Fix generating URLs for index documents

Changelog: fixed

src/wobsite.inko

@@ -17,6 +17,8 @@ import wobsite.fnmatch
 import wobsite.time.(parse_date)
 import wobsite.url.(file_url)
 
+let INDEX_FILE = 'index.md'
+
 # A type that maps asset paths/URIs to their checksums/hashes.
 class Hashes {
   # The keys of this map start with a `/`, such that relative URLs such as
@@ -605,7 +607,7 @@ class async Worker {
   ) {
     let source = recover source
     let rel_source = source.strip_prefix(@files.source).unwrap
-    let target = if rel_source.tail == 'index.md' {
+    let target = if rel_source.tail == INDEX_FILE {
       @files.output.join(rel_source.with_extension('html'))
     } else {
       @files.output.join(rel_source.with_extension('').join('index.html'))

src/wobsite/url.inko

@@ -1,4 +1,5 @@
 import std.fs.path.Path
+import wobsite.INDEX_FILE
 
 let TAB = 9
 let LF = 10
@@ -67,11 +68,13 @@ fn pub normalize(string: String) -> String {
 
 # Returns the relative URL for a file path in a directory.
 fn pub file_url(directory: ref Path, path: ref Path) -> String {
-  let rel = path
-    .strip_prefix(directory)
-    .unwrap_or_else fn { path.clone }
-    .with_extension('')
-    .to_string
+  let rel = path.strip_prefix(directory).unwrap_or_else fn { path.clone }
 
-  if rel == 'index' { '/' } else { "/{rel}/" }
+  if rel.to_string == INDEX_FILE {
+    '/'
+  } else if rel.tail == INDEX_FILE {
+    "/{rel.directory.with_extension('')}/"
+  } else {
+    "/{rel.with_extension('')}/"
+  }
 }

test/wobsite/test_url.inko

@@ -21,7 +21,16 @@ fn pub tests(t: mut Tests) {
       '/bar/foo/bar/'
     )
 
+    t.equal(
+      url.file_url(Path.new('source'), Path.new('bar/foo/index.md')),
+      '/bar/foo/'
+    )
+
     t.equal(url.file_url(Path.new('source'), Path.new('source/index.md')), '/')
     t.equal(url.file_url(Path.new('source'), Path.new('index.md')), '/')
+    t.equal(
+      url.file_url(Path.new('source'), Path.new('source/foo/index.md')),
+      '/foo/'
+    )
   }
 }