add update version task:

- update src/index.js and src/assets/geo_assets.js 'version' export
  using a falafel update
- done replacement of require('../package.json') so that webpack
  is supported w/o a json loader

Author: etpinard

tasks/preprocess.js

@@ -4,6 +4,7 @@ var sass = require('node-sass');
 
 var pullCSS = require('./util/pull_css');
 var pullFontSVG = require('./util/pull_font_svg');
+var updateVersion = require('./util/update_version');
 var constants = require('./util/constants');
 
 
@@ -28,3 +29,7 @@ fs.copy(constants.pathToTopojsonSrc, constants.pathToTopojsonDist,
     { clobber: true },
     function(err) { if(err) throw err; }
 );
+
+// inject package version into source index files
+updateVersion(constants.pathToPlotlySrc);
+updateVersion(constants.pathToPlotlyGeoAssetsSrc);

tasks/util/update_version.js

@@ -0,0 +1,30 @@
+var fs = require('fs');
+
+var falafel = require('falafel');
+
+var pkg = require('../../package.json');
+
+
+module.exports = function updateVersion(pathToFile) {
+    fs.readFile(pathToFile, 'utf-8', function(err, code) {
+        var out = falafel(code, function(node) {
+            if(isVersionNode(node)) node.update('\'' + pkg.version + '\'');
+        });
+
+        fs.writeFile(pathToFile, out, function(err) {
+            if(err) throw err;
+        });
+    });
+};
+
+function isVersionNode(node) {
+    return (
+        node.type === 'Literal' &&
+        node.parent &&
+        node.parent.type === 'AssignmentExpression' &&
+        node.parent.left &&
+        node.parent.left.object &&
+        node.parent.left.property &&
+        node.parent.left.property.name === 'version'
+    );
+}