Add a SvelteKit static build strategy to the deploy engine
SvelteKitBuild reads the adapter from package.json. It only accepts @sveltejs/adapter-static and names the adapter it found otherwise, then installs dependencies, runs the build script, and checks the output has an HTML entry (a prerendered index.html or an SPA fallback like 200.html) before handing it to transport. Co-authored-by: Copilot <223556219+Copilot@users.noreply.github.com>
keypair34 committed
Sep 30, 2026 at 14:10 UTC
558bb4d76d2b248c1968f4648714efce3c8fd05c
4 files changed
+253
-1
Cargo.lock
+1
@@ -2624,6 +2624,7 @@ name = "smbcloud-deploy"
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version = "0.5.4"
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dependencies = [
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"anyhow",
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+ "serde_json",
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"smbcloud-model",
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"smbcloud-utils",
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"tempfile",
crates/smbcloud-deploy/Cargo.toml
+1
@@ -14,6 +14,7 @@ categories = ["development-tools", "development-tools::build-utils"]
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[dependencies]
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anyhow = { workspace = true }
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+serde_json = { workspace = true }
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tempfile = { workspace = true }
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thiserror = { workspace = true }
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tracing = { workspace = true }
crates/smbcloud-deploy/src/build.rs
+250
@@ -76,3 +76,253 @@ impl BuildStrategy for ViteSpaBuild {
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})
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}
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}
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+
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+/// Which SvelteKit adapter a project declares in its `package.json`.
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+#[derive(Debug, Clone, PartialEq, Eq)]
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+pub enum SvelteKitAdapter {
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+ /// `@sveltejs/adapter-static`: prerendered pages plus an optional SPA
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+ /// fallback, served as plain files by nginx.
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+ Static,
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+ /// Any other `@sveltejs/adapter-*` package, e.g. `adapter-node` or
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+ /// `adapter-auto`.
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+ Other(String),
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+ /// `@sveltejs/kit` is present but no adapter package is.
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+ Missing,
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+}
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+
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+impl SvelteKitAdapter {
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+ /// Reads the adapter from `package.json` contents. Returns `None` when the
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+ /// manifest doesn't depend on `@sveltejs/kit` at all.
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+ pub fn from_package_json(contents: &str) -> Result<Option<Self>, serde_json::Error> {
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+ let manifest: serde_json::Value = serde_json::from_str(contents)?;
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+ let dependency_names: Vec<&str> = ["dependencies", "devDependencies"]
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+ .iter()
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+ .filter_map(|section| manifest.get(section).and_then(|value| value.as_object()))
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+ .flat_map(|section| section.keys().map(String::as_str))
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+ .collect();
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+
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+ if !dependency_names.contains(&"@sveltejs/kit") {
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+ return Ok(None);
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+ }
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+
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+ let adapters: Vec<&str> = dependency_names
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+ .iter()
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+ .copied()
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+ .filter(|name| name.starts_with("@sveltejs/adapter-"))
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+ .collect();
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+
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+ // A project can list several adapters (e.g. one per target); static
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+ // wins because it's the only one this strategy can ship.
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+ if adapters.contains(&"@sveltejs/adapter-static") {
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+ return Ok(Some(SvelteKitAdapter::Static));
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+ }
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+ Ok(Some(match adapters.first() {
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+ Some(name) => SvelteKitAdapter::Other((*name).to_string()),
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+ None => SvelteKitAdapter::Missing,
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+ }))
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+ }
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+}
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+
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+/// A SvelteKit build using `@sveltejs/adapter-static`: install dependencies,
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+/// run `<package_manager> run build`, and ship the adapter's output directory
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+/// (`build` by default).
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+///
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+/// Server-rendered adapters are rejected up front. Their output needs a Node
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+/// process on the server, which this static path doesn't manage.
