From f11121b0954f9b2eb66d968ea3f0282318e73b12 Mon Sep 17 00:00:00 2001
From: Ryan Levick <ryan.levick@gmail.com>
Date: Thu, 22 Feb 2018 12:01:38 +0100
Subject: [PATCH] Generate enum js code

---
 crates/wasm-bindgen-cli-support/src/js.rs | 16 +++++++++++
 crates/wasm-bindgen-macro/src/ast.rs      | 34 ++++++++++++++++++-----
 crates/wasm-bindgen-shared/src/lib.rs     | 12 ++++++++
 3 files changed, 55 insertions(+), 7 deletions(-)

diff --git a/crates/wasm-bindgen-cli-support/src/js.rs b/crates/wasm-bindgen-cli-support/src/js.rs
index 37ec69fc..56a82442 100644
--- a/crates/wasm-bindgen-cli-support/src/js.rs
+++ b/crates/wasm-bindgen-cli-support/src/js.rs
@@ -978,6 +978,9 @@ impl<'a, 'b> SubContext<'a, 'b> {
         for f in self.program.imports.iter() {
             self.generate_import(f);
         }
+        for e in self.program.enums.iter() {
+            self.generate_enum(e);
+        }
     }
 
     pub fn generate_export(&mut self, export: &shared::Export) {
@@ -1424,6 +1427,19 @@ impl<'a, 'b> SubContext<'a, 'b> {
         self.cx.globals.push_str(&dst);
         self.cx.globals.push_str("\n");
     }
+
+    pub fn generate_enum(&mut self, enum_: &shared::Enum) {
+        let mut variants = String::new();
+
+        let mut value = 0;
+        for variant in enum_.variants.iter() {
+            variants.push_str(&format!("{}:{},", variant.name, value));
+            value = value + 1;
+        }
+        self.cx.globals.push_str(&format!("export const {} = {{", enum_.name));
+        self.cx.globals.push_str(&variants);
+        self.cx.globals.push_str("}\n");
+    }
 }
 
 struct VectorType {
diff --git a/crates/wasm-bindgen-macro/src/ast.rs b/crates/wasm-bindgen-macro/src/ast.rs
index 2904ed0c..5b75e647 100644
--- a/crates/wasm-bindgen-macro/src/ast.rs
+++ b/crates/wasm-bindgen-macro/src/ast.rs
@@ -327,17 +327,24 @@ impl Program {
             a.fields(&[
                 ("exports", &|a| a.list(&self.exports, Export::wbg_literal)),
                 ("imports", &|a| a.list(&self.imports, Import::wbg_literal)),
+                ("enums", &|a| a.list(&self.enums, Enum::wbg_literal)),
                 ("custom_type_names", &|a| {
-                    let names = self.exports.iter()
+                    let struct_descriptors = self.exports.iter()
                         .filter_map(|e| e.class)
                         .chain(self.structs.iter().map(|s| s.name))
-                        .chain(self.enums.iter().map(|s| s.name))
-                        .collect::<BTreeSet<_>>();
-                    a.list(&names, |s, a| {
-                        let val = shared::name_to_descriptor(s.as_ref());
+                        .map(|n| {
+                            let val = shared::name_to_descriptor(n.as_ref());
+                            (val, n.to_string())
+                        });
+                    let enum_descriptors = self.enums.iter().map(|e| {
+                            (shared::TYPE_ENUM, e.name.to_string())
+                        });
+                    let descriptors = struct_descriptors.chain(enum_descriptors).collect::<BTreeSet<_>>();
+
+                    a.list(&descriptors, |s, a| {
                         a.fields(&[
-                            ("descriptor", &|a| a.char(val)),
-                            ("name", &|a| a.str(s.as_ref()))
+                            ("descriptor", &|a| a.char(s.0)),
+                            ("name", &|a| a.str(&s.1))
                         ]);
                     })
                 }),
@@ -665,6 +672,19 @@ impl Import {
     }
 }
 
+impl Enum {
+    fn wbg_literal(&self, a: &mut LiteralBuilder) {
+        a.fields(&[
+                 ("name", &|a| a.str(self.name.as_ref())),
+                 ("variants", &|a| a.list(&self.variants, |v, a| {
+                     a.fields(&[
+                              ("name", &|a| a.str(v.as_ref()))
+                     ])
+                 })),
+        ]);
+    }
+}
+
 impl Struct {
     fn from(s: syn::ItemStruct, _opts: BindgenAttrs) -> Struct {
         Struct { name: s.ident }
diff --git a/crates/wasm-bindgen-shared/src/lib.rs b/crates/wasm-bindgen-shared/src/lib.rs
index 2047ce99..7d85eeeb 100644
--- a/crates/wasm-bindgen-shared/src/lib.rs
+++ b/crates/wasm-bindgen-shared/src/lib.rs
@@ -8,6 +8,7 @@ use std::hash::{Hash, Hasher};
 #[derive(Deserialize)]
 pub struct Program {
     pub exports: Vec<Export>,
+    pub enums: Vec<Enum>,
     pub imports: Vec<Import>,
     pub custom_type_names: Vec<CustomTypeName>,
 }
@@ -32,6 +33,17 @@ pub struct Export {
     pub function: Function,
 }
 
+#[derive(Deserialize)]
+pub struct Enum {
+    pub name: String,
+    pub variants: Vec<EnumVariant>,
+}
+
+#[derive(Deserialize)]
+pub struct EnumVariant {
+    pub name: String
+}
+
 #[derive(Deserialize)]
 pub struct Function {
     pub name: String,