Wednesday, 23 September 2015

Definitely Typed Shouldn't Exist

OK - the title's total clickbait but stay with me; there's a point here.

I'm a member of the Definitely Typed team - and hopefully I won't be kicked out for writing this. My point is this: .d.ts files should live with the package they provide typing information for, in npm / GitHub etc. Not separately. TypeScript 1.6 has just been released. Yay! In the release blog post it says this:

We’ve changed module resolution when doing CommonJS output to work more closely to how Node does module resolution. If a module name is non-relative, we now follow these steps to find the associated typings:

  1. Check in node_modules for <module name>.d.ts
  2. Search node_modules\<module name>\package.json for a typings field
  3. Look for node_modules\<module name>\index.d.ts
  4. Then we go one level higher and repeat the process

Please note: when we search through node_modules, we assume these are the packaged node modules which have type information and a corresponding .js file. As such, we resolve only .d.ts files (not .ts file) for non-relative names.

Previously, we treated all module names as relative paths, and therefore we would never properly look in node_modules... We will continue to improve module resolution, including improvements to AMD, in upcoming releases.

The TL;DR is this: consuming npm packages which come with definition files should JUST WORK™... npm is now a first class citizen in TypeScriptLand. So everyone who has a package on npm should now feel duty bound to include a .d.ts when they publish and Definitely Typed can shut up shop. Simple right?

Wrong!

Yeah, it's never going to happen. Surprising as it is, there are many people who are quite happy without TypeScript in their lives (I know - mad right?). These poor unfortunates are unlikely to ever take the extra steps necessary to write definition files. For this reason, there will probably always be a need for a provider of typings such as Definitely Typed. As well as that, the vast majority of people using TypeScript probably don't use npm to manage dependencies. There are, however, an increasing number of users who are using npm. Some (like me) may even be using tools like Browserify (with the TSIFY plugin) or WebPack (with the TS loader) to bring it all together. My feeling is that, over time, using npm will become more common; particularly given the improvements being made to module resolution in the language.

An advantage of shipping typings with an npm package is this: those typings should accurately describe their accompanying package. In Definitely Typed we only aim to support the latest and greatest typings. So if you find yourself looking for the typings of an older version of a package you're going to have to pick your way back through the history of a .d.ts file and hope you happen upon the version you're looking for. Not a fantastic experience.

So I guess what I'm saying is this: if you're an npm package author then it would be fantastic to start shipping a package with typings in the box. If you're using npm to consume packages then using Definitely Typed ought to be the second step you might take after installing a package; the step you only need to take if the package doesn't come with typings. Using DT should be a fallback, not a default.

Authoring npm modules with TypeScript

Yup - that's what this post is actually about. See how I lured you in with my mild trolling and pulled the old switcheroo? That's edutainment my friend. So, how do we write npm packages in TypeScript and publish them with their typings? Apparently Gandhi didn't actually say "Be the change you wish to see in the world." Which is a shame. But anyway, I'm going to try and embrace the sentiment here.

Not so long ago I wrote a small npm module called globalize-so-what-cha-want. It is used to determine what parts of Globalize 1.x you need depending on the modules you're planning to use. It also, contains a little demo UI / online tool written in React which powers this.

For this post, the purpose of the package is rather irrelevant. And even though I've just told you about it, I want you to pretend that the online tool doesn't exist. Pretend I never mentioned it.

What is relevant, and what I want you to think about, is this: I wrote globalize-so-what-cha-want in plain old, honest to goodness JavaScript. Old school.

But, my love of static typing could be held in abeyance for only so long. Once the initial package was written, unit tested and published I got the itch. THIS SHOULD BE WRITTEN IN TYPESCRIPT!!! Well, it didn't have to be but I wanted it to be. Despite having used TypeScript since the early days I'd only been using it for front end work; not for writing npm packages. My mission was clear: port globalize-so-what-cha-want to TypeScript and re-publish to npm.

