start working on migrations

2 files changed, 32 insertions, 1 deletions

diff --git a/tosin-macros/Cargo.toml b/tosin-macros/Cargo.toml
index 4a58a20..836461c 100644
--- a/tosin-macros/Cargo.toml
+++ b/tosin-macros/Cargo.toml
@@ -10,5 +10,5 @@ edition = "2018"
 proc-macro = true
 
 [dependencies]
-syn = "1.0"
+syn = { version = "1.0", features = ["full", "extra-traits"] }
 quote = "1.0"
diff --git a/tosin-macros/src/lib.rs b/tosin-macros/src/lib.rs
index c0651fa..7efbac6 100644
--- a/tosin-macros/src/lib.rs
+++ b/tosin-macros/src/lib.rs
@@ -1,3 +1,5 @@
+#![feature(proc_macro_span)]
+
 extern crate proc_macro;
 
 use proc_macro::TokenStream;
@@ -24,3 +26,32 @@ fn impl_model(ast: &syn::DeriveInput) -> TokenStream {
     };
     gen.into()
 }
+
+#[proc_macro]
+pub fn gather_migrations(_input: TokenStream) -> TokenStream {
+    let call_site = proc_macro::Span::call_site();
+    let call_site_file = call_site.source_file();
+    let call_site_path = call_site_file.path();
+    if !call_site_file.is_real() {
+        panic!("call site does not have a real path");
+    }
+
+    let migrations_dir = call_site_path.parent().unwrap();
+    let migrations: Vec<syn::Ident> = migrations_dir.read_dir()
+        .unwrap()
+        .map(Result::unwrap)
+        .map(|x| x.path().file_stem().unwrap().to_string_lossy().into_owned())
+        .filter(|x| x != "mod")
+        .map(|x| syn::parse_str(&x).unwrap())
+        .collect();
+
+    let gen = quote! {
+        #( mod #migrations; )*
+
+        pub const migrations: &[Migration] = &[
+            #(#migrations::MIGRATION),*
+        ];
+    };
+
+    gen.into()
+}