Improve formatting for BTC amounts

package-lock.json

@@ -1387,6 +1387,14 @@
         }
       }
     },
+    "fmtbtc": {
+      "version": "0.0.3",
+      "resolved": "https://registry.npmjs.org/fmtbtc/-/fmtbtc-0.0.3.tgz",
+      "integrity": "sha512-3awolswh6476ce5gIvzjw6OgT7ae2WD5NSinOC/de8gLeaDQPdYlW94Hb6nCoTXMUP6AFe3eh3IQiuT+dp4c8A==",
+      "requires": {
+        "move-decimal-point": "0.0.4"
+      }
+    },
     "for-in": {
       "version": "1.0.2",
       "resolved": "https://registry.npmjs.org/for-in/-/for-in-1.0.2.tgz",

package.json

@@ -26,6 +26,7 @@
     "express": "^4.16.3",
     "file-extension": "^4.0.2",
     "file-type": "^7.6.0",
+    "fmtbtc": "0.0.3",
     "fs-extra": "^5.0.0",
     "gm": "^1.23.1",
     "js-yaml": "^3.11.0",
@@ -35,7 +36,6 @@
     "markdown-it": "^8.4.1",
     "mime-types": "^2.1.18",
     "morgan": "^1.9.0",
-    "move-decimal-point": "0.0.4",
     "pretty-bytes": "^4.0.2",
     "pug": "^2.0.3",
     "qruri": "0.0.3",

src/app.js

@@ -1,6 +1,7 @@
 import fs from 'fs'
 import path from 'path'
-import { pwrap, pick, fcurrency, fmsat, pngPixel } from './lib/util'
+import { msat2milli } from 'fmtbtc'
+import { pwrap, pick, fcurrency, pngPixel } from './lib/util'
 
 // Setup
 const app     = require('express')()
@@ -23,7 +24,7 @@ app.enable('case sensitive routing')
 
 // View locals
 Object.assign(app.locals, {
-  conf, fmsat, fcurrency
+  conf, msat2milli, fcurrency
 , prettybytes: require('pretty-bytes')
 , markdown:    require('markdown-it')()
 , qruri:       require('qruri')

src/lib/config.js

@@ -41,7 +41,7 @@ module.exports = basePath => {
 const parsePrice = str => {
   const m = str.match(/^([\d.]+) ([a-z]+)$/i)
   if (!m) throw new Error(`invalid price: ${ str }`)
-  return { amount: m[1], currency: m[2] }
+  return { amount: m[1], currency: m[2].toUpperCase() }
 }
 
 const parseFiles = (files, prefix='') =>

src/lib/util.js

@@ -1,6 +1,6 @@
-import { execFile } from 'child_process'
-import moveDec      from 'move-decimal-point'
-import CurrencyF    from 'currency-formatter'
+import { execFile }  from 'child_process'
+import { btc2milli } from 'fmtbtc'
+import CurrencyF     from 'currency-formatter'
 
 // Promise wrapper for express handler functions
 const pwrap = fn => (req, res, next, ...a) =>
@@ -14,13 +14,12 @@ const exec = (cmd, ...args) => new Promise((resolve, reject) =>
 // Pick specified object properties
 const pick = (O, ...K) => K.reduce((o, k) => (o[k]=O[k], o), {})
 
-// Format milli-satoshis as milli-bitcoins
-const fmsat = msat => moveDec(msat, -8)
-
 // Format price with currency symbol
-const fcurrency = p => CurrencyF.format(p.amount, { code: p.currency.toUpperCase() })
+//
+const fcurrency = p => p.currency === 'BTC' ? `${btc2milli(p.amount, true)} mBTC`
+                       : CurrencyF.format(p.amount, { code: p.currency })
 
 // Empty 1x1 PNG pixel
 const pngPixel = Buffer.from('iVBORw0KGgoAAAANSUhEUgAAAAEAAAABCAQAAAC1HAwCAAAAC0lEQVR42mNkYAAAAAYAAjCB0C8AAAAASUVORK5CYII=', 'base64')
 
-module.exports = { pwrap, exec, pick, fmsat, fcurrency, pngPixel }
+module.exports = { pwrap, exec, pick, fcurrency, pngPixel }

views/_checkout.pug

@@ -7,7 +7,10 @@ if invoice.status == 'expired'
 else
   .checkout
     h3 Pay with Lightning
-    h4 #[strong= invoice.quoted_amount] #{invoice.quoted_currency } = #[strong= fmsat(invoice.msatoshi)] mBTC
+    if invoice.quoted_currency && invoice.quoted_currency != 'BTC'
+      h4 #[strong= invoice.quoted_amount] #{invoice.quoted_currency} ≈ #[strong= msat2milli(invoice.msatoshi)] mBTC
+    else
+      h4 #[strong= msat2milli(invoice.msatoshi)] mBTC
     .row
       .pay.col-sm-8
         pre= invoice.payreq