Theme persist verilog editor (CircuitVerse#3006)

* feature: verilog-themes CircuitVerse#2829

* feature: apply theme change on selecting from dropdown CircuitVerse#2829

* removed some themes for verilog editor

* restoring previous theme of code editor on reload or revisit

* fix: some possible code climate issues

* fixed code-climate issue convert let to const

Author: devartstar

app/views/simulator/edit.html.erb

@@ -306,15 +306,15 @@
         <p class="text-center mb-2">Select a theme: </p>
           <select id="selectVerilogTheme" class="applyTheme" style="width:90%;">    
             <optgroup label="Light Themes">     
-              <option value="1">default</option>
-              <option value="2">solarized</option>
-              <option value="3">elegant</option>
-              <option value="4">neat</option>
-              <option value="5">idea</option>
-              <option value="6">neo</option>
+              <option>default</option>
+              <option>solarized</option>
+              <option>elegant</option>
+              <option>neat</option>
+              <option>idea</option>
+              <option>neo</option>
             </optgroup>
             <optgroup label="Dark Themes">
-              <option value="7">blackboard</option>
+              <option>blackboard</option>
               <option>cobalt</option>
               <option>night</option>
               <option>the-matrix</option>

simulator/src/Verilog2CV.js

@@ -45,6 +45,7 @@ export function saveVerilogCode() {
 export function applyVerilogTheme() {
     var dropdown = document.getElementById('selectVerilogTheme');
     var theme = dropdown.options[dropdown.selectedIndex].innerHTML;
+    localStorage.setItem('verilog-theme', theme);
     editor.setOption('theme', theme);
 }
 
@@ -216,6 +217,13 @@ export function setupCodeMirrorEnvironment() {
         extraKeys: {"Ctrl-Space": "autocomplete"}
     });
 
+    if (!localStorage.getItem('verilog-theme')) {
+        localStorage.setItem('verilog-theme', 'default');
+    } else {
+        const prevtheme = localStorage.getItem('verilog-theme');
+        editor.setOption('theme', prevtheme);
+    }
+
     editor.setValue("// Write Some Verilog Code Here!")
     setTimeout(function() {
         editor.refresh();