Port, port, port!!!

At this point globalize-so-what-cha-want consisted of a single index.js file in the root of the package. My end goal was to end up with that file still sat there, but now generated from TypeScript. Alongside it I wanted to see a index.d.ts which was generated from the same TypeScript.

index.js before looked like this:

/* jshint varstmt: false, esnext: false */
var DEPENDENCY_TYPES = {
  SHARED_JSON: 'Shared JSON (used by all locales)',
  LOCALE_JSON: 'Locale specific JSON (supplied for each locale)'
};

var moduleDependencies = {
  'core': {
    dependsUpon: [],
    cldrGlobalizeFiles: ['cldr.js', 'cldr/event.js', 'cldr/supplemental.js', 'globalize.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/likelySubtags.json' }
    ]
  },

  'currency': {
    dependsUpon: ['number','plural'],
    cldrGlobalizeFiles: ['globalize/currency.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/currencies.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/currencyData.json' }
    ]
  },

  'date': {
    dependsUpon: ['number'],
    cldrGlobalizeFiles: ['globalize/date.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/ca-gregorian.json' },
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/timeZoneNames.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/timeData.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/weekData.json' }
    ]
  },

  'message': {
    dependsUpon: ['core'],
    cldrGlobalizeFiles: ['globalize/message.js'],
    json: []
  },

  'number': {
    dependsUpon: ['core'],
    cldrGlobalizeFiles: ['globalize/number.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/numbers.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/numberingSystems.json' }
    ]
  },

  'plural': {
    dependsUpon: ['core'],
    cldrGlobalizeFiles: ['globalize/plural.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/plurals.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/ordinals.json' }
    ]
  },

  'relativeTime': {
    dependsUpon: ['number','plural'],
    cldrGlobalizeFiles: ['globalize/relative-time.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/dateFields.json' }
    ]
  }
};

function determineRequiredCldrData(globalizeOptions) {
  return determineRequired(globalizeOptions, _populateDependencyCurrier('json', function(json) { return json.dependency; }));
}

function determineRequiredCldrGlobalizeFiles(globalizeOptions) {
  return determineRequired(globalizeOptions, _populateDependencyCurrier('cldrGlobalizeFiles', function(cldrGlobalizeFile) { return cldrGlobalizeFile; }));
}

function determineRequired(globalizeOptions, populateDependencies) {
  var modules = Object.keys(globalizeOptions);
  modules.forEach(function(module) {
    if (!moduleDependencies[module]) {
      throw new TypeError('There is no \'' + module + '\' module');
    }
  });

  var requireds = [];
  modules.forEach(function (module) {
    if (globalizeOptions[module]) {
      populateDependencies(module, requireds);
    }
  });

  return requireds;
}

function _populateDependencyCurrier(requiredArray, requiredArrayGetter) {
  var popDepFn = function(module, requireds) {
    var dependencies = moduleDependencies[module];

    dependencies.dependsUpon.forEach(function(requiredModule) {
      popDepFn(requiredModule, requireds);
    });

    dependencies[requiredArray].forEach(function(required) {
      var newRequired = requiredArrayGetter(required);
      if (requireds.indexOf(newRequired) === -1) {
        requireds.push(newRequired);
      }
    });

    return requireds;
  };

  return popDepFn;
}

module.exports = {
  determineRequiredCldrData: determineRequiredCldrData,
  determineRequiredCldrGlobalizeFiles: determineRequiredCldrGlobalizeFiles
};

You can even kind of tell that it was written in JavaScript thanks to the jshint rules at the top.

I fired up Atom and created a new folder src/lib and inside there I created index.ts (yes, index.js renamed) and tsconfig.json. By the way, you'll notice I'm not leaving Atom - I'm making use of the magnificent atom-typescript which you should totally be using too. It rocks.

