Use node 16.x

It required converting mocha tests code into async since [@wdio/sync is
deprecated](https://webdriver.io/docs/sync-vs-async/) starting with
node v16.
It removed the dependency on fibers and on [node-gyp + python](https://
webdriver.io/docs/sync-vs-async/#common-issues-in-sync-mode) indirectly
though which is a great thing.

Also moved away from node-sass to sass since [node-sass is deprecated]
(https://sass-lang.com/blog/libsass-is-deprecated).

test/functional/util/coverage.js

@@ -8,9 +8,9 @@ var COVERAGE_PATH = artifacts.pathSync("/coverage");
 var coverage = istanbulCov.createCoverageMap({});
 
 // Capture the coverage after each test
-afterEach(function() {
+afterEach(async function() {
   // Code coverage
-  var results = browser.execute(function() {
+  var results = await browser.execute(function() {
     return window.__coverage__;
   });
 
@@ -21,6 +21,36 @@ afterEach(function() {
 
 // Dump the coverage to a file
 after(function() {
-  var jsonStr = JSON.stringify(coverage, null, 2);
-  fs.writeFileSync(COVERAGE_PATH+"/coverage.json", jsonStr);
+
+  // Sometimes istanbul copies same location entry with null values
+  // crashing the final coverage step. This is just a workaround for now,
+  // since istanbul will be replaced by nyc.
+  const coverageJson = JSON.stringify(coverage, null, 2);
+  let newCoverage = JSON.parse(coverageJson);
+
+  Object.values(newCoverage).forEach(fileCov => {
+    if (fileCov.branchMap) {
+      Object.values(fileCov.branchMap).forEach(branchMapEntry => {
+        let prevLocation = {};
+        branchMapEntry.locations.forEach(curLocation => {
+          if (curLocation.start && curLocation.end &&
+            curLocation.start.column && curLocation.start.line &&
+            curLocation.end.column && curLocation.end.line)
+            {
+              prevLocation = curLocation;
+            }
+            else
+            {
+              curLocation.start.column = prevLocation.start.column;
+              curLocation.start.line = prevLocation.start.line;
+              curLocation.end.column = prevLocation.end.column;
+              curLocation.end.line = prevLocation.end.line;
+            }
+        })
+      })
+    }
+  })
+
+  const newCoverageJson = JSON.stringify(newCoverage, null, 2);
+  fs.writeFileSync(COVERAGE_PATH+"/coverage.json", newCoverageJson);
 })

test/functional/util/webdriverio-ext.js

@@ -1,61 +1,63 @@
 var artifacts = require("../../artifacts");
-var fs        = require("fs");
-var path      = require("path");
+var path = require("path");
 
+const extendWebdriverIO = async function() {
+  await browser.setTimeout({ 'script': 20 * 1000 });
+  await browser.setTimeout({ 'implicit': 20 * 1000 });
 
-browser.setTimeout({ 'script': 20*1000 });
-browser.setTimeout({ 'implicit': 20*1000 });
+  var SCREENSHOTS_PATH = artifacts.pathSync("/screenshots");
 
-var SCREENSHOTS_PATH = artifacts.pathSync("/screenshots");
+  /**
+   * Sometimes chrome driver can result in the wrong text.
+   *
+   * See <https://github.com/webdriverio/webdriverio/issues/1886>
+   */
+  try {
+    await browser.addCommand('setValueSafe', async function (selector, text) {
+      for (var i = 0; i < 10; i++) {
+        const elem = await $(selector);
+        await elem.waitForDisplayed(500);
 
-/**
- * Sometimes chrome driver can result in the wrong text.
- *
- * See <https://github.com/webdriverio/webdriverio/issues/1886>
- */
-try {
-  browser.addCommand('setValueSafe', function(selector, text) {
-    for(var i=0; i<10; i++) {
-      const elem = $(selector);
-      elem.waitForDisplayed(500);
+        var elements = await browser.findElements("css selector", selector);
+        if (elements.length > 1) {
+          throw "Too many elements found";
+        }
 
-      var elements = browser.findElements("css selector", selector);
-      if(elements.length > 1) {
-        throw "Too many elements found";
+        const elem2 = await $(selector);
+        await elem2.setValue(text);
+
+        var browserText = await elem2.getValue();
+
+        if (browserText == text) {
+          return;
+        }
+        else {
+          console.error("Warning: setValue failed, trying again");
+        }
       }
 
-      const elem2 = $(selector);
-      elem2.setValue(text);
-
-      var browserText = elem2.getValue();
-
-      if(browserText == text) {
-        return;
-      }
-      else {
-        console.error("Warning: setValue failed, trying again");
-      }
-    }
-
-    // Wait for change events to fire and state updated
-    browser.flushReactUpdates();
-  })
-
-  browser.addCommand('takeScreenShot', function(filepath) {
-    var savepath = path.join(SCREENSHOTS_PATH, filepath);
-    browser.saveScreenshot(savepath);
-  });
-
-  browser.addCommand('flushReactUpdates', function() {
-    browser.executeAsync(function(done) {
-      // For any events to propogate
-      setTimeout(function() {
-        // For the DOM to be updated.
-        setTimeout(done, 0);
-      }, 0)
+      // Wait for change events to fire and state updated
+      await browser.flushReactUpdates();
     })
-  })
 
-} catch(err) {
-  console.error(">>> Ignored error: "+err);
+    await browser.addCommand('takeScreenShot', async function (filepath) {
+      var savepath = path.join(SCREENSHOTS_PATH, filepath);
+      await browser.saveScreenshot(savepath);
+    });
+
+    await browser.addCommand('flushReactUpdates', async function () {
+      await browser.executeAsync(function (done) {
+        // For any events to propagate
+        setTimeout(function () {
+          // For the DOM to be updated.
+          setTimeout(done, 0);
+        }, 0)
+      })
+    })
+
+  } catch (err) {
+    console.error(">>> Ignored error: " + err);
+  }
 }
+
+module.exports = extendWebdriverIO;