chore: use static params when dynamic param metadata is missing (#17836)

Existing template versions do not have the metadata (modules + plan) in
the db. So revert to using static parameter information from the
original template import.

This data will still be served over the websocket.

coderd/files/cache.go

@@ -16,7 +16,7 @@ import (
 
 // NewFromStore returns a file cache that will fetch files from the provided
 // database.
-func NewFromStore(store database.Store) Cache {
+func NewFromStore(store database.Store) *Cache {
 	fetcher := func(ctx context.Context, fileID uuid.UUID) (fs.FS, error) {
 		file, err := store.GetFileByID(ctx, fileID)
 		if err != nil {
@@ -27,7 +27,7 @@ func NewFromStore(store database.Store) Cache {
 		return archivefs.FromTarReader(content), nil
 	}
 
-	return Cache{
+	return &Cache{
 		lock:    sync.Mutex{},
 		data:    make(map[uuid.UUID]*cacheEntry),
 		fetcher: fetcher,
@@ -112,3 +112,12 @@ func (c *Cache) Release(fileID uuid.UUID) {
 
 	delete(c.data, fileID)
 }
+
+// Count returns the number of files currently in the cache.
+// Mainly used for unit testing assertions.
+func (c *Cache) Count() int {
+	c.lock.Lock()
+	defer c.lock.Unlock()
+
+	return len(c.data)
+}