Build Customizable, Reusable Project Templates With Node.js

0:00This audio is presented by Hacker Noon, where anyone can learn anything about any technology. Build customizable, reusable project templates with Node. JS. By Lucas Tonelli. At some point in your life you end up with a repo that is the starting point. It has the C pipeline you like, your preferred linting and formatting can fix and THE terraform layout that works like a charm. Then a new project shows up, you clone the base template and spend the next 20 minutes doing find and replace on the project name, ids, the domain name and whatever else is hard coded in there. It works, until you miss a thing and find out your project is failing but is it because of the template or because you missed something. However, AS Mall script and 2NPM packages solve this problem pretty well. Prompt and replace. Instead of hard coding values, you create a template with placeholders, using whatever delimiter is unlikely to show up naturally in your code. Something like sitting in your, terraform files, or any other file. Then a single script asks for each value and rewrites every occurrence across the repo with two

1:03libraries doing the heavy lifting. At inquire, prompts for the questions and replace and file for the replacements. The script the interesting part is that the list of regaxes in is the only place you declare anything. The loop turns each pattern into a question by stripping the delimiters out of the regax source, so becomes, specify the domain underscore name. Adding a new parameter to your template means adding one line to that array, and the prompt comes for free. The array is a placeholder that gets fully overwritten by the answers, and since he thianth answer maps to the nth pattern, order matters. Two other details airworth pointing out, has to include the scaffolder itself. Otherwise the script rewrite's its own regaxes mid run and you get a fun debugging session. Is what makes actually reach the dot files, which is where half of your config lives anyway, and friends, of course, the script and everything else is customizable, so if you have a different idea, set it up in any way you prefer. What about Yomin and CookieCater? This problem is old and there are two well established tools that solve it. SoisFair to ask why you'd write 30 lines instead of using them.

2:08Yomin Yomin is the node ecosystems answer and it's a proper framework. You write a generator as a separate package, it renders templates through EJS, handles conflict resolution when files already exist, composes generators together and can run install steps afterwards. That's genuinely more powerful, but it alsemines your template stops being a repository you can clone and run, and becomes a package you have to publish, version and install globally before anyone can use it. CookieCutter CookieCutter is the Python one and it's closer in spirit. A declares the variables and ginger renders the tree. It renames directories, which is exactly the thing the script above can't do, and it works on any project regardless of language. The tradeoff is that your node template repo now needs Python in every environment that touches it. Limitations. The package is what its name says, it replaces content in files. Pads are out of scope, as I mentioned, so a directory called stays exactly as it is after the script runs, quietly, with no error to tell you about it. However,

3:09there are a few ways to work around it, an increasing order of effort. Keep folder names generic, if possible, law. Rename folders by hand afterwards. Fine for one or two paths, terrible as a convention because it's the exact manual step you were trying to delete. Add a rename pass to the script, walk the tree with, apply the same answers to path names and the matches. Just remember to go depth first, otherwise you rename a parent directory and invalidate every path you were about to visit. You may also have noticed that the replacements themselves are not transactional. If the process dies halfway through, part of your repo IS substituted and part isn't, so run it on a fresh clone with a clean and let be your review step. The script printing which files change helps a lot here, because a parameter that shows up in zero files is almost always a typo in your template rather than an unused variable. Wrap up. This isn't a replacement for Yo-Men or cookie-cater and it doesn't try to be. It's a single file you drop in a repo to turn it into a template, with NO framework to learn, no package to publish and no second language to install.

4:14If you ever outgrow it, the placeholders you already wrote may help with migrating to another tool. Thank you for listening to this Hackernoon story, read by artificial intelligence. Visit Hackernoon.com to read, write, learn and publish.