Tad Website - Tad Blog

The plan for a co-op

Tad Lispy — Fri, 21 Mar 2025 00:00:00 +0000

A hopeful sci-fi story in which I invite you to join a network of smart and kind professionals, who support one another both in their work and personally 🧑‍🚀 We want to set up a co-operative sometime within the next 12 months and conquer the world with our kindness within 10 years. What brings us together and guides our efforts is our shared desire for fairness and freedom, and our concern about dependence on big tech oligopolies 👾 That's why we want to support businesses in a transition to free software and European digital services.

Guiding principles for a co-op

Tad Lispy — Thu, 20 Mar 2025 00:00:00 +0000

So it really seems like I am starting a business</a> with a bunch of beautiful strangers. What a fantastic feeling! The kind and sometimes weird interactions I had with you over the past two weeks inspired me to get to work early every morning. And now that we are going to work together, we need to figure out how to do it.

Tad Co-op

Tad Lispy — Sun, 16 Mar 2025 00:00:00 +0000

I wrote the following manifesto as a guide to how and with whom I want to work. It's my personal statement, and I have no right to impose it on anyone else, but if you significantly disagree with any part of it, then we probably shouldn't work together. That is unless you can change my mind first.

Why is `this` so terrible

Tad Lispy — Thu, 16 Jan 2020 00:00:00 +0000

Recently at a meetup in Utrecht I gave a short presentation: Elements of Functional Programming for React.js Developers. See the slides</a>.

Shape Up by Ryan Singer from Basecamp

Tad Lispy — Tue, 27 Aug 2019 00:00:00 +0000

2024 Update: To large extent Software Garden</a> was an attempt to implement the ideas from Singer's book, but adapted to working with clients. </blockquote>
Oh my! This book is the best. I want to work like that! You can read the book here</a>.

Is there an equivalent of `cd -` for `cp` or `mv`?

