Fix overly eager replacement of file extensions in uris

As the filename extensions given by the render plugins are also used as
regex for replacing them with .html to generate URIs, the dot in front of
the extension was interpreted as an arbitrary character for the regex.
Also, it matched in the middle of a string. Now dots get quoted and a $
added to only match at the end of the filename.

Fix #16

src/cryogen_core/compiler.clj

@@ -23,6 +23,11 @@
   (if-let [root (k config)]
     (str "/" root "/") "/"))
 
+(defn re-pattern-from-ext
+  "Creates a properly quoted regex pattern for the given file extension"
+  [ext]
+  (re-pattern (str (s/replace ext "." "\\.") "$")))
+
 (defn find-md-assets
   "Returns a list of files ending with .md under templates"
   [ignored-files]
@@ -47,12 +52,12 @@
 (defn post-uri
   "Creates a post uri from the post file name"
   [file-name {:keys [blog-prefix post-root]} mu]
-  (str blog-prefix post-root (s/replace file-name (re-pattern (m/ext mu)) ".html")))
+  (str blog-prefix post-root (s/replace file-name (re-pattern-from-ext (m/ext mu)) ".html")))
 
 (defn page-uri
   "Creates a page uri from the page file name"
   [page-name {:keys [blog-prefix page-root]} mu]
-  (str blog-prefix page-root (s/replace page-name (re-pattern (m/ext mu)) ".html")))
+  (str blog-prefix page-root (s/replace page-name (re-pattern-from-ext (m/ext mu)) ".html")))
 
 (defn read-page-meta
   "Returns the clojure map from the top of a markdown page/post"
@@ -68,7 +73,7 @@
   [page config markup]
   (with-open [rdr (java.io.PushbackReader. (reader page))]
     (let [page-name (.getName page)
-          file-name (s/replace page-name (re-pattern (m/ext markup)) ".html")
+          file-name (s/replace page-name (re-pattern-from-ext (m/ext markup)) ".html")
           page-meta (read-page-meta page-name rdr)
           content ((m/render-fn markup) rdr config)]
       {:file-name file-name