switch to expr-eval for dynamic module (#1729)

* switch to expr-eval for dynamic module

* added expr-eval module

* Update Module.js

* update options test to correctly label varied options

* Update options-test.js

* make expressions/options case insensitive

* Update Module.js

Co-authored-by: Harsh Khandeparkar <34770591+HarshKhandeparkar@users.noreply.github.com>

package.json

@@ -46,6 +46,7 @@
     "data-uri-to-buffer": "^3.0.0",
     "downloadjs": "^1.4.7",
     "eslint": "^6.1.0",
+    "expr-eval": "^2.0.2",
     "fisheyegl": "^0.1.2",
     "font-awesome": "~4.7.0",
     "geotiff": "^1.0.0-beta.6",

src/modules/Dynamic/Module.js

@@ -14,20 +14,18 @@ module.exports = function Dynamic(options, UI) {
     options.blue = options.blue || defaults.blue;
     options.green = options.green || defaults.green;
 
+    const Parser = require('expr-eval').Parser;
     function generator(expression) {
-      var func = 'f = function (r, g, b, a) { var R = r, G = g, B = b, A = a; return ' + expression + ';}';
-      var f;
-      eval(func);
-      return f;
+      let expr = Parser.parse('R = r; G = g; B = b; A = a; ' + expression);
+      return expr.toJSFunction("r,g,b,a,R,G,B,A");
     }
-
+    
     var channels = ['red', 'green', 'blue', 'alpha'];
 
     channels.forEach(function(channel) {
       if (channel === 'alpha'){
         options['alpha_function'] = function() { return 255; };
-      }
-      else{
+      } else {
         options[channel + '_function'] = generator(options[channel]);
       }
     });

test/core/templates/options-test.js

@@ -37,7 +37,7 @@ module.exports = (moduleName, options, benchmark, input) => {
       looksSame(result, benchmark[0], function(err, res) {
         if (err) console.log(err);
 
-        t.equal(res.equal, true, `${moduleName} module works correctly with initial option ${options[0][moduleName]}`);
+        t.equal(res.equal, true, `${moduleName} module works correctly with initial option ${JSON.stringify(options[0])}`);
       });
       // Change the option of the given module.
       sequencer.steps[1].setOptions(options[1]);
@@ -54,7 +54,7 @@ module.exports = (moduleName, options, benchmark, input) => {
         looksSame(newResult, benchmark[1], function(err, res) {
           if (err) console.log(err);
 
-          t.equal(res.equal, true, `${moduleName} module works correctly when the option is changed to ${options[1][moduleName]}`);
+          t.equal(res.equal, true, `${moduleName} module works correctly when the option is changed to ${JSON.stringify(options[1])}`);
           sequencer = null;
           t.end();
         });