Tad Lispy — Sun, 31 Mar 2019 00:00:00 +0000

Perhaps you know that in Unix shell you can go back and forth between current and previous directory using handy shortcut for the cd</code> command:
cd -</code></pre>
But this is cd</code> specific. Is there a way to copy or move a file from current directory to the previous? Turns out there is. Read more</a>.
Using `Promise.race` in Node.js to enforce a timeout Tad Lispy — Fri, 04 Aug 2017 00:00:00 +0000 It is a little bit more tricky than this: const task = new Promise((resolve, reject) => setTimeout(resolve, 5000, 'done') ) const timeout = new Promise((resolve, reject) => setTimeout(reject, 100, 'timed out') ) Promise .race([ timeout, task ]) .then(console.log) .catch(console.error);</code></pre> If you run this, you will find out that the process terminates only after both promises are done (i.e. after around 5 seconds): $ time node src/race.js timed out node src/race.js 0,36s user 0,03s system 7% cpu 5,370 total</code></pre> In fact, if one of them is never resolved (and that's exactly what we expect, otherwise we would not introduce a timeout here), the process will hang forever. Seems like `Promise.race` is not doing a proper cleanup. The `task` promise remains pending (event though it's eventual value will never propagate through the chain). This makes the runtime wait for it's resolution before it terminates. Unfortunately I don't know of any elegant workaround for this. Currently I simply call `process.exit` somewhere down the chain: Promise .race([ timeout, task ]) .then(console.log) .catch(console.error); .then(process.exit)</code></pre> In my book it's not an elegant solution. Passing `undefined` to a JavaScript promise Tad Lispy — Fri, 04 Aug 2017 00:00:00 +0000 Consider this simple snippet: Promise .resolve('JavaScript, why are you doing this to me?') .then(console.logg) .catch(console.error)</code></pre> Note that console.logg</code> is undefined</code>. What will be printed? Nothing. The promise will silently resolve to the value of 'JavaScript, why are you doing this to me?'</code></pre> Which is a good question. I think it's because it hates me. It's obviously a developer's mistake. My first thought was that introducing type system (like Flow) would solve this - and it would. But why isn't then</code> method of a Promise</code> just throwing a type error as soon as anything other than function</code> is passed to it? This leads to silent and hard to spot bugs. Unfortunately in JS community there is a strong attitude of ignoring the errors and going on as if nothing ever happened. Weird AWS region bug Tad Lispy — Fri, 04 Aug 2017 00:00:00 +0000 I've been fighting a weird error coming from AWS SDK for Node.js: ConfigError: Missing region in config</code></pre> I was setting the region like that: // Setup AWS SDK const AWS = require('aws-sdk'); AWS.config.update({ region: aws_region });</code></pre> Turns out that despite the fact that AWS is a singleton, it's config passed to service instances is not. What is a service instance. E.g. this: new AWS.SQS()</code></pre> In other words, SQS instance will have it's config baked in, and subsequent changes to AWS.config won't affect it. So the order of execution is important. Consider: AWS.config.update({ region: A }) const sqs = new AWS.SQS() AWS.config.update({ region: B }) sqs.sendMessage(...) // the region from the sqs perspective is A!</code></pre> Running Facebook's Flow in an Alpine Node Container Tad Lispy — Fri, 21 Jul 2017 00:00:00 +0000 Create a Dockerfile</code> and an npmrc</code> template Creating the Dockerfile was more chalanging than expected. To make flow work in Alpine we need glibc</code>. To get glibc from GitHub we need wget</code> with SSL support (and ca-certs). All in all this Dockerfile</code> works: FROM node:8-alpine # Install bash (required by scripts/*) and GNU wget RUN apk update \ && apk add \ bash \ wget \ ca-certificates # Install glibc comaptibility for alpine (required by flow) RUN wget \ --quiet \ --output-document=/etc/apk/keys/sgerrand.rsa.pub \ https://raw.githubusercontent.com/sgerrand/alpine-pkg-glibc/master/sgerrand.rsa.pub \ && wget \ --quiet \ https://github.com/sgerrand/alpine-pkg-glibc/releases/download/2.25-r0/glibc-2.25-r0.apk \ && apk add glibc-2.25-r0.apk # Slim the image by removing APK cache RUN rm -rf /var/cache/apk/* USER node # This build time argument should be passed by build script. # See common.sh, jenkins-build.sh and .npmrc files ARG npm_token WORKDIR /home/node COPY package.json ./ COPY package-lock.json ./ COPY .flowconfig ./.flowconfig COPY npmrc.template ./.npmrc COPY src ./src COPY scripts ./scripts RUN npm install RUN rm ./.npmrc CMD npm start</code></pre> Sources: https://github.com/facebook/flow/issues/3649</a></li> https://github.com/google/cadvisor/issues/1131</a></li> </ul> How to Setup SSH Key limited to Creating a Tunnel Tad Lispy — Thu, 20 Jul 2017 00:00:00 +0000 For a given key I was intending to prevent any interaction except for starting an SSH tunnel to a particular local port. Turns out that for each key in ~/.ssh/authorized_keys</code> you can add so called login options, by preppending them to the key, like that: option="value",option-without-value,another-option <KEY ...> <COMMENT></code></pre> This combination of options seem to do the trick: command="",restrict,port-forwarding,permitopen="localhost:80"</code></pre> Let me go through each of them individually: command=""</code> disallows any command to be executed using this key </li> restrict</code> Disable all options, such as TTY allocation, port forwarding, agent forwarding, user-rc, and X11 forwarding all at once. </li> port-forwarding</code> Enables TCP port forwarding, but see below. </li> permitopen="localhost:80"</code> Limits TCP port forwarding to local port 80</code>. That's the only thing this key should allow. </li> </ul> So in total it's: command="",restrict,port-forwarding,permitopen="localhost:80" ssh-rsa AAAAB3NzaC1yc2EAAA[...]3c7rmJT5/ tunnel@a.example.com</code></pre> Make sure it's all in one line and there are is no whitespace between the options. I've been able to figure this out mainly by reading Client Configuration Files chapter of OpenSSH WikiBook</a>, so the majority of credit goes to it's authors (Lars Noodén et al.). Missing part was port-forwarding</code> - without it forwarding is forbidden even though permitopen</code> would suggest otherwise. Here is some more background: https://superuser.com/a/1231232/195460</a> Managing access to private NPM repositories Tad Lispy — Thu, 29 Jun 2017 00:00:00 +0000 Make private package accessible to members of deployment team from command line: npm access grant read-only your-organisation:deployment @your-organisation/your-package</code></pre> How to Test if a Given Value is a React.js Component Tad Lispy — Wed, 29 Jul 2015 00:00:00 +0000 2024 Update: Some links to external content are unfortunately outdated. The content in this post doesn't seem relevant to me anymore, except for archival reasons, so I'm not going to update those broken links. </blockquote> It may seem trivial, but it's a bit tricky to test for that. The documentation for React's Test Utils1</a> is lacking examples (as of the time of writing). By comparing it with Virtual DOM glossary2</a> one can assume that instantiating it with new keyword and then checking with TestUtils.isCompositeComponent</code> is a way to go. That's how I do it in CoffeScript: it "is a react component", -> # ReactComponents can be instantiated with new keyword for test purposes # See https://facebook.github.io/react/docs/glossary.html#react-components expect (TestUtils.isCompositeComponent new CheckboxSelect) .to.be.ok</code></pre> ^{1 Broken link to https://facebook.github.io/react/docs/test-utils.html </div> ^{2 Broken link to https://facebook.github.io/react/docs/glossary.html#react-components </div>}} An idea for a blog Tad Lispy — Sun, 12 Jul 2015 00:00:00 +0000 Obviously I have this, or some other idea for a long while. Now it's time to pinpoint it. The blog will be about web craftsmanship. I want to write on regular basis (no less then once a week) about things I'm learning in this field. I want to create and maintain my own engine for this. The reasons are: it will be a nice playground development, </li> I will have everything my way. </li> I will be able to write about developing my blog on my blog. </li> </ul> Technical considerations</h1> Isomorphic app Rendered to static files on build time. Raw markdown and metadata should be hosted along compiled HTML for client side routing and rendering. </li> Adhere to progressive enhancement principles </li> Git integrated Both engine and content should be version controlled. There should be two separate repos. Eventually I want to post and update via git push</code>. As much metadata as possible should be gathered from repo. This would ideally include: Publication date (i.e. the date given post was merged to master</a>?)</li> Editing history</li> Authors (if there were changes merged from pull requests)</li> </ul> </li> </ul> Nice to have features</h1> Twitter integration Display my tweets and retweets in a feed among blog posts. Post updates to Twitter automatically. </li> Stack Exchange integration Display my Stack Exchange activity (questions and answers) in a feed among blog posts. </li> </ul> How to Install NPM Packages Written in CoffeeScript from a Git Repo Tad Lispy — Tue, 28 Apr 2015 00:00:00 +0000 2024 Update: Some links to external content are unfortunately outdated. The content in this post doesn't seem relevant to me anymore, except for archival reasons, so I'm not going to update those broken links. </blockquote> 2017 update: Working on this problem eventually lead me to create npm-git-install</a> helper. The program should not be needed since the introduction of the prepare</code> NPM script</a>. </blockquote> IDEA: Use npm install</code> script with value same as prepublish</code>, but this would have to be changed before publishing to registry. It is said to be an anti-pattern See https://docs.npmjs.com/misc/scripts#common-uses</del> (broken link) An issue by isaacs run prepublish</code> for git url packages</a> Installing it from a directory (../package/</code>) runs prepublish</code>. WTF? IDEA: Make a gitinstall gulp task, which will: npm install (to get dev dependencies)</li> run build task</li> </ul> </blockquote> Would it be possible use .npmignore then? The problem is that gulp is in dev-dependencies. So npm install has to be in install script, which seems a little strange. Result: endless loop (npm install triggers install script; obviously). NOTE: Installing from local directory triggers prepublish </blockquote> Maybe installing from git should work like that: clone to tmp dir</li> install from tmp dir</li> remove tmp dir</li> </ol> This doesn't seem very hard to do.

