromBase64(f.shouldThrow.psbt)
+        assert.throws(() => {
+          psbtThatShouldThrow.sign(
+            ECPair.fromWIF(f.shouldThrow.WIF),
+          )
+        }, new RegExp('No inputs were signed'))
+        assert.throws(() => {
+          psbtThatShouldThrow.sign()
+        }, new RegExp('Need Signer to sign input'))
+      })
+    })
+  })
+
   describe('fromTransaction', () => {
     fixtures.fromTransaction.forEach(f => {
       it('Creates the expected PSBT from a transaction buffer', () => {
@@ -363,6 +425,44 @@ describe(`Psbt`, () => {
     })
   })
 
+  describe('create 1-to-1 transaction', () => {
+    const alice = ECPair.fromWIF('L2uPYXe17xSTqbCjZvL2DsyXPCbXspvcu5mHLDYUgzdUbZGSKrSr')
+    const psbt = new Psbt()
+    psbt.addInput({
+      hash: '7d067b4a697a09d2c3cff7d4d9506c9955e93bff41bf82d439da7d030382bc3e',
+      index: 0,
+      nonWitnessUtxo: Buffer.from(
+        '0200000001f9f34e95b9d5c8abcd20fc5bd4a825d1517be62f0f775e5f36da944d9' +
+        '452e550000000006b483045022100c86e9a111afc90f64b4904bd609e9eaed80d48' +
+        'ca17c162b1aca0a788ac3526f002207bb79b60d4fc6526329bf18a77135dc566020' +
+        '9e761da46e1c2f1152ec013215801210211755115eabf846720f5cb18f248666fec' +
+        '631e5e1e66009ce3710ceea5b1ad13ffffffff01905f0100000000001976a9148bb' +
+        'c95d2709c71607c60ee3f097c1217482f518d88ac00000000',
+        'hex',
+      ),
+      sighashType: 1,
+    })
+    psbt.addOutput({
+      address: '1KRMKfeZcmosxALVYESdPNez1AP1mEtywp',
+      value: 80000
+    })
+    psbt.signInput(0, alice)
+    assert.throws(() => {
+      psbt.setVersion(3)
+    }, new RegExp('Can not modify transaction, signatures exist.'))
+    psbt.validateSignatures(0)
+    psbt.finalizeAllInputs()
+    assert.strictEqual(
+      psbt.extractTransaction().toHex(),
+      '02000000013ebc8203037dda39d482bf41ff3be955996c50d9d4f7cfc3d2097a694a7' +
+      'b067d000000006b483045022100931b6db94aed25d5486884d83fc37160f37f3368c0' +
+      'd7f48c757112abefec983802205fda64cff98c849577026eb2ce916a50ea70626a766' +
+      '9f8596dd89b720a26b4d501210365db9da3f8a260078a7e8f8b708a1161468fb2323f' +
+      'fda5ec16b261ec1056f455ffffffff0180380100000000001976a914ca0d36044e0dc' +
+      '08a22724efa6f6a07b0ec4c79aa88ac00000000',
+    )
+  })
+
   describe('Method return types', () => {
     it('fromTransaction returns Psbt type (not base class)', () => {
       const psbt = Psbt.fromTransaction(Buffer.from([2,0,0,0,0,0,0,0,0,0]));