Now I'm not going to bore you with what I had to do to port the JS to TS (not much). If you're interested, the source is here. What's more interesting is the tsconfig.json - as it's this that is going to lead the generation of the JS and TS that we need:

{
    "compileOnSave": true,
    "compilerOptions": {
        "module": "commonjs",
        "declaration": true,
        "target": "es5",
        "noImplicitAny": true,
        "suppressImplicitAnyIndexErrors": true,
        "removeComments": false,
        "preserveConstEnums": true,
        "sourceMap": false,
        "outDir": "../../"
    },
    "files": [
        "index.ts"
    ]
}

The things to notice are:

module
Publishing a commonjs module means it will play well with npm
declaration
This is what makes TypeScript generate index.d.ts
outDir
We want to regenerate the index.js in the root (2 directories above this)

So now, what do we get when we build in Atom? Well, we're generating an index.js file which looks like this:

var DEPENDENCY_TYPES = {
  SHARED_JSON: 'Shared JSON (used by all locales)',
  LOCALE_JSON: 'Locale specific JSON (supplied for each locale)'
};
var moduleDependencies = {
  'core': {
    dependsUpon: [],
    cldrGlobalizeFiles: ['cldr.js', 'cldr/event.js', 'cldr/supplemental.js', 'globalize.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/likelySubtags.json' }
    ]
  },
  'currency': {
    dependsUpon: ['number', 'plural'],
    cldrGlobalizeFiles: ['globalize/currency.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/currencies.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/currencyData.json' }
    ]
  },
  'date': {
    dependsUpon: ['number'],
    cldrGlobalizeFiles: ['globalize/date.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/ca-gregorian.json' },
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/timeZoneNames.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/timeData.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/weekData.json' }
    ]
  },
  'message': {
    dependsUpon: ['core'],
    cldrGlobalizeFiles: ['globalize/message.js'],
    json: []
  },
  'number': {
    dependsUpon: ['core'],
    cldrGlobalizeFiles: ['globalize/number.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/numbers.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/numberingSystems.json' }
    ]
  },
  'plural': {
    dependsUpon: ['core'],
    cldrGlobalizeFiles: ['globalize/plural.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/plurals.json' },
      { dependencyType: DEPENDENCY_TYPES.SHARED_JSON, dependency: 'cldr/supplemental/ordinals.json' }
    ]
  },
  'relativeTime': {
    dependsUpon: ['number', 'plural'],
    cldrGlobalizeFiles: ['globalize/relative-time.js'],
    json: [
      { dependencyType: DEPENDENCY_TYPES.LOCALE_JSON, dependency: 'cldr/main/{locale}/dateFields.json' }
    ]
  }
};
function determineRequired(globalizeOptions, populateDependencies) {
  var modules = Object.keys(globalizeOptions);
  modules.forEach(function (module) {
    if (!moduleDependencies[module]) {
      throw new TypeError('There is no \'' + module + '\' module');
    }
  });
  var requireds = [];
  modules.forEach(function (module) {
    if (globalizeOptions[module]) {
      populateDependencies(module, requireds);
    }
  });
  return requireds;
}
function _populateDependencyCurrier(requiredArray, requiredArrayGetter) {
  var popDepFn = function (module, requireds) {
    var dependencies = moduleDependencies[module];
    dependencies.dependsUpon.forEach(function (requiredModule) {
      popDepFn(requiredModule, requireds);
    });
    dependencies[requiredArray].forEach(function (required) {
      var newRequired = requiredArrayGetter(required);
      if (requireds.indexOf(newRequired) === -1) {
        requireds.push(newRequired);
      }
    });
    return requireds;
  };
  return popDepFn;
}
/**
 * The string array returned will contain a list of the required cldr json data you need. I don't believe ordering matters for the json but it is listed in the same dependency order as the cldr / globalize files are.
 *
 * @param options The globalize modules being used.
 */
function determineRequiredCldrData(globalizeOptions) {
  return determineRequired(globalizeOptions, _populateDependencyCurrier('json', function (json) { return json.dependency; }));
}
exports.determineRequiredCldrData = determineRequiredCldrData;
/**
 * The string array returned will contain a list of the required cldr / globalize files you need, listed in the order they are required.
 *
 * @param options The globalize modules being used.
 */
function determineRequiredCldrGlobalizeFiles(globalizeOptions) {
  return determineRequired(globalizeOptions, _populateDependencyCurrier('cldrGlobalizeFiles', function (cldrGlobalizeFile) { return cldrGlobalizeFile; }));
}
exports.determineRequiredCldrGlobalizeFiles = determineRequiredCldrGlobalizeFiles;

