Jsxcore publish node modules

Title

First dotnet publish on a clean checkout omits node_modules from the output

Body

On a clean checkout the packages are restored during the publish and end up absent from its output, so the published application cannot resolve them at runtime. A second publish includes them.

docs/build-and-deploy.md says:

Everything in your dependencies is copied into the publish output automatically

which is what happens on the second publish. The first is the one CI and container builds always do.

Reproduction

.NET SDK 9.0.316, JsxCore 1.0.0, in mcr.microsoft.com/dotnet/sdk:9.0 with no Node and no npm installed. Three packages in dependencies:

"dependencies": {
  "marked": "^18.0.9",
  "dayjs": "^1.11.21",
  "highlight.js": "^11.11.1"
}

# clean checkout - no node_modules yet
rm -rf src/MyApp/node_modules

dotnet publish src/MyApp/MyApp.csproj -c Release -o /tmp/pub1
#   JsxCore: restoring with native: typescript, esbuild, marked, dayjs, highlight.js
#   JsxCore: fetching ...

ls /tmp/pub1/node_modules        # -> does not exist
ls src/MyApp/node_modules        # -> restored here: dayjs, highlight.js, marked, ...

# second publish, nothing to restore
dotnet publish src/MyApp/MyApp.csproj -c Release -o /tmp/pub2
ls /tmp/pub2/node_modules        # -> dayjs  highlight.js  marked   (dependencies only)

Same result with and without --no-restore. The deciding factor is whether node_modules already existed when publish started.

Why it bites

A Dockerfile or CI job is a clean checkout by definition, so it always hits the first case. The build succeeds, the image builds, the app starts, and every view importing a package returns 500:

JsxCore.JsxRenderException: JsxCore failed to server-render 'Journey/Chapter'.
 ---> JsxCore.JsxCoreException: JsxCore could not resolve the module 'marked' during
      server rendering. It was not found in node_modules. Searched:

The startup warning is genuinely helpful and is how I found it. Thank you for writing it:

JsxCore: package.json declares marked, dayjs, highlight.js, which are not installed in /app. A view importing one will fail to render. Build again to restore them.

"Build again to restore them" is exactly right and exactly what a container image cannot do.

Workaround

Copying them explicitly in the final stage:

COPY --from=build /src/src/MyApp/node_modules ./node_modules

Guess at the cause

It looks like the item group that carries node_modules into the publish output is evaluated before the restore target populates the directory, so on the run that performs the restore the glob matches nothing. I have not read the targets closely enough to be confident, so treat that as a hint rather than a diagnosis.

Happy to open a PR if you can point me at the right target.

---

Notes for me, not for the issue

• Verified on main docs and JsxCore 1.0.0 from NuGet.
• I originally wrote this up as "publish does not copy node_modules", which was wrong - it does, on the second run. Isolating clean-vs-warm was what made it a real report. Chapter 7 was corrected to match.
• Lead with the repro, not the theory. The cause guess is at the bottom and hedged because I did not verify it.