add new test vector for ln invoice from bolt11

return error tuple instead of crashing when decoding a ln invoice with
sub msat in amount

new test vectors are copied from lightning/bolts#736

Author: kafaichoi

lib/lightning_network/invoice.ex

@@ -581,9 +581,15 @@ defmodule Bitcoinex.LightningNetwork.Invoice do
     case result do
       {:ok, amount_in_bitcoin} ->
         amount_msat_dec = D.mult(amount_in_bitcoin, @milli_satoshi_per_bitcoin)
-        amount_msat = D.to_integer(amount_msat_dec)
+        rounded_amount_msat_dec = D.round(amount_msat_dec)
 
-        {:ok, amount_msat}
+        case Decimal.equal?(rounded_amount_msat_dec, amount_msat_dec) do
+          true ->
+            {:ok, D.to_integer(rounded_amount_msat_dec)}
+
+          false ->
+            {:error, :sub_msat_precision_amount}
+        end
 
       {:error, error} ->
         {:error, error}

test/lightning_network/invoice_test.exs

@@ -16,9 +16,13 @@ defmodule Bitcoinex.LightningNetwork.InvoiceTest do
     test_description_coffee = "1 cup coffee"
     test_description_coffee_japanese = "ナンセンス 1杯"
 
+    test_description_blockstream_ledger =
+      "Blockstream Store: 88.85 USD for Blockstream Ledger Nano S x 1, \"Back In My Day\" Sticker x 2, \"I Got Lightning Working\" Sticker x 2 and 1 more items"
+
     # testHopHintPubkeyBytes1 = Base.decode64!("")
     testHopHintPubkey1 = "029e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255"
     testHopHintPubkey2 = "039e03a901b85534ff1e92c43c74431f7ce72046060fcf7a95c37e148f78c77255"
+    testHopHintPubkey3 = "03d06758583bb5154774a6eb221b1276c9e82d65bbaceca806d90e20c108f4b1c7"
 
