Updated var declarations to const/let and no lists

- All var declarations are now const or let as per ES6
- All comma-separated lists / chained declarations are now one declaration per line
- This is for clarity/readability but also made running the var-to-const/let switch smoother
- ESLint rules updated to match

How this was done:

- npm install -g jscodeshift
- git clone https://github.com/cpojer/js-codemod.git
- git clone git@github.com:TryGhost/Ghost.git shallow-ghost
- cd shallow-ghost
- jscodeshift -t ../js-codemod/transforms/unchain-variables.js . -v=2
- jscodeshift -t ../js-codemod/transforms/no-vars.js . -v=2
- yarn
- yarn test
- yarn lint / fix various lint errors (almost all indent) by opening files and saving in vscode
- grunt test-regression
- sorted!

ghost/promise/lib/pipeline.js

@@ -4,21 +4,21 @@
  * Based on pipeline.js from when.js:
  * https://github.com/cujojs/when/blob/3.7.4/pipeline.js
  */
-var Promise = require('bluebird');
+const Promise = require('bluebird');
 
 function pipeline(tasks /* initial arguments */) {
-    var args = Array.prototype.slice.call(arguments, 1),
+    const args = Array.prototype.slice.call(arguments, 1);
 
-        runTask = function (task, args) {
-            // Self-optimizing function to run first task with multiple
-            // args using apply, but subsequent tasks via direct invocation
-            runTask = function (task, arg) {
-                return task(arg);
-            };
-
-            return task.apply(null, args);
+    let runTask = function (task, args) {
+        // Self-optimizing function to run first task with multiple
+        // args using apply, but subsequent tasks via direct invocation
+        runTask = function (task, arg) {
+            return task(arg);
         };
 
+        return task.apply(null, args);
+    };
+
     // Resolve any promises for the arguments passed in first
     return Promise.all(args).then(function (args) {
         // Iterate through the tasks passing args from one into the next

ghost/promise/test/pipeline_spec.js

@@ -1,9 +1,9 @@
-var should = require('should'),
-    sinon = require('sinon'),
-    Promise = require('bluebird'),
+const should = require('should');
+const sinon = require('sinon');
+const Promise = require('bluebird');
 
-    // Stuff we are testing
-    pipeline = require('../../../../core/server/lib/promise/pipeline');
+// Stuff we are testing
+const pipeline = require('../../../../core/server/lib/promise/pipeline');
 
 // These tests are based on the tests in https://github.com/cujojs/when/blob/3.7.4/test/pipeline-test.js
 function createTask(y) {
@@ -36,8 +36,8 @@ describe('Pipeline', function () {
     });
 
     it('should pass args to initial task', function () {
-        var expected = [1, 2, 3],
-            tasks = [sinon.spy()];
+        const expected = [1, 2, 3];
+        const tasks = [sinon.spy()];
 
         return pipeline(tasks, 1, 2, 3).then(function () {
             tasks[0].calledOnce.should.be.true();
@@ -46,9 +46,9 @@ describe('Pipeline', function () {
     });
 
     it('should allow initial args to be promises', function () {
-        var expected = [1, 2, 3],
-            tasks = [sinon.spy()],
-            Resolver = Promise.resolve;
+        const expected = [1, 2, 3];
+        const tasks = [sinon.spy()];
+        const Resolver = Promise.resolve;
 
         return pipeline(tasks, new Resolver(1), new Resolver(2), new Resolver(3)).then(function () {
             tasks[0].calledOnce.should.be.true();
@@ -57,12 +57,13 @@ describe('Pipeline', function () {
     });
 
     it('should allow tasks to be promises', function () {
-        var expected = [1, 2, 3],
-            tasks = [
-                sinon.stub().returns(new Promise.resolve(4)),
-                sinon.stub().returns(new Promise.resolve(5)),
-                sinon.stub().returns(new Promise.resolve(6))
-            ];
+        const expected = [1, 2, 3];
+
+        const tasks = [
+            sinon.stub().returns(new Promise.resolve(4)),
+            sinon.stub().returns(new Promise.resolve(5)),
+            sinon.stub().returns(new Promise.resolve(6))
+        ];
 
         return pipeline(tasks, 1, 2, 3).then(function (result) {
             result.should.eql(6);
@@ -76,13 +77,15 @@ describe('Pipeline', function () {
     });
 
     it('should allow tasks and args to be promises', function () {
-        var expected = [1, 2, 3],
-            tasks = [
-                sinon.stub().returns(new Promise.resolve(4)),
-                sinon.stub().returns(new Promise.resolve(5)),
-                sinon.stub().returns(new Promise.resolve(6))
-            ],
-            Resolver = Promise.resolve;
+        const expected = [1, 2, 3];
+
+        const tasks = [
+            sinon.stub().returns(new Promise.resolve(4)),
+            sinon.stub().returns(new Promise.resolve(5)),
+            sinon.stub().returns(new Promise.resolve(6))
+        ];
+
+        const Resolver = Promise.resolve;
 
         return pipeline(tasks, new Resolver(1), new Resolver(2), new Resolver(3)).then(function (result) {
             result.should.eql(6);