Ensure root output directory exists explicitly.

Aliases that have no directory nesting sneakily avoid the code path that ensures the directories exist

components/site/src/lib.rs

@@ -565,6 +565,7 @@ impl Site {
     }
 
     pub fn render_aliases(&self) -> Result<()> {
+        ensure_directory_exists(&self.output_path)?;
         for (_, page) in self.library.pages() {
             for alias in &page.meta.aliases {
                 let mut output_path = self.output_path.to_path_buf();

components/site/tests/site.rs

@@ -19,7 +19,7 @@ fn can_parse_site() {
     site.load().unwrap();
 
     // Correct number of pages (sections are pages too)
-    assert_eq!(site.library.pages().len(), 15);
+    assert_eq!(site.library.pages().len(), 16);
     let posts_path = path.join("content").join("posts");
 
     // Make sure the page with a url doesn't have any sections
@@ -41,7 +41,7 @@ fn can_parse_site() {
 
     let posts_section = site.library.get_section(&posts_path.join("_index.md")).unwrap();
     assert_eq!(posts_section.subsections.len(), 1);
-    assert_eq!(posts_section.pages.len(), 7);
+    assert_eq!(posts_section.pages.len(), 8);
     assert_eq!(posts_section.ancestors, vec![*site.library.get_section_key(&index_section.file.path).unwrap()]);
 
     // Make sure we remove all the pwd + content from the sections

test_site/content/posts/top-level-alias.md

@@ -0,0 +1,8 @@
++++
+title = "Top level alias"
+description = ""
+date = 2017-01-01
+aliases = ["top-level.html"]
++++
+
+Simple page