From 2cfa109283dbebdba41ac333a49641abfbf8d959 Mon Sep 17 00:00:00 2001
From: Tim Otten <totten@civicrm.org>
Date: Thu, 16 Apr 2015 15:19:56 -0700
Subject: [PATCH] Add CRM.sigfig utility

---
 js/Common.js                   |  7 +++++++
 tests/karma/unit/sigfigSpec.js | 14 ++++++++++++++
 2 files changed, 21 insertions(+)
 create mode 100644 tests/karma/unit/sigfigSpec.js

diff --git a/js/Common.js b/js/Common.js
index 4950046ee0..c77d649635 100644
--- a/js/Common.js
+++ b/js/Common.js
@@ -1378,4 +1378,11 @@ CRM.strings = CRM.strings || {};
   CRM.checkPerm = function(perm) {
     return CRM.permissions[perm];
   };
+
+  // Round while preserving sigfigs
+  CRM.sigfig = function(n, digits) {
+    var len = ("" + n).length;
+    var scale = Math.pow(10.0, len-digits);
+    return Math.round(n / scale) * scale;
+  };
 })(jQuery, _);
diff --git a/tests/karma/unit/sigfigSpec.js b/tests/karma/unit/sigfigSpec.js
new file mode 100644
index 0000000000..9b593b3d63
--- /dev/null
+++ b/tests/karma/unit/sigfigSpec.js
@@ -0,0 +1,14 @@
+'use strict';
+
+describe('CRM.sigfig', function() {
+  it('should round while preserving significant digits', function(){
+    expect(CRM.sigfig(9, 1)).toBe(9);
+    expect(CRM.sigfig(172, 1)).toBe(200);
+    expect(CRM.sigfig(172, 2)).toBe(170);
+    expect(CRM.sigfig(176, 2)).toBe(180);
+    expect(CRM.sigfig(1492, 1)).toBe(1000);
+    expect(CRM.sigfig(1492, 2)).toBe(1500);
+    expect(CRM.sigfig(1492, 3)).toBe(1490);
+    expect(CRM.sigfig(10943, 3)).toBe(10900);
+  });
+});
-- 
2.25.1