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+pub struct SvelteKitBuild {
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+ pub project_path: String,
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+ pub output_dir: String,
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+ pub package_manager: String,
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+}
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+
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+impl SvelteKitBuild {
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+ fn fail(&self, reporter: &dyn Reporter, message: String) -> DeployError {
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+ reporter.step_fail(&message);
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+ DeployError::Other(anyhow!(message))
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+ }
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+
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+ fn run(&self, reporter: &dyn Reporter, arguments: &[&str]) -> Result<(), DeployError> {
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+ let display = format!("{} {}", self.package_manager, arguments.join(" "));
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+ // Inherited stdio keeps the child on the user's terminal, so package
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+ // manager prompts (e.g. pnpm's modules purge) can still be answered.
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+ let status = Command::new(&self.package_manager)
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+ .args(arguments)
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+ .current_dir(&self.project_path)
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+ .status()
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+ .map_err(|error| {
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+ self.fail(
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+ reporter,
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+ format!("Failed to spawn '{}': {error}", self.package_manager),
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+ )
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+ })?;
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+ if !status.success() {
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+ return Err(self.fail(reporter, format!("'{display}' exited with status {status}")));
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+ }
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+ Ok(())
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+ }
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+}
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+
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+impl BuildStrategy for SvelteKitBuild {
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+ fn build(&self, reporter: &dyn Reporter) -> Result<BuildArtifact, DeployError> {
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+ reporter.step_start(&format!(
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+ "Building SvelteKit app {} with {}…",
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+ self.project_path, self.package_manager
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+ ));
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+
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+ let project_dir = Path::new(&self.project_path);
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+ if !project_dir.exists() {
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+ return Err(self.fail(
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+ reporter,
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+ format!(
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+ "Project path '{}' does not exist. Check the 'source' field in .smb/config.toml.",
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+ self.project_path
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+ ),
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+ ));
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+ }
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+
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+ let manifest_path = project_dir.join("package.json");
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+ let manifest = std::fs::read_to_string(&manifest_path).map_err(|error| {
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+ self.fail(
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+ reporter,
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+ format!("Could not read {}: {error}", manifest_path.display()),
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+ )
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+ })?;
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+ let adapter = SvelteKitAdapter::from_package_json(&manifest).map_err(|error| {
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+ self.fail(
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+ reporter,
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+ format!("Could not parse {}: {error}", manifest_path.display()),
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+ )
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+ })?;
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+
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+ match adapter {
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+ Some(SvelteKitAdapter::Static) => {}
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+ None => {
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+ return Err(self.fail(
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+ reporter,
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+ format!(
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+ "'{}' does not depend on @sveltejs/kit. For a plain Svelte + Vite app, use kind = \"vite-spa\".",
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+ self.project_path
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+ ),
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+ ))
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+ }
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+ Some(SvelteKitAdapter::Missing) => {
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+ return Err(self.fail(
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+ reporter,
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+ "No SvelteKit adapter found. Add @sveltejs/adapter-static and use it in svelte.config.js.".to_string(),
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+ ))
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+ }
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+ Some(SvelteKitAdapter::Other(name)) => {
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+ return Err(self.fail(
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+ reporter,
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+ format!(
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+ "{name} is not supported yet. smbCloud deploys SvelteKit with @sveltejs/adapter-static; switch svelte.config.js to it."
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+ ),
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+ ))
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+ }
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+ }
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+
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+ self.run(reporter, &["install"])?;
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+ self.run(reporter, &["run", "build"])?;
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+
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+ let source_dir = project_dir.join(&self.output_dir);
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+ if !has_html_entry(&source_dir) {
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+ return Err(self.fail(
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+ reporter,
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+ format!(
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+ "{} has no HTML entry point. Prerender at least one page, or set `fallback` in adapter-static for a single-page app.",
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+ source_dir.display()
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+ ),
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+ ));
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+ }
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+
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+ reporter.step_done("Build complete.");
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+ Ok(BuildArtifact { source_dir })
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+ }
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+}
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+
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+/// Whether `directory` holds at least one top-level `.html` file: a
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+/// prerendered `index.html` or an adapter-static fallback such as `200.html`.
