Update diff for v8

- remove setConstant
- add setCenter
- add setZoom
- add setBearing
- add setPitch

Issue: #338

lib/diff.js

@@ -50,52 +50,47 @@ var operations = {
     setLayerZoomRange: 'setLayerZoomRange',
 
     /*
-     * { command: 'setConstant', args: ['constantName', value] }
+     * { command: 'setLayerProperty', args: ['layerId', 'prop', value] }
      */
-    setConstant: 'setConstant',
+    setLayerProperty: 'setLayerProperty',
 
     /*
-     * { command: 'setSprite', args: ['spriteUrl'] }
+     * { command: 'setCenter', args: [[lon, lat]] }
      */
-    setSprite: 'setSprite',
+    setCenter: 'setCenter',
 
     /*
-     * { command: 'setGlyphs', args: ['glyphsUrl'] }
+     * { command: 'setZoom', args: [zoom] }
      */
-    setGlyphs: 'setGlyphs',
+    setZoom: 'setZoom',
 
     /*
-     * { command: 'setTransition', args: [transition] }
+     * { command: 'setBearing', args: [bearing] }
      */
-    setTransition: 'setTransition',
+    setBearing: 'setBearing',
 
     /*
-     * { command: 'setLayerProperty', args: ['layerId', 'prop', value] }
+     * { command: 'setPitch', args: [pitch] }
      */
-    setLayerProperty: 'setLayerProperty'
+    setPitch: 'setPitch',
 
-};
+    /*
+     * { command: 'setSprite', args: ['spriteUrl'] }
+     */
+    setSprite: 'setSprite',
 
+    /*
+     * { command: 'setGlyphs', args: ['glyphsUrl'] }
+     */
+    setGlyphs: 'setGlyphs',
 
-function diffConstants(before, after, commands) {
-    before = before || {};
-    after = after || {};
+    /*
+     * { command: 'setTransition', args: [transition] }
+     */
+    setTransition: 'setTransition'
 
-    var prop;
+};
 
-    for (prop in before) {
-        if (!before.hasOwnProperty(prop)) continue;
-        if (!isEqual(before[prop], after[prop])) {
-            commands.push({ command: operations.setConstant, args: [prop, after[prop]] });
-        }
-    }
-    for (prop in after) {
-        if (!after.hasOwnProperty(prop) || before.hasOwnProperty(prop)) continue;
-        if (!isEqual(before[prop], after[prop])) {
-            commands.push({ command: operations.setConstant, args: [prop, after[prop]] });
-        }
-    }
-}
 
 function diffSources(before, after, commands) {
     before = before || {};
@@ -276,6 +271,18 @@ function diffStyles(before, after) {
         if (!isEqual(before.version, after.version)) {
             return [{ command: operations.setStyle, args: [after] }];
         }
+        if (!isEqual(before.center, after.center)) {
+            commands.push({ command: operations.setCenter, args: [after.center] });
+        }
+        if (!isEqual(before.zoom, after.zoom)) {
+            commands.push({ command: operations.setZoom, args: [after.zoom] });
+        }
+        if (!isEqual(before.bearing, after.bearing)) {
+            commands.push({ command: operations.setBearing, args: [after.bearing] });
+        }
+        if (!isEqual(before.pitch, after.pitch)) {
+            commands.push({ command: operations.setPitch, args: [after.pitch] });
+        }
         if (!isEqual(before.sprite, after.sprite)) {
             commands.push({ command: operations.setSprite, args: [after.sprite] });
         }
@@ -285,7 +292,6 @@ function diffStyles(before, after) {
         if (!isEqual(before.transition, after.transition)) {
             commands.push({ command: operations.setTransition, args: [after.transition] });
         }
-        diffConstants(before.constants, after.constants, commands);
         diffSources(before.sources, after.sources, commands);
         diffLayers(before.layers, after.layers, commands);
     } catch (e) {

test/diff.js

@@ -6,31 +6,22 @@ var t = require('tape'),
 t('diff', function (t) {
 
     t.deepEqual(diffStyles({
-        constants: { '@a': 1 }
+        layers: [{ id: 'a' }]
     }, {
-        constants: { '@a': 1 }
+        layers: [{ id: 'a' }]
     }), [], 'no changes');
 
     t.deepEqual(diffStyles({
-        version: 6,
-        constants: { '@a': 1 }
-    }, {
         version: 7,
-        constants: { '@a': 1 }
+        layers: [{ id: 'a' }]
+    }, {
+        version: 8,
+        layers: [{ id: 'a' }]
     }), [
-      { command: 'setStyle', args: [{ version: 7, constants: { '@a': 1 } }] }
+      { command: 'setStyle', args: [{ version: 8, layers: [{ id: 'a' }] }] }
     ], 'version change');
 
 
-    t.deepEqual(diffStyles({
-        constants: { '@a': 1 }
-    }, {
-        constants: { '@b': 1 }
-    }), [
-      { command: 'setConstant', args: ['@a', undefined] },
-      { command: 'setConstant', args: ['@b', 1] }
-    ], 'set constants');
-
     t.deepEqual(diffStyles({
         layers: [{ id: 'a' }]
     }, {
@@ -130,5 +121,37 @@ t('diff', function (t) {
         layers: [{ id: 'a', metadata: { 'mapbox:group': 'Another Name' } }]
     }), [], 'ignore layer metadata');
 
+    t.deepEqual(diffStyles({
+        center: [0, 0]
+    }, {
+        center: [1, 1]
+    }), [
+      { command: 'setCenter', args: [[1, 1]] }
+    ], 'center change');
+
+    t.deepEqual(diffStyles({
+        zoom: 12
+    }, {
+        zoom: 15
+    }), [
+      { command: 'setZoom', args: [15] }
+    ], 'zoom change');
+
+    t.deepEqual(diffStyles({
+        bearing: 0
+    }, {
+        bearing: 180
+    }), [
+      { command: 'setBearing', args: [180] }
+    ], 'bearing change');
+
+    t.deepEqual(diffStyles({
+        pitch: 0
+    }, {
+        pitch: 1
+    }), [
+      { command: 'setPitch', args: [1] }
+    ], 'pitch change');
+
     t.end();
 });