Inlay hints do not work if there is content before script tag

[BlueGreenMagick]

Describe the bug

Inlay hints do not show up if 1) svelte file does not start immediately with script tag, or 2) instance script appears above module scripts

Reproduction

text
<script lang="ts">
  let a = 1;
</script>

Inlay hints inside instance script(let a[: number] = 1;) do not show up for above code. Even a white space or a newline causes this.

<script lang="ts">
  let a = 1;
</script>

<script lang="ts" context="module">
  let b = 1;
</script>

Inlay hints inside module script(let b[: number] = 1;) do not show up.

Expected behaviour

Inlay hints should show up

System Info

• OS: macOS
• IDE: VSCode

Which package is the issue about?

svelte-language-server

Additional Information, eg. Screenshots

The cause is in this function: https://github.com/sveltejs/language-tools/blob/0f2396e1a567040f5a33a27d6ddd98712a81f0b9/packages/language-server/src/plugins/typescript/features/InlayHintProvider.ts#L91-L93

The problem occurs when source document has content ordered as [A, B, C], and the contents are remapped in generated document to [B, A, C]. Then convertToTargetTextSpan() only contains [A, C] of the generated document, so inlay hints for B is not generated.

In the above example where there is content before instance script, A is the content before script, B is the script, and C is the content after script.