Sometimes svelte doesn't find new classes

[tivac]

Expected Behavior

When a new class is added to a CSS file referenced via <link> the @modular-css/svelte plugin should properly pick that up and replace it in markup.

Current Behavior

New classes aren't found until the watcher is restarted.

Possible Solution

Steps to Reproduce (for bugs)

1. Create a component referencing CSS via <link>
2. Start a rollup watcher
3. Add a referenced to a non-existant class in the CSS
4. Add the class in the CSS
5. 🔥 when you try to run the generated code because the {css.<class>} wasn't replaced at build time

Context

Your Environment

Executable	Version
@modular-css/rollup	22.3.0
@modular-css/rollup-rewriter	22.2.0
@modular-css/shortnames	22.1.4
@modular-css/svelte	22.1.4
rollup	1.1.2
npm --version	6.4.1
node --version	10.12.0

OS	Version
Windows 10	14393