Tad Website - Tad Blog

The plan for a co-op

Guiding principles for a co-op

Tad Co-op

Why is `this` so terrible

Shape Up by Ryan Singer from Basecamp

Is there an equivalent of `cd -` for `cp` or `mv`?

Using `Promise.race` in Node.js to enforce a timeout

Passing `undefined` to a JavaScript promise

Weird AWS region bug

Running Facebook's Flow in an Alpine Node Container

How to Setup SSH Key limited to Creating a Tunnel

Managing access to private NPM repositories

How to Test if a Given Value is a React.js Component

An idea for a blog

Technical considerations</h1> Isomorphic app</p> Rendered to static files on build time. Raw markdown and metadata should be hosted along compiled HTML for client side routing and rendering.</p> </li> Adhere to progressive enhancement</em> principles</p> </li>

Nice to have features</h1> Twitter integration</p> Display my tweets and retweets in a feed among blog posts.</p> Post updates to Twitter automatically.</p> </li> Stack Exchange integration</p> Display my Stack Exchange activity (questions and answers) in a feed among blog posts.</p> </li> </ul>

How to Install NPM Packages Written in CoffeeScript from a Git Repo

Nice to have features</h1>

Twitter integration</p>
Display my tweets and retweets in a feed among blog posts.</p>
Post updates to Twitter automatically.</p> </li>

Stack Exchange integration</p>
Display my Stack Exchange activity (questions and answers) in a feed among blog posts.</p> </li> </ul>