TIL

I use Ripgrep as my command-line search tool. Something I often want is to return matching filenames only, instead of Ripgrep’s rich colored output, so I can pipe them to xargs. Here’s that flag: rg -l The -l flag is short for the --files-with-matches flag. As an example, today I used it to delete all drafts from a blog project. rg -l "draft" src/content/posts/ | xargs rm See man rg for more.

For each way you can map something in Vim, you can inspect those mappings. Check out this table of commands: COMMANDS MODES :map :noremap :unmap Normal, Visual, Select, Operator-pending :nmap :nnoremap :nunmap Normal :vmap :vnoremap :vunmap Visual and Select :smap :snoremap :sunmap Select :xmap :xnoremap :xunmap Visual :omap :onoremap :ounmap Operator-pending :map! :noremap! :unmap! Insert and Command-line :imap :inoremap :iunmap Insert :lmap :lnoremap :lunmap Insert, Command-line, Lang-Arg :cmap :cnoremap :cunmap Command-line :tmap :tnoremap :tunmap Terminal-Job To take a very practical one, :nmap will show you all of your normal mode mappings. Find a new command to try; you are not using them all (neither am I). ...

We can save all evaluated commands from our TSX REPL session to a file: $ npx tsx > const name: number = "Jake" undefined > .save output.ts Session saved to: output.ts One use case would be evaluating that output with tsc to get compilation and type-checking: $ npx tsc output.ts output.ts:1:7 - error TS2322: Type 'string' is not assignable to type 'number'. 1 const name: number = "Jake" ~~~~~~~~ Found 1 error in output.ts:1 See .help inside TSX for more info about this and other meta commands. ...

Want to get better at technical writing? I’ve been writing prose (READMEs, wikis, and this blog) with Vale for months. It’s helps me write better, faster. Here’s what I’ve learned. Vale is a “linter for prose.” It gives you tips like this. $ vale README.md README.md 4:3 error Did you really mean 'existant'? Vale.Spelling 6:12 warning Use 'use' instead of 'utilize'. Microsoft.Vocab 9:1 suggestion In general, use active voice. write-good.Passive ✖ 1 error, 1 warning and 1 suggestion in 1 file. It’s running in my text editor with Vim and ALE: ...

Today I discovered tsx, a REPL that evaluates TypeScript. You can run it with npx: npx tsx And it evaluates TypeScript. > const onClick = (input: number):void => input + 1 undefined > onClick(1) 2 It does not check types, so you can run this just fine: > const greeting: number = "Hello world!" // Number, or string? undefined For that, you’ll need a compiler like tsc. tsx can transpile TypeScript, but it does not type-check it. tsx npm

For the golfers out there, we can combine these two lines into one: const items = await getCollection(); return items.sort(); This doesn’t work because sort() is being called on the promise returned by getCollection(): return await getCollection().sort(); // `sort()` runs on the Promise Instead, wrap the await expression in parentheses so sort() is called on the resolved value: return (await getCollection()).sort(); // `sort()` runs on the resolved array Promise documentation - MDN

Astro’s default port is 4321. Like Vite, this project is trying to convey its (rocket-launch) branding, even in this small detail. The proposal for this change includes an interesting argument. By choosing a non-3000 port, the developer’s browser is unlikely to already have a favicon cached. This gives the Astro favicon and branding a solid chance of being seen every time by the developer. Astro 4321 proposal

Node Timeout timers have a private boolean attribute called _destroyed. It tells you if the function has been cleared: timer._destroyed; One way to make it true it is to let the function be called: > const timer = setTimeout(() => { | console.log("Done!"); | }, 5000); > timer._destroyed false // Alive > Done! // Function is called > timer._destroyed // Destroyed 💥 true Another is to call clearTimeout: > const timer = setTimeout(() => { | console.log("We'll destroy before this is called!"); | }, 5000); > clearTimeout(timer) // Destroying the timer undefined > timer._destroyed // Destroyed! 💥 true Timeout class docs

Today I used JavaScript to mass-unsubscribe from a website’s email notifications. Here’s the code, followed by what I did and why. document .querySelectorAll('[role="switch"]') .forEach((element) => element.click()); Today I was interacting with a website that specializes in job postings. To unsubscribe to their emails, you must visit a notifications page and un-check a toggle to opt out of each kind of email you’d like to not receive. Perusing the DOM taught me that each button has a role of “switch.” This JavaScript unsubscribed me from every mailing list in a single line of code. ...

Reflection is an important tool in programming; it lets us examine a language’s structure. Can we reflect in JavaScript? Sort of. Some functions can be reflected with toString(): const one = () => 1; // undefined one.toString(); // '() => 1' Very cool! But native functions only return this: > Math.max.toString() 'function max() { [native code] }' You must read the ECMAScript specification to know what the function is required to do. The actual implementation is written in the JavaScript engine, which for Node is Torque, which is why Node can’t show it via toString().