From a250807918b787049f041d7286d9f0ec0ec66b70 Mon Sep 17 00:00:00 2001
From: Brian Mancini <bmancini@gmail.com>
Date: Sun, 3 Mar 2019 18:03:13 -0500
Subject: [PATCH] Adding additional tests to prefix decoding

---
 src/decoder.js      | 16 +++++++----
 src/decoder.spec.js | 70 +++++++++++++++++++++++++++++++++++++++------
 2 files changed, 72 insertions(+), 14 deletions(-)

diff --git a/src/decoder.js b/src/decoder.js
index 059a536..61f2c66 100644
--- a/src/decoder.js
+++ b/src/decoder.js
@@ -131,20 +131,26 @@ function parsePrefix(prefix) {
   let network = '';
   let amount = '';
   let multiplier;
-  let parsingNetwork = true;
+  let hasNetwork = false;
+  let hasAmount = false;
 
   for (let i = 2; i < prefix.length; i++) {
     let charCode = prefix.charCodeAt(i);
 
-    if (parsingNetwork) {
+    if (!hasNetwork) {
       if (charCode >= 97 && charCode <= 122) network += prefix[i];
-      if (charCode >= 48 && charCode <= 57) parsingNetwork = false;
+      else hasNetwork = true;
     }
 
-    if (!parsingNetwork) {
-      if (multiplier !== undefined) throw new Error('Invalid prefix');
+    if (hasNetwork && !hasAmount) {
       if (charCode >= 48 && charCode <= 57) amount += prefix[i];
+      else if (amount) hasAmount = true;
+      else throw new Error('Invalid amount');
+    }
+
+    if (hasAmount) {
       if (charCode >= 97 && charCode <= 122) multiplier = prefix[i];
+      else throw new Error('Invalid character');
     }
   }
 
diff --git a/src/decoder.spec.js b/src/decoder.spec.js
index b489feb..0186df4 100644
--- a/src/decoder.spec.js
+++ b/src/decoder.spec.js
@@ -10,10 +10,64 @@ describe('decoder', () => {
     expect(() => decoder.decode(input)).to.throw(/Invalid checksum/);
   });
 
