From ecb7c20bbff5148671c42d972b0ff7b0aa1e2797 Mon Sep 17 00:00:00 2001
From: =?UTF-8?q?Minh=20Nguy=E1=BB=85n?= <mxn@1ec5.org>
Date: Tue, 16 Nov 2021 17:04:29 -0800
Subject: [PATCH] Avoid truncation when formatting numbers

---
 modules/core/localizer.js   | 4 ++--
 test/spec/core/localizer.js | 4 ++++
 2 files changed, 6 insertions(+), 2 deletions(-)

diff --git a/modules/core/localizer.js b/modules/core/localizer.js
index 2e100a4eb..e87bfde21 100644
--- a/modules/core/localizer.js
+++ b/modules/core/localizer.js
@@ -429,7 +429,7 @@ export function coreLocalizer() {
               'formatToParts' in Intl.NumberFormat.prototype)) {
             return (number) => number.toString();
         } else {
-            return (number) => number.toLocaleString(locale);
+            return (number) => number.toLocaleString(locale, { maximumFractionDigits: 20 });
         }
     };
 
@@ -437,7 +437,7 @@ export function coreLocalizer() {
         // https://stackoverflow.com/a/55366435/4585461
         const polyfill = (string) => parseFloat(string.trim());
         if (!('Intl' in window && 'NumberFormat' in Intl)) return polyfill;
-        const format = new Intl.NumberFormat(locale);
+        const format = new Intl.NumberFormat(locale, { maximumFractionDigits: 20 });
         if (!('formatToParts' in format)) return polyfill;
         const parts = format.formatToParts(12345.6);
         const numerals = Array.from({ length: 10 }).map((_, i) => format.format(i));
diff --git a/test/spec/core/localizer.js b/test/spec/core/localizer.js
index 0dbe82c71..8f773663f 100644
--- a/test/spec/core/localizer.js
+++ b/test/spec/core/localizer.js
@@ -15,6 +15,7 @@ describe('iD.coreLocalizer', function() {
             expect(parseFloat(formatFloat(1.234))).to.eql(1.234);
             expect(parseFloat(formatFloat(1234))).to.eql(1234);
             expect(parseFloat(formatFloat(1234.56))).to.eql(1234.56);
+            expect(parseFloat(formatFloat(3.14159))).to.eql(3.14159);
         });
         it('roundtrips Spanish numbers', function () {
             var localizer = iD.coreLocalizer();
@@ -24,6 +25,7 @@ describe('iD.coreLocalizer', function() {
             expect(parseFloat(formatFloat(1.234))).to.eql(1.234);
             expect(parseFloat(formatFloat(1234))).to.eql(1234);
             expect(parseFloat(formatFloat(1234.56))).to.eql(1234.56);
+            expect(parseFloat(formatFloat(3.14159))).to.eql(3.14159);
         });
         it('roundtrips Arabic numbers', function () {
             var localizer = iD.coreLocalizer();
@@ -33,6 +35,7 @@ describe('iD.coreLocalizer', function() {
             expect(parseFloat(formatFloat(1.234))).to.eql(1.234);
             expect(parseFloat(formatFloat(1234))).to.eql(1234);
             expect(parseFloat(formatFloat(1234.56))).to.eql(1234.56);
+            expect(parseFloat(formatFloat(3.14159))).to.eql(3.14159);
         });
         it('roundtrips Bengali numbers', function () {
             var localizer = iD.coreLocalizer();
@@ -42,6 +45,7 @@ describe('iD.coreLocalizer', function() {
             expect(parseFloat(formatFloat(1.234))).to.eql(1.234);
             expect(parseFloat(formatFloat(1234))).to.eql(1234);
             expect(parseFloat(formatFloat(1234.56))).to.eql(1234.56);
+            expect(parseFloat(formatFloat(3.14159))).to.eql(3.14159);
         });
     });
 });