Support float zooms in bounds() function (#19)

* Strips trailing whitespace from package.json

This formatting change was generated automatically when running
`npm install` with npm v6.1.0.

* Upgrades node-sphericalmercator to v1.1.0

This version now supports float-based zoom levels.

* Adds test for float zoom input for bounds function

* Refactors expected test values to be more explicit

* Rebuilds dist version of geo-viewport.js with latest sphericalmercator

package.json

@@ -1,34 +1,34 @@
 {
-  "license": "BSD-2-Clause", 
-  "name": "@mapbox/geo-viewport", 
+  "license": "BSD-2-Clause",
+  "name": "@mapbox/geo-viewport",
   "repository": {
-    "url": "git@github.com:mapbox/geo-viewport.git", 
+    "url": "git@github.com:mapbox/geo-viewport.git",
     "type": "git"
-  }, 
-  "author": "Tom MacWright", 
+  },
+  "author": "Tom MacWright",
   "bugs": {
     "url": "https://github.com/mapbox/geo-viewport/issues"
-  }, 
-  "version": "0.2.2", 
+  },
+  "version": "0.2.2",
   "dependencies": {
-    "@mapbox/sphericalmercator": "~1.0.2"
-  }, 
+    "@mapbox/sphericalmercator": "~1.1.0"
+  },
   "scripts": {
-    "test": "tap test/*.js", 
+    "test": "tap test/*.js",
     "build": "browserify -s geoViewport index.js | uglifyjs -c > geo-viewport.js"
-  }, 
+  },
   "keywords": [
-    "geographic", 
-    "viewport", 
-    "zoom", 
+    "geographic",
+    "viewport",
+    "zoom",
     "scale"
-  ], 
+  ],
   "devDependencies": {
-    "browserify": "^13.0.0", 
-    "uglify-js": "^2.6.2", 
+    "browserify": "^13.0.0",
+    "uglify-js": "^2.6.2",
     "tap": "^5.7.0"
-  }, 
-  "main": "index.js", 
-  "homepage": "https://github.com/mapbox/geo-viewport", 
+  },
+  "main": "index.js",
+  "homepage": "https://github.com/mapbox/geo-viewport",
   "description": "convert between viewports and extents"
 }

test/viewport.js

@@ -60,9 +60,24 @@ test('bounds for 512px tiles', function (t) {
     var xMax = bounds[2];
     var yMax = bounds[3];
 
-    t.equal(precisionRound(xMin, decDegreesFloatTolerance), precisionRound(-77.03945338726044, decDegreesFloatTolerance));
-    t.equal(precisionRound(yMin, decDegreesFloatTolerance), precisionRound(38.89697827424865, decDegreesFloatTolerance));
-    t.equal(precisionRound(xMax, decDegreesFloatTolerance), precisionRound(-77.03365981578827, decDegreesFloatTolerance));
-    t.equal(precisionRound(yMax, decDegreesFloatTolerance), precisionRound(38.89843950894583, decDegreesFloatTolerance));
+    t.equal(precisionRound(xMin, decDegreesFloatTolerance), -77.03945339);
+    t.equal(precisionRound(yMin, decDegreesFloatTolerance), 38.89697827);
+    t.equal(precisionRound(xMax, decDegreesFloatTolerance), -77.03365982);
+    t.equal(precisionRound(yMax, decDegreesFloatTolerance), 38.89843951);
     t.end();
 });
+
+test('bounds for float zooms', function (t) {
+  var zoom = 16.52;
+  var bounds = viewport.bounds([-77.036556, 38.897708], zoom, [1080, 350], 512);
+  var xMin = bounds[0];
+  var yMin = bounds[1];
+  var xMax = bounds[2];
+  var yMax = bounds[3];
+
+  t.equal(precisionRound(xMin, decDegreesFloatTolerance), -77.04059627);
+  t.equal(precisionRound(yMin, decDegreesFloatTolerance), 38.89668897);
+  t.equal(precisionRound(xMax, decDegreesFloatTolerance), -77.03251573);
+  t.equal(precisionRound(yMax, decDegreesFloatTolerance), 38.89872702);
+  t.end();
+});