-  it('must fail if prefix does not start with ln');
-  it('must fail if unknown network');
-  it('must fail if amount contains non-digit');
-  it('must fail if amount contains invalid multiplier');
+  it('must fail if prefix does not start with ln', () => {
+    let input = bech32.encode('bad', bech32.toWords('test'));
+    expect(() => decoder.decode(input)).to.throw(/Invalid prefix/);
+  });
+  it('must fail if unknown network', () => {
+    let input = bech32.encode('lnbad1', bech32.toWords('test'));
+    expect(() => decoder.decode(input)).to.throw(/Invalid network/);
+  });
+  it('must fail if amount contains non-digit', () => {
+    let input = bech32.encode('lnbc1&m', bech32.toWords('test'));
+    expect(() => decoder.decode(input)).to.throw(/Invalid character/);
+  });
+  it('must fail if multiplier contains non-digit', () => {
+    let input = bech32.encode('lnbc1m&', bech32.toWords('test'));
+    expect(() => decoder.decode(input)).to.throw(/Invalid character/);
+  });
+  it('must fail if amount contains invalid amount', () => {
+    let input = bech32.encode('lnbc0m', bech32.toWords('test'));
+    expect(() => decoder.decode(input)).to.throw(/Invalid amount/);
+  });
+  it('must fail when multiplier without amount', () => {
+    let input = bech32.encode('lnbcm', bech32.toWords('test'));
+    expect(() => decoder.decode(input)).to.throw(/Invalid network/);
+  });
+  it('must fail if amount contains invalid multiplier', () => {
+    let input = bech32.encode('lnbc1a', bech32.toWords('test'));
+    expect(() => decoder.decode(input)).to.throw(/Invalid multiplier/);
+  });
+  it('should have no amount when amount is empty', () => {
+    let input = 'lnbc1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jshwlglv23cytkzvq8ld39drs8sq656yh2zn0aevrwu6uqctaklelhtpjnmgjdzmvwsh0kuxuwqf69fjeap9m5mev2qzpp27xfswhs5vgqmn9xzq'; // prettier-ignore
+    let result = decoder.decode(input);
+    expect(result.amount).to.be.null;
+  });
+  it('should have correct amount with pico multiplier', () => {
+    let input = 'lnbc1p1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jshz8a9p67cuw60898ljqx55lt5hu8yy6nr4rkpsjj69uwzcgsgjwytn65ftnuzsw3fs95aw3pvcfedxzzh34u089hjwrzjl757zw9hxcp0n43t8'; // prettier-ignore
+    let result = decoder.decode(input);
+    expect(result.amount).to.equal(0.000000000001);
+  });
+  it('should have correct amount with nano multiplier', () => {
+    let input = 'lnbc1n1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsydccnehd6uwnnkpk3v94mfeun6rk025yygw0l73usy93snxzwmmhzqxpu2nv80dp2hz47y8tk8znv3mnaez5lvhznfws500cp8f43ucp00ns2d'; // prettier-ignore
+    let result = decoder.decode(input);
+    expect(result.amount).to.equal(0.000000001);
+  });
+  it('should have correct amount with micro multiplier', () => {
+    let input = 'lnbc1u1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jssz5kxlujxj66rcfq6w2ye7dr27u3unumw6wkrs3r9795lrwzallswnvsa0l6dfqm8rzmquv20dqj5zv48n352qfwqtw8572vdha9f0spm5lkzk'; // prettier-ignore
+    let result = decoder.decode(input);
+    expect(result.amount).to.equal(0.000001);
+  });
+  it('should have correct amount with milli multiplier', () => {
+    let input = 'lnbc1m1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4js6qu20kendkn4qgalrnmcwmnffvswt0clnlfeuqkcdenpttsqynh3fl37rqrvc2p8y80jxcyz470ur69jh2ugfcdgjyu0l0mmh0ja2vcpzgn39l'; //prettier-ignore
+    let result = decoder.decode(input);
+    expect(result.amount).to.equal(0.001);
+  });
+  it('should have correct amount with no multiplier', () => {
+    let input = 'lnbc11pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsn4qy2qvfxxml5e6mnynqy9mhz4x4vqzqtnwp92fw6xrz5rvspm98u6jg0slh85kq7934eh86tg2up7h5cxhyf229gsrrtstfw5zcheqqm2ezmv'; // prettier-ignore
+    let result = decoder.decode(input);
+    expect(result.amount).to.equal(1);
+  });
 
   it('must fail if the signature is invalid');
 
@@ -26,11 +80,9 @@ describe('decoder', () => {
     'must use n field to validate signature instead of performing signature recovery if a valid n is provided'
   );
 
-  describe('it vectors', () => {
+  describe('test vectors', () => {
     const sha256 = crypto.createHash('sha256');
-    sha256.update(
-      'One piece of chocolate cake, one icecream cone, one pickle, one slice of swiss cheese, one slice of salami, one lollypop, one piece of cherry pie, one sausage, one cupcake, and one slice of watermelon'
-    );
+    sha256.update('One piece of chocolate cake, one icecream cone, one pickle, one slice of swiss cheese, one slice of salami, one lollypop, one piece of cherry pie, one sausage, one cupcake, and one slice of watermelon'); // prettier-ignore
     const hashDescription = sha256.digest();
 
     const pubkey = Buffer.from(
@@ -278,7 +330,7 @@ describe('decoder', () => {
     });
   });
 
-  describe('additional it vectors', () => {
+  describe('additional test vectors', () => {
     it('send 0.02 BTC, on simnet', () => {
       let input =
         'lnsb20m1pd3dfr9pp5s90vpp5a7sxzd4zenxxesvfge73nqslj4h7zn29059hgyp7jdvjqdqqcqzysqngw58lu63trytwj7ktx7vasdutvvan7paq5qrgjj6wg065qzr8pv8p6q7kcdeg0kdpek09gc7xf6y972gy7t3pl6gtcqww440znz6gpfec4kj';