Hook into Svelte compile pipeline

[vekunz]

I have a rather unusual question. I try to build a "plugin" for Svelte, where I want to hook into the compile pipeline of Svelte.

My use case is that I want to transform a bit of the HTML in the *.svelte files. For this I have to execute the import statements in the script-block also. I tried a Svelte preprocessor and a Vite plugin.

The problem is that I have to get the AST of the source code, but neither the AST parser of the svelte/compile package nor the acorn package directly can handle TypeScript (and the acorn-typescript package does not work also).

My question is if there is any way to hook into the compile pipeline of SvelteKit, after TypeScript has transformed to JavaScript, but before anything is turned into the final JavaScript. Alternatively, I would need a way to get the AST of the Source Code even though TypeScript is present.

[david-plugge]

Take a Look at how https://github.com/svelte-add/svelte-add/blob/main/projects/svelte-add/package.json uses estree-walker for ast mainpulation

[david-plugge]

https://github.com/svelte-add/svelte-add/blob/830a58f693ef5a2e4ecc779fc1032e7273deb144/projects/svelte-add/update.js#L129

[vekunz]

I now use htmlparser2 for parsing the HTML and @typescript-eslint/typescript-estree for parsing the TypeScript. And then dom-serializer to serialize the modified DOM back to HTML. For my use-case this works fine.