feat: support semver aware WIT

Signed-off-by: Victor Adossi <vadossi@cosmonic.com>

Cargo.toml

@@ -37,6 +37,8 @@ strip = true
 anyhow = "1.0.86"
 base64 = "0.22.1"
 heck = "0.5.0"
+log = "0.4.22"
+semver = "1.0.23"
 js-component-bindgen = { path = "./crates/js-component-bindgen" }
 structopt = "0.3.26"
