🚀 Feature: Infer --base from existing package.json scripts during migration

[JoshuaKGoldberg]

Bug Report Checklist

• I have tried restarting my IDE and the issue persists.
• I have pulled the latest main branch of the repository.
• I have searched for related issues and found none that matched my issue.

Overview

Right now, if you run npx create-typescript-app in an existing repository made from the template, you always get the standard mode selection:

◆  How much tooling would you like the template to set up for you?
│  ○ everything  The most comprehensive tooling imaginable: sorting, spellchecking, and more!
│  ● common      Bare starters plus testing and automation for all-contributors and releases. (recommended)
│  ○ minimum     Just bare starter tooling: building, formatting, linting, and type checking.
│  ○ prompt      (allow me to customize)
└

But as a convenience, we could set a default value for this based on package.json's scripts. Let's say:

1. If >=3 of the scripts listed under the everything base exist, set the initial value to everything
2. If >=2 of the scripts listed under the common base exist, set the initial value to common

Additional Info

No response

[GV14982]

I'd like to take this, but I'm not quite understanding the potential solution. Could you give me an example please?

[JoshuaKGoldberg]

Absolutely - thanks for asking!

Suppose npx create-typescript-app --mode migrate (or, if running from a local build, node path/to/create-typescript-app/bin/index.js --mode migrate) is run in a directory that includes a package.json with the following "scripts":

{
	"scripts": {
		"build": "tsup",
		"format": "prettier \"**/*\" --ignore-unknown",
		"initialize": "tsx ./src/bin/index.js --mode initialize",
		"lint": "eslint . .*js --max-warnings 0",
		"lint:knip": "knip",
		"lint:md": "markdownlint \"**/*.md\" \".github/**/*.md\" --rules sentences-per-line",
		"lint:package-json": "npmPkgJsonLint .",
		"lint:packages": "pnpm dedupe --check",
		"lint:spelling": "cspell \"**\" \".github/**/*\"",
		"prepare": "husky install",
		"should-semantic-release": "should-semantic-release --verbose",
		"test": "vitest",
		"tsc": "tsc"
	}
}

The migration script could infer that the repo is probably using the "everything" base (https://github.com/JoshuaKGoldberg/create-typescript-app/blob/main/docs/Options.md#base-and-mode). In that case it shouldn't need to ask for which base to use:

create-typescript-app/src/shared/options/augmentOptionsWithExcludes.ts

Lines 135 to 140 in a51c624

	const base =
	options.base ??
	filterPromptCancel<OptionsBase | symbol>(
	await prompts.select({
	initialValue: "common" as OptionsBase,
	message: `How much tooling would you like the template to set up for you?`,

Does that answer what you're looking for?

[GV14982]

Ah yeah, that makes sense! Thanks for the explainer :)

[github-actions]

🎉 This is included in version v1.42.0 🎉

The release is available on:

• GitHub releases
• npm package (@latest dist-tag)

Cheers! 📦🚀