diff --git a/libs/codegen/src/lib.rs b/libs/codegen/src/lib.rs
index 6055b93..4c708d5 100644
--- a/libs/codegen/src/lib.rs
+++ b/libs/codegen/src/lib.rs
@@ -8,104 +8,10 @@ extern crate sha2;
 extern crate syn;
 
 use proc_macro::TokenStream;
-use std::fs::File;
-use std::io::prelude::*;
-use std::path::{Path, PathBuf};
 
-fn user_crate_root() -> PathBuf {
-    std::env::current_dir().expect("Unable to get current directory")
-}
-
-fn find_attr<'a>(attrs: &'a Vec<syn::Attribute>, name: &str) -> Option<&'a str> {
-    attrs.iter()
-        .find(|&x| x.name() == name)
-        .and_then(|ref attr| match &attr.value {
-            &syn::MetaItem::NameValue(_, syn::Lit::Str(ref template, _)) => Some(template),
-            _ => None
-        })
-        .map(|x| x.as_ref())
-}
-
-fn buf_file<P: AsRef<Path>>(filename: P) -> Vec<u8> {
-    let mut f = File::open(filename)
-        .expect("Unable to open file for reading");
-
-    let mut buf = Vec::new();
-    f.read_to_end(&mut buf)
-        .expect("Unable to read file");
-
-    buf
-}
-
-fn calculate_checksum<P: AsRef<Path>>(filename: P) -> String {
-    use base64::*;
-    use sha2::{Sha256, Digest};
-
-    encode_config(&Sha256::digest(&buf_file(filename)), URL_SAFE)
-}
+mod static_resource;
 
