Load base64 encoded code (#856)

fix https://github.com/ethereum/remix-project/issues/852

apps/remix-ide-e2e/src/tests/url.test.ts

@@ -11,13 +11,22 @@ const sources = [
 
 module.exports = {
   before: function (browser: NightwatchBrowser, done: VoidFunction) {
-    init(browser, done, 'http://127.0.0.1:8080/#optimize=true&runs=300&evmVersion=istanbul&version=soljson-v0.7.4+commit.3f05b770.js')
+    init(browser, done, 'http://127.0.0.1:8080/#optimize=true&runs=300&evmVersion=istanbul&version=soljson-v0.7.4+commit.3f05b770.js&code=cHJhZ21hIHNvbGlkaXR5ID49MC42LjAgPDAuNy4wOwoKaW1wb3J0ICJodHRwczovL2dpdGh1Yi5jb20vT3BlblplcHBlbGluL29wZW56ZXBwZWxpbi1jb250cmFjdHMvYmxvYi9tYXN0ZXIvY29udHJhY3RzL2FjY2Vzcy9Pd25hYmxlLnNvbCI7Cgpjb250cmFjdCBHZXRQYWlkIGlzIE93bmFibGUgewogIGZ1bmN0aW9uIHdpdGhkcmF3KCkgZXh0ZXJuYWwgb25seU93bmVyIHsKICB9Cn0')
   },
   
   '@sources': function () {
     return sources
   },
 
+  'Should load the code from URL params': function (browser: NightwatchBrowser) {
+    browser
+      .getEditorValue((content) => {
+        browser.assert.ok(content.indexOf(
+          'https://github.com/OpenZeppelin/openzeppelin-contracts/blob/master/contracts/access/Ownable.sol') != -1, 
+          'code has not been loaded')
+      })
+  },
+
   'Should load using URL compiler params': function (browser: NightwatchBrowser) {
     browser
     .assert.containsText('#versionSelector option[selected="selected"]', '0.7.4+commit.3f05b770')

apps/remix-ide/src/app.js

@@ -459,5 +459,14 @@ Please make a backup of your contracts and start using http://remix.ethereum.org
     })
   }
 
+  if (params.code) {
+    try {
+      const path = 'browser/.code-sample/contract.sol'
+      await fileManager.writeFile(path, atob(params.code))
+      await fileManager.openFile(path)
+    } catch (e) {
+      console.error(e)
+    }
+  }
   if (params.embed) framingService.embed()
 }