README/tests: add BIP173/BIP16 SegWit address examples

Author: dcousens

README.md

@@ -98,6 +98,10 @@ Some examples interact (via HTTPS) with a 3rd Party Blockchain Provider (3PBP).
 - [Generate an address from a SHA256 hash](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L19)
 - [Import an address via WIF](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L29)
 - [Generate a 2-of-3 multisig P2SH address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L36)
+- [Generate a SegWit address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js:61)
+- [Generate a SegWit address (via P2SH)](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js:50)
+- [Generate a SegWit 3-of-4 multisig address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js:85)
+- [Generate a SegWit 2-of-2 multisig address (via P2SH)](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js:71)
 - [Support the retrieval of transactions for an address (3rd party blockchain)](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L52)
 - [Generate a Testnet address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L73)
 - [Generate a Litecoin address](https://github.com/bitcoinjs/bitcoinjs-lib/blob/ae8422d/test/integration/addresses.js#L83)

test/integration/addresses.js

@@ -38,9 +38,7 @@ describe('bitcoinjs-lib (addresses)', function () {
       '026477115981fe981a6918a6297d9803c4dc04f328f22041bedff886bbc2962e01',
       '02c96db2302d19b43d4c69368babace7854cc84eb9e061cde51cfa77ca4a22b8b9',
       '03c6103b3b83e4a24a0e33a4df246ef11772f9992663db0c35759a5e2ebf68d8e9'
-    ].map(function (hex) {
-      return Buffer.from(hex, 'hex')
-    })
+    ].map(function (hex) { return Buffer.from(hex, 'hex') })
 
     var redeemScript = bitcoin.script.multisig.output.encode(2, pubKeys) // 2 of 3
     var scriptPubKey = bitcoin.script.scriptHash.output.encode(bitcoin.crypto.hash160(redeemScript))
@@ -49,6 +47,56 @@ describe('bitcoinjs-lib (addresses)', function () {
     assert.strictEqual(address, '36NUkt6FWUi3LAWBqWRdDmdTWbt91Yvfu7')
   })
 
+  it('can generate a SegWit address', function () {
+    var keyPair = bitcoin.ECPair.fromWIF('Kxr9tQED9H44gCmp6HAdmemAzU3n84H3dGkuWTKvE23JgHMW8gct')
+    var pubKey = keyPair.getPublicKeyBuffer()
+
+    var scriptPubKey = bitcoin.script.witnessPubKeyHash.output.encode(bitcoin.crypto.hash160(pubKey))
+    var address = bitcoin.address.fromOutputScript(scriptPubKey)
+
+    assert.strictEqual(address, 'bc1qt97wqg464zrhnx23upykca5annqvwkwujjglky')
+  })
+
+  it('can generate a SegWit address (via P2SH)', function () {
+    var keyPair = bitcoin.ECPair.fromWIF('Kxr9tQED9H44gCmp6HAdmemAzU3n84H3dGkuWTKvE23JgHMW8gct')
+    var pubKey = keyPair.getPublicKeyBuffer()
+
+    var witnessScript = bitcoin.script.witnessPubKeyHash.output.encode(bitcoin.crypto.hash160(pubKey))
+    var scriptPubKey = bitcoin.script.scriptHash.output.encode(bitcoin.crypto.hash160(witnessScript))
+    var address = bitcoin.address.fromOutputScript(scriptPubKey)
+
+    assert.strictEqual(address, '34AgLJhwXrvmkZS1o5TrcdeevMt22Nar53')
+  })
+
+  it('can generate a SegWit 3-of-4 multisig address', function () {
+    var pubKeys = [
+      '026477115981fe981a6918a6297d9803c4dc04f328f22041bedff886bbc2962e01',
+      '02c96db2302d19b43d4c69368babace7854cc84eb9e061cde51cfa77ca4a22b8b9',
+      '023e4740d0ba639e28963f3476157b7cf2fb7c6fdf4254f97099cf8670b505ea59',
+      '03c6103b3b83e4a24a0e33a4df246ef11772f9992663db0c35759a5e2ebf68d8e9'
+    ].map(function (hex) { return Buffer.from(hex, 'hex') })
+
+    var witnessScript = bitcoin.script.multisig.output.encode(3, pubKeys) // 3 of 4
+    var scriptPubKey = bitcoin.script.witnessScriptHash.output.encode(bitcoin.crypto.sha256(witnessScript))
+    var address = bitcoin.address.fromOutputScript(scriptPubKey)
+
+    assert.strictEqual(address, 'bc1q75f6dv4q8ug7zhujrsp5t0hzf33lllnr3fe7e2pra3v24mzl8rrqtp3qul')
+  })
+
+  it('can generate a SegWit 2-of-2 multisig address (via P2SH)', function () {
+    var pubKeys = [
+      '026477115981fe981a6918a6297d9803c4dc04f328f22041bedff886bbc2962e01',
+      '02c96db2302d19b43d4c69368babace7854cc84eb9e061cde51cfa77ca4a22b8b9'
+    ].map(function (hex) { return Buffer.from(hex, 'hex') })
+
+    var witnessScript = bitcoin.script.multisig.output.encode(2, pubKeys) // 2 of 2
+    var redeemScript = bitcoin.script.witnessScriptHash.output.encode(bitcoin.crypto.sha256(witnessScript))
+    var scriptPubKey = bitcoin.script.scriptHash.output.encode(bitcoin.crypto.hash160(redeemScript))
+    var address = bitcoin.address.fromOutputScript(scriptPubKey)
+
+    assert.strictEqual(address, '3P4mrxQfmExfhxqjLnR2Ah4WES5EB1KBrN')
+  })
+
   it('can support the retrieval of transactions for an address (3rd party blockchain)', function (done) {
     var keyPair = bitcoin.ECPair.makeRandom()
     var address = keyPair.getAddress()