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+fn has_html_entry(directory: &Path) -> bool {
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+ let Ok(entries) = std::fs::read_dir(directory) else {
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+ return false;
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+ };
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+ entries.flatten().any(|entry| {
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+ let path: PathBuf = entry.path();
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+ path.is_file()
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+ && path
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+ .extension()
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+ .is_some_and(|extension| extension == "html")
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+ })
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+}
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+
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+#[cfg(test)]
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+mod tests {
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+ use super::*;
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+
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+ #[test]
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+ fn detects_static_adapter_in_dev_dependencies() {
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+ let manifest =
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+ r#"{"devDependencies":{"@sveltejs/kit":"^2","@sveltejs/adapter-static":"^3"}}"#;
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+ assert_eq!(
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+ SvelteKitAdapter::from_package_json(manifest).unwrap(),
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+ Some(SvelteKitAdapter::Static)
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+ );
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+ }
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+
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+ #[test]
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+ fn prefers_static_when_several_adapters_are_listed() {
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+ let manifest = r#"{"dependencies":{"@sveltejs/adapter-node":"^5"},"devDependencies":{"@sveltejs/kit":"^2","@sveltejs/adapter-static":"^3"}}"#;
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+ assert_eq!(
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+ SvelteKitAdapter::from_package_json(manifest).unwrap(),
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+ Some(SvelteKitAdapter::Static)
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+ );
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+ }
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+
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+ #[test]
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+ fn reports_other_adapters_by_name() {
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+ let manifest =
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+ r#"{"devDependencies":{"@sveltejs/kit":"^2","@sveltejs/adapter-auto":"^3"}}"#;
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+ assert_eq!(
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+ SvelteKitAdapter::from_package_json(manifest).unwrap(),
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+ Some(SvelteKitAdapter::Other(
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+ "@sveltejs/adapter-auto".to_string()
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+ ))
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+ );
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+ }
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+
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+ #[test]
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+ fn reports_missing_adapter() {
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+ let manifest = r#"{"devDependencies":{"@sveltejs/kit":"^2"}}"#;
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+ assert_eq!(
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+ SvelteKitAdapter::from_package_json(manifest).unwrap(),
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+ Some(SvelteKitAdapter::Missing)
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+ );
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+ }
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+
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+ #[test]
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+ fn plain_svelte_is_not_sveltekit() {
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+ let manifest = r#"{"devDependencies":{"svelte":"^5","vite":"^5"}}"#;
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+ assert_eq!(SvelteKitAdapter::from_package_json(manifest).unwrap(), None);
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+ }
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+
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+ #[test]
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+ fn invalid_manifest_is_an_error() {
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+ assert!(SvelteKitAdapter::from_package_json("{").is_err());
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+ }
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+
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+ #[test]
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+ fn html_entry_accepts_spa_fallback() {
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+ let directory = tempfile::tempdir().unwrap();
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+ std::fs::write(directory.path().join("200.html"), "<html></html>").unwrap();
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+ assert!(has_html_entry(directory.path()));
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+ }
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+
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+ #[test]
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+ fn html_entry_rejects_missing_or_asset_only_output() {
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+ let directory = tempfile::tempdir().unwrap();
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+ assert!(!has_html_entry(&directory.path().join("build")));
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+ std::fs::create_dir(directory.path().join("_app")).unwrap();
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+ std::fs::write(directory.path().join("robots.txt"), "").unwrap();
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+ assert!(!has_html_entry(directory.path()));
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+ }
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+}
crates/smbcloud-deploy/src/lib.rs
+1
-1
@@ -22,7 +22,7 @@ pub mod report;
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pub mod runner;
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pub mod transport;
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-pub use build::{BuildArtifact, BuildStrategy, ViteSpaBuild};
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+pub use build::{BuildArtifact, BuildStrategy, SvelteKitAdapter, SvelteKitBuild, ViteSpaBuild};
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pub use error::DeployError;
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pub use report::{NoopReporter, Reporter};
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pub use runner::detect_runner;