 #[proc_macro_derive(StaticResource, attributes(filename, mime))]
 pub fn static_resource(input: TokenStream) -> TokenStream {
-    let s = input.to_string();
-    let ast = syn::parse_macro_input(&s).unwrap();
-
-    let filename = find_attr(&ast.attrs, "filename")
-        .expect("The `filename` attribute must be specified");
-    let abs_filename = user_crate_root().join(filename);
-    let abs_filename = abs_filename.to_str().expect("Absolute file path must be valid Unicode");
-
-    let checksum = calculate_checksum(&abs_filename);
-
-    let mime = find_attr(&ast.attrs, "mime")
-        .expect("The `mime` attribute must be specified");
-
-    let name = &ast.ident;
-    let (impl_generics, ty_generics, where_clause) = ast.generics.split_for_impl();
-
-    let gen = quote! {
-        #[allow(unused_attributes, unused_qualifications, unknown_lints, clippy)]
-        #[automatically_derived]
-        impl #impl_generics Resource for #name #ty_generics #where_clause {
-            fn allow(&self) -> Vec<::hyper::Method> {
-                use ::hyper::Method::*;
-                vec![Options, Head, Get]
-            }
-
-            fn head(&self) -> ResponseFuture {
-                Box::new(::futures::finished(::hyper::server::Response::new()
-                    .with_status(::hyper::StatusCode::Ok)
-                    .with_header(::hyper::header::ContentType(
-                        #mime.parse().expect("Statically supplied mime type must be parseable")))
-                    .with_header(::hyper::header::CacheControl(vec![
-                        ::hyper::header::CacheDirective::Extension("immutable".to_owned(), None),
-                        ::hyper::header::CacheDirective::MaxAge(31556926),
-                        ::hyper::header::CacheDirective::Public,
-                    ]))
-                    .with_header(::hyper::header::ETag(Self::etag()))
-                ))
-            }
-
-            fn get(self: Box<Self>) -> ResponseFuture {
-                let body = include_bytes!(#abs_filename);
-
-                Box::new(self.head().map(move |head|
-                    head
-                        .with_header(::hyper::header::ContentLength(body.len() as u64))
-                        .with_body(body as &'static [u8])
-                ))
-            }
-        }
-
-        impl #impl_generics #name #ty_generics #where_clause {
-            pub fn checksum() -> &'static str {
-                #checksum
-            }
-
-            pub fn etag() -> ::hyper::header::EntityTag {
-                ::hyper::header::EntityTag::new(false, Self::checksum().to_owned())
-            }
-        }
-    };
-
-    gen.parse().unwrap()
+    static_resource::static_resource(input)
 }
diff --git a/libs/codegen/src/static_resource.rs b/libs/codegen/src/static_resource.rs
new file mode 100644
index 0000000..a7d85e9
--- /dev/null
+++ b/libs/codegen/src/static_resource.rs
@@ -0,0 +1,104 @@
+use std;
+use std::fs::File;
+use std::io::prelude::*;
+use std::path::{Path, PathBuf};
+
+use proc_macro::TokenStream;
+use syn;
+
+fn user_crate_root() -> PathBuf {
+    std::env::current_dir().expect("Unable to get current directory")
+}
+
+fn find_attr<'a>(attrs: &'a Vec<syn::Attribute>, name: &str) -> Option<&'a str> {
+    attrs.iter()
+        .find(|&x| x.name() == name)
+        .and_then(|ref attr| match &attr.value {
+            &syn::MetaItem::NameValue(_, syn::Lit::Str(ref template, _)) => Some(template),
+            _ => None
+        })
+        .map(|x| x.as_ref())
+}
+
+fn buf_file<P: AsRef<Path>>(filename: P) -> Vec<u8> {
+    let mut f = File::open(filename)
+        .expect("Unable to open file for reading");
+
+    let mut buf = Vec::new();
+    f.read_to_end(&mut buf)
+        .expect("Unable to read file");
+
+    buf
+}
+
+fn calculate_checksum<P: AsRef<Path>>(filename: P) -> String {
+    use base64::*;
+    use sha2::{Sha256, Digest};
+
+    encode_config(&Sha256::digest(&buf_file(filename)), URL_SAFE)
+}
+
+pub fn static_resource(input: TokenStream) -> TokenStream {
+    let s = input.to_string();
+    let ast = syn::parse_macro_input(&s).unwrap();
+
+    let filename = find_attr(&ast.attrs, "filename")
+        .expect("The `filename` attribute must be specified");
+    let abs_filename = user_crate_root().join(filename);
+    let abs_filename = abs_filename.to_str().expect("Absolute file path must be valid Unicode");
+
+    let checksum = calculate_checksum(&abs_filename);
+
+    let mime = find_attr(&ast.attrs, "mime")
+        .expect("The `mime` attribute must be specified");
+
+    let name = &ast.ident;
+    let (impl_generics, ty_generics, where_clause) = ast.generics.split_for_impl();
+
+    let gen = quote! {
+        #[allow(unused_attributes, unused_qualifications, unknown_lints, clippy)]
+        #[automatically_derived]
+        impl #impl_generics Resource for #name #ty_generics #where_clause {
+            fn allow(&self) -> Vec<::hyper::Method> {
+                use ::hyper::Method::*;
+                vec![Options, Head, Get]
+            }
+
+            fn head(&self) -> ResponseFuture {
+                Box::new(::futures::finished(::hyper::server::Response::new()
+                    .with_status(::hyper::StatusCode::Ok)
+                    .with_header(::hyper::header::ContentType(
+                        #mime.parse().expect("Statically supplied mime type must be parseable")))
+                    .with_header(::hyper::header::CacheControl(vec![
+                        ::hyper::header::CacheDirective::Extension("immutable".to_owned(), None),
+                        ::hyper::header::CacheDirective::MaxAge(31556926),
+                        ::hyper::header::CacheDirective::Public,
+                    ]))
+                    .with_header(::hyper::header::ETag(Self::etag()))
+                ))
+            }
+
+            fn get(self: Box<Self>) -> ResponseFuture {
+                let body = include_bytes!(#abs_filename);
+
+                Box::new(self.head().map(move |head|
+                    head
+                        .with_header(::hyper::header::ContentLength(body.len() as u64))
+                        .with_body(body as &'static [u8])
+                ))
+            }
+        }
+
+        impl #impl_generics #name #ty_generics #where_clause {
+            pub fn checksum() -> &'static str {
+                #checksum
+            }
+
+            pub fn etag() -> ::hyper::header::EntityTag {
+                ::hyper::header::EntityTag::new(false, Self::checksum().to_owned())
+            }
+        }
+    };
+
+    gen.parse().unwrap()
+}