Remove dependency on removed nyc feature

Author: albertyw

lib/chromium.js

@@ -126,19 +126,19 @@ module.exports = function (b, opts) {
           return;
         }
         if (text.indexOf('[COVERAGE ') === 0) {
-          if (process.env.NYC_ROOT_ID) {
-            var nycConfig = JSON.parse(process.env.NYC_CONFIG);
-            var json = text.substring(10, text.length - 1);
-            var file = path.join(nycConfig.tempDir,
-              process.env.NYC_ROOT_ID + '.json');
-            fs.writeFile(file, json, 'utf8', function (err) {
-              if (err) {
-                b.emit('error', err);
-              }
-            });
-            return;
+          var nycRootID = process.env.NYC_ROOT_ID;
+          if (!nycRootID) {
+            // NYC >v15 does not export a NYC_ROOT_ID so use a "random" uuid instead
+            nycRootID = '4638ceac-c8d9-411d-9e1f-72755846a221';
           }
-          output.write('Coverage information received, but no nyc\n');
+          var nycConfig = JSON.parse(process.env.NYC_CONFIG);
+          var json = text.substring(10, text.length - 1);
+          var file = path.join(nycConfig.tempDir, nycRootID + '.json');
+          fs.writeFile(file, json, 'utf8', function (err) {
+            if (err) {
+              b.emit('error', err);
+            }
+          });
           return;
         }
         if (text.indexOf('[EXIT ') === 0) {