override prompts with command line arguments

[navtoj]

This adds support for automatically answering the interactive prompts in environments where manual entry is not possible; e.g. scripts, batch runs, etc.

Before

npm create svelte@latest project_directory

After

npm create svelte@latest project_directory --template=skeleton --types=typescript --eslint=true --prettier=true --playwright=true --overwrite=true

All arguments are optional.

• --template= default, libskeleton, or skeleton

• --types= checkjs or typescript

• --eslint= true or false

• --prettier= true or false

• --playwright= true or false

• --overwrite= true or false

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• This message body should clearly illustrate what problems it solves.
• Ideally, include a test that fails without this PR but passes with it.

Tests

• Run the tests with pnpm test and lint the project with pnpm lint and pnpm check

Changesets

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[Conduitry]

Thank you for the PR. This has come up several times before, though, and is something we're not comfortable with for a couple reasons. If someone is running the CLI, they're likely going to always be pulling down the latest version, and we may occasionally add additional questions to the script. If they don't specify an option for one of them, what happens? Does the script suddenly become interactive again? If the user specifies at least one option, do we make assumptions about all of the other ones based on some default? If we reorganize some of the prompts, what do we do with CLI args that are now invalid? Any path we take here seems suboptimal.

As a compromise, the create-svelte package also exposes a programmatic API, which will respect semver (once SvelteKit is in general release). Any new prompts that must be answered will be a major version bump. Anything that changes the output in a way that's not a clear backwards-compatible improvement will also be a major version bump. If you need automated access to bootstrapping new projects, you can write a tiny script that calls this API and depends on create-svelte like it would any other dependency, with all the benefits of semver. And the majority of people - those just calling the CLI - will continue to get the latest one (no matter what its semver major version number is) and can just response to the prompts.

[JReinhold]

For anyone landing here, the Storybook team has released a community solution to this called create-svelte-with-args. It is a small CLI wrapper around create-svelte that allows you to create SvelteKit projects without the interactive prompts.

@Conduitry I've tried to be very explicit in the documentation stating that create-svelte-with-args is not supported nor endorsed by the Svelte core team. The last thing we want is for this to become a burden for you as maintainers because you've stated some very valid arguments above as to why you don't want to support this officially. Let me know if you have any thoughts on this.