Aside from one method moving internally and me adding some JSDoc, the only really notable change is the end of the file. TypeScript, when generating commonjs, doesn't use the module.exports = {} approach. Rather, it drops exported functions onto the exports object as functions are exported. Functionally this is identical.

Now for our big finish: happily sat alongside is index.js is the index.d.ts file:

export interface Options {
  currency?: boolean;
  date?: boolean;
  message?: boolean;
  number?: boolean;
  plural?: boolean;
  relativeTime?: boolean;
}
/**
 * The string array returned will contain a list of the required cldr json data you need. I don't believe ordering matters for the json but it is listed in the same dependency order as the cldr / globalize files are.
 *
 * @param options The globalize modules being used.
 */
export declare function determineRequiredCldrData(globalizeOptions: Options): string[];
/**
 * The string array returned will contain a list of the required cldr / globalize files you need, listed in the order they are required.
 *
 * @param options The globalize modules being used.
 */
export declare function determineRequiredCldrGlobalizeFiles(globalizeOptions: Options): string[];

We're there, huzzah! This has been now published to npm - anyone consuming this package can use TypeScript straight out of the box. I really hope that publishing npm packages in this fashion becomes much more commonplace. Time will tell.

PS I'm not the only one

I was just about to hit "publish" when I happened upon Basarat's ts-npm-module which is a project on GitHub which demo's how to publish and consume TypeScript using npm. I'd say great minds think alike but I'm pretty sure Basarat's mind is far greater than mine! (Cough, atom-typescript, cough.) Either way, it's good to see validation for the approach I'm suggesting.

PPS Update 23/09/2015 09:51

One of the useful things about writing a blog is that you get to learn. Since I published I've become aware of a few things somewhat relevant to this post. First of all, there is still work ongoing in TypeScript land around this topic. Essentially there are problems resolving dependency conflicts when different dependencies have different versions - you can take part in the ongoing discussion here. There's also some useful resources to look at:

Thursday, 10 September 2015

Things Done Changed

Some people fear change. Most people actually. I'm not immune to that myself, but not in the key area of technology. Any developer that fears change when it comes to the tools and languages that he / she is using is in the wrong business. Because what you're using to cut code today will not last. The language will evolve, the tools and frameworks that you love will die out and be replaced by new ones that are different and strange. In time, the language you feel you write as a native will fall out of favour, replaced by a new upstart.

My first gig was writing telecoms software using Delphi. I haven't touched Delphi (or telecoms for that matter) for over 10 years now. Believe me, I grok that things change.

That is the developer's lot. If you're able to accept that then you'll be just fine. For my part I've always rather relished the new and so I embrace it. However, I've met a surprising number of devs that are outraged when they realise that the language and tools they have used since their first job are not going to last. They do not go gentle into that good dawn. They rage, rage against the death of WebForms. My apologies to Dylan Thomas.

I recently started a new contract. This always brings a certain amount of change. This is part of the fun of contracting. However, the change was more significant in this case. As a result, the tools that I've been using for the last couple of months have been rather different to those that I'm used to. I've been outside my comfort zone. I've loved it. And now I want to reflect upon it. Because, in the words of Socrates, "the unexamined life is not worth living".

