Add test for static fs not creating directory

Signed-off-by: itowlson <[email protected]>

crates/templates/src/lib.rs

@@ -24,3 +24,6 @@ pub use manager::*;
 pub use run::{Run, RunOptions};
 pub use source::TemplateSource;
 pub use template::{Template, TemplateVariantInfo};
+
+#[cfg(test)]
+mod test_built_ins;

crates/templates/src/manager.rs

@@ -107,7 +107,11 @@ impl TemplateManager {
     /// Creates a `TemplateManager` for the default install location.
     pub fn try_default() -> anyhow::Result<Self> {
         let store = TemplateStore::try_default()?;
-        Ok(Self { store })
+        Ok(Self::new(store))
+    }
+
+    pub(crate) fn new(store: TemplateStore) -> Self {
+        Self { store }
     }
 
     /// Installs templates from the specified source.

crates/templates/src/test_built_ins/mod.rs

@@ -0,0 +1,73 @@
+#![cfg(test)]
+
+// Module for unit-testing the built-in templates when a full e2e test would be overkill.
+// If your test involves invoking the Spin CLI, or builds or runs an application, use
+// an e2e test.
+
+use std::{collections::HashMap, path::PathBuf};
+
+use super::*;
+
+struct DiscardingReporter;
+
+impl ProgressReporter for DiscardingReporter {
+    fn report(&self, _: impl AsRef<str>) {}
+}
+
+#[tokio::test]
+async fn add_fileserver_does_not_create_dir() -> anyhow::Result<()> {
+    let built_ins_dir = PathBuf::from(env!("CARGO_MANIFEST_DIR")).join("../..");
+    let built_ins_src = TemplateSource::File(built_ins_dir);
+
+    let store_dir = tempfile::tempdir()?;
+    let store = store::TemplateStore::new(store_dir.path());
+    let manager = TemplateManager::new(store);
+
+    manager
+        .install(
+            &built_ins_src,
+            &InstallOptions::default(),
+            &DiscardingReporter,
+        )
+        .await?;
+
+    let app_dir = tempfile::tempdir()?;
+
+    // Create an app to add the fileserver into
+    let new_empty_options = RunOptions {
+        variant: TemplateVariantInfo::NewApplication,
+        name: "add-fs-dir-test".to_owned(),
+        output_path: app_dir.path().to_owned(),
+        values: HashMap::new(),
+        accept_defaults: true,
+    };
+    manager
+        .get("http-empty")?
+        .expect("http-empty template should exist")
+        .run(new_empty_options)
+        .silent()
+        .await?;
+
+    // Add the fileserver to that app
+    let manifest_path = app_dir.path().join("spin.toml");
+    let add_fs_options = RunOptions {
+        variant: TemplateVariantInfo::AddComponent { manifest_path },
+        name: "fs".to_owned(),
+        output_path: app_dir.path().join("fs"),
+        values: HashMap::new(),
+        accept_defaults: true,
+    };
+    manager
+        .get("static-fileserver")?
+        .expect("static-fileserver template should exist")
+        .run(add_fs_options)
+        .silent()
+        .await?;
+
+    // Finally!
+    assert!(
+        !app_dir.path().join("fs").exists(),
+        "<app_dir>/fs should not have been created"
+    );
+    Ok(())
+}