     testSingleHop = [
       %HopHint{
@@ -273,6 +277,28 @@ defmodule Bitcoinex.LightningNetwork.InvoiceTest do
           min_final_cltv_expiry: 144
         }
       },
+      {
+        "lnbc9678785340p1pwmna7lpp5gc3xfm08u9qy06djf8dfflhugl6p7lgza6dsjxq454gxhj9t7a0sd8dgfkx7cmtwd68yetpd5s9xar0wfjn5gpc8qhrsdfq24f5ggrxdaezqsnvda3kkum5wfjkzmfqf3jkgem9wgsyuctwdus9xgrcyqcjcgpzgfskx6eqf9hzqnteypzxz7fzypfhg6trddjhygrcyqezcgpzfysywmm5ypxxjemgw3hxjmn8yptk7untd9hxwg3q2d6xjcmtv4ezq7pqxgsxzmnyyqcjqmt0wfjjq6t5v4khxxqyjw5qcqp2rzjq0gxwkzc8w6323m55m4jyxcjwmy7stt9hwkwe2qxmy8zpsgg7jcuwz87fcqqeuqqqyqqqqlgqqqqn3qq9qn07ytgrxxzad9hc4xt3mawjjt8znfv8xzscs7007v9gh9j569lencxa8xeujzkxs0uamak9aln6ez02uunw6rd2ht2sqe4hz8thcdagpleym0j",
+        %Invoice{
+          network: :mainnet,
+          destination: test_pubkey,
+          payment_hash: "462264ede7e14047e9b249da94fefc47f41f7d02ee9b091815a5506bc8abf75f",
+          amount_msat: 967_878_534,
+          timestamp: 1_572_468_703,
+          description: test_description_blockstream_ledger,
+          min_final_cltv_expiry: 10,
+          expiry: 604_800,
+          route_hints: [
+            %HopHint{
+              node_id: testHopHintPubkey3,
+              channel_id: 0x08FE4E000CF00001,
+              fee_base_m_sat: 1000,
+              fee_proportional_millionths: 2500,
+              cltv_expiry_delta: 40
+            }
+          ]
+        }
+      },
       {
         "lnbcrt320u1pwt8mp3pp57xs8x6cs28zedru0r0hurkz6932e86dvlrzhwvm09azv57qcekxsdqlv9k8gmeqw3jhxarfdenjqumfd4cxcegcqzpgctyyv3qkvr6khzlnd7de95hrxkw8ewfhmyzuu9dh4sgauukpk5mryaex2qs39ksupm8sxj5jsh3hw3fa0gwdjchh7ga8cx7l652g5dgqzp2ddj",
         %Invoice{
@@ -382,7 +408,21 @@ defmodule Bitcoinex.LightningNetwork.InvoiceTest do
       # mixed case
       "lnbc2500u1PvJlUeZpP5QqQsYqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsxqzpuaztrnwngzn3kdzw5hydlzf03qdgm2hdq27cqv3agm2awhz5se903vruatfhq77w3ls4evs3ch9zw97j25emudupq63nyw24cg27h2rspfj9srp",
       # Lightning Payment Request signature pubkey does not match payee pubkey
-      "lnbc1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpl2pkx2ctnv5sxxmmwwd5kgetjypeh2ursdae8g6twvus8g6rfwvs8qun0dfjkxaqnp4q0n326hr8v9zprg8gsvezcch06gfaqqhde2aj730yg0durllllll72gy6kphxuhh4a2ffwf9344ytfw98tyhvslsp9y5vt2uxdfhpucph83eqms28dyde9yxgu5ehln4zkwv04nvurxhst77vnng5s0ar9mqpm3cg0l"
+      "lnbc1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpl2pkx2ctnv5sxxmmwwd5kgetjypeh2ursdae8g6twvus8g6rfwvs8qun0dfjkxaqnp4q0n326hr8v9zprg8gsvezcch06gfaqqhde2aj730yg0durllllll72gy6kphxuhh4a2ffwf9344ytfw98tyhvslsp9y5vt2uxdfhpucph83eqms28dyde9yxgu5ehln4zkwv04nvurxhst77vnng5s0ar9mqpm3cg0l",
+      # Bech32 checksum is invalid
+      "lnbc2500u1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpquwpc4curk03c9wlrswe78q4eyqc7d8d0xqzpuyk0sg5g70me25alkluzd2x62aysf2pyy8edtjeevuv4p2d5p76r4zkmneet7uvyakky2zr4cusd45tftc9c5fh0nnqpnl2jfll544esqchsrnt",
+      # Malformed bech32 string (no 1)
+      "pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpquwpc4curk03c9wlrswe78q4eyqc7d8d0xqzpuyk0sg5g70me25alkluzd2x62aysf2pyy8edtjeevuv4p2d5p76r4zkmneet7uvyakky2zr4cusd45tftc9c5fh0nnqpnl2jfll544esqchsrny",
+      # Malformed bech32 string (mixed case)
+      "LNBC2500u1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpquwpc4curk03c9wlrswe78q4eyqc7d8d0xqzpuyk0sg5g70me25alkluzd2x62aysf2pyy8edtjeevuv4p2d5p76r4zkmneet7uvyakky2zr4cusd45tftc9c5fh0nnqpnl2jfll544esqchsrny",
+      # Signature is not recoverable.
+      "lnbc2500u1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsxqzpuaxtrnwngzn3kdzw5hydlzf03qdgm2hdq27cqv3agm2awhz5se903vruatfhq77w3ls4evs3ch9zw97j25emudupq63nyw24cg27h2rspk28uwq",
+      # String is too short.
+      "lnbc1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdpl2pkx2ctnv5sxxmmwwd5kgetjypeh2ursdae8g6na6hlh",
+      # Invalid multiplier
+      "lnbc2500x1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsxqzpujr6jxr9gq9pv6g46y7d20jfkegkg4gljz2ea2a3m9lmvvr95tq2s0kvu70u3axgelz3kyvtp2ywwt0y8hkx2869zq5dll9nelr83zzqqpgl2zg",
+      # Invalid sub-millisatoshi precision.
+      "lnbc2500000001p1pvjluezpp5qqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqqqsyqcyq5rqwzqfqypqdq5xysxxatsyp3k7enxv4jsxqzpu7hqtk93pkf7sw55rdv4k9z2vj050rxdr6za9ekfs3nlt5lr89jqpdmxsmlj9urqumg0h9wzpqecw7th56tdms40p2ny9q4ddvjsedzcplva53s"
     ]
 
     [