The Shock of the New (Toys)

I'd been brought in to work on a full stack ASP.Net project. However, I've initially been working on a separate project which is entirely different. A web client app which has nothing to do with ASP.Net at all. It's a greenfield app which is built using the following:

  1. React / Flux
  2. WebSockets / Protocol Buffers
  3. Browserify
  4. ES6 with Babel
  5. Karma
  6. Gulp
  7. Atom

Where to begin? Perhaps at the end - Atom.

How Does it Feel to be on Your Own?

When all around you, as far as the eye can see, are monitors displaying Visual Studio in all its grey glory whilst I was hammering away on Atom. It felt pretty good actually.

The app I was working on was a React / Flux app. You know what that means? JSX! At the time the project began Visual Studio did not have good editor support for JSX (something that the shipping of VS 2015 may have remedied but I haven't checked). So, rather than endure a life dominated with red squigglies I jumped ship and moved over to using GitHub's Atom to edit code.

I rather like it. Whilst VS is a full blown IDE, Atom is a text editor. A very pretty one. And crucially, one that can be extended by plugins of which there is a rich ecosystem. You want JSX support? There's a plugin for that. You want something that formats JSON nicely for you? There's a plugin for that too.

My only criticism of Atom really is that it doesn't handle large files well and it crashes a lot. I'm quite surprised by both of these characteristics given that in contrast to VS it is so small. You'd think the basics would be better covered. Go figure. It still rocks though. It looks so sexy - how could I not like it?

Someone to watch over me

I've been using Gulp for a while now. It's a great JavaScript task runner and incredibly powerful. Previously though, I've used it as part of a manual build step (even plumbing it into my csproj). With the current project I've moved over to using the watch functionality of gulp. So I'm scrapping triggering gulp tasks manually. Instead we have gulp configured to gaze lovingly at the source files and, when they change, re-run the build steps.

This is nice for a couple of reasons:

  • When I want to test out the app the build is already done - I don't have to wait for it to happen.
  • When I do bad things I find out faster. So I've got JSHint being triggered by my watch. If I write code that makes JSHint sad (and I haven't noticed the warnings from the atom plugin) then they'll appear in the console. Likewise, my unit tests are continuously running in response to file changes (in an ncrunch-y sorta style) and so I know straight away if I'm breaking tests. Rather invaluable in the dynamic world of JavaScript.

Karma, Karma, Karma, Chameleon

In the past, when using Visual Studio, it made sense to use the mighty Chutzpah which allows you to run JS unit tests from within VS itself. I needed a new way to run my Jasmine unit tests. The obvious choice was Karma (built by the Angular team I think?). It's really flexible.

You're using Browserify? No bother. You're writing ES6 and transpiling with Babel? Not a problem. You want code coverage? That we can do. You want an integration for TeamCity? That too is sorted....

Karma is fantastic. Fun fact: originally it was called Testacular. I kind of get why they changed the name but the world is all the duller for it. A side effect of the name change is that due to invalid search results I know a lot more about Buddhism than I used to.

I cry Babel, Babel, look at me now

Can you not wait for the future? Me neither. Even though it's 2015 and Back to the Future II takes place in only a month's time. So I'm not waiting for a million and one browsers to implement ES6 and IE 8 to finally die dammit. Nope, I have a plan and it's Babel. Transpile the tears away, write ES6 and have Babel spit out EStoday.

I've found this pretty addictive. Once you've started using ES6 features it's hard to go back. Take destructuring - I can't get enough of it.

Whilst I love Babel, it has caused me some sadness as well. My beloved TypeScript is currently not in the mix, Babel is instead sat squarely where I want TS to be. I'm without static types and rather bereft. You can certainly live without them but having done so for a while I'm pretty clear now that static typing is a massive productivity win. You don't have to hold the data structures that you're working on in your head so much, code completion gives you what you need there, you can focus more on the problem that you're trying to solve. You also burn less time on silly mistakes. If you accidentally change the return type of a function you're likely to know straight away. Refactoring is so much harder without static types. I could go on.

All this goes to say: I want my static typing back. It wasn't really an option to use TypeScript in the beginning because we were using JSX and TS didn't support it. However! TypeScript is due to add support for JSX in TS 1.6 (currently in beta). I've plans to see if I can get TypeScript to emit ES6 and then keep using Babel to do the transpilation. Whether this will work, I don't know yet. But it seems likely. So I'm hoping for a bright future.

Browserify (there are no song lyrics that can be crowbarred in)

Emitting scripts in the required order has been a perpetual pain for everyone in the web world for the longest time. I've taken about 5 different approaches to solving this problem over the years. None felt particularly good. So Browserify.

Browserify solves the problem of script ordering for you by allowing you to define an entry point to your application and getting you to write require (npm style) or import (ES6 modules) to bring in the modules that you need. This allows Browserify (which we're using with Babel thanks to the babelify transform) to create a ginormous js file that contains the scripts served as needed. Thanks to the magic of source maps it also allows us to debug our original code (yup, the original ES6!) Browserify has the added bonus of allowing us free reign to pull in npm packages to use in our app without a great deal of ceremony.

Browserify is pretty fab - my only real reservation is that if you step outside the normal use cases you can quickly find yourself in deep water. Take for instance web workers. We were briefly looking into using them as an optimisation (breaking IO onto a separate process from the UI). A prime reason for backing away from this is that Web Workers don't play particularly well with Browserify. And when you've got Babel (or Babelify) in the mix the problems just multiply. That apart, I really dig Browserify. I think I'd like to give WebPack a go as well as I understand it fulfills a similar purpose.

WebSockets / Protocol Buffers

The application I'm working on is plugging into an existing system which uses WebSockets for communication. Since WebSockets are native to the web we've been able to plumb these straight into our app. We're also using Protocol Buffers as another optimisation; a way to save a few extra bytes from going down the wire. I don't have much to say about either, just some observations really:

  1. WebSockets is a slightly different way of working - permanently open connections as opposed to the request / response paradigm of classic HTTP
  2. WebSockets are wicked fast (due in part to those permanent connections). So performance is amazing. Fast like native, type amazing. In our case performance is pretty important and so this has been really great.

React / Flux

Finally, React and Flux. I was completely new to these when I came onto the project and I quickly came to love them. There was a prejudice for me to overcome and that was JSX. When I first saw it I felt a little sick. "Have we learned NOTHING???" I wailed. "Don't we know that embedding strings in our controllers is a BAD thing?" I was wrong. I had an epiphany. I discovered that JSX is not, as I first imagined, embedded HTML strings. Actually it's syntactic sugar for object creation. A simple example:

var App;

// Some JSX:
var app = <App version="1.0.0" />;

// What that JSX transpiles into:
var app = React.createElement(App, {version:"1.0.0"});

Now that I'm well used to JSX and React I've really got to like it. I keep my views / components as dumb as possible and do all the complex logic in the stores. The stores are just standard JavaScript and so, pretty testable (simple Jasmine gives you all you need - I haven't felt the need for Jest). The components / views are also completely testable. I'd advise anyone coming to React afresh to make use of the ReactShallowRenderer for these purposes. This means you can test without a DOM - much better all round.

I don't have a great deal to say about Flux; I think my views on it aren't fully formed yet. I do really like predictability that unidirectional data flow gives you. However, I'm mindful that the app that I've been writing is very much about displaying data and doesn't require much user input. I know that I'm living without 2-way data binding and I do wonder if I would come to miss it. Time will tell.

I really want to get back to static typing. That either means TypeScript (which I know and love) or Facebook's Flow. (A Windows version of Flow is in the works.) I'll be very happy if I get either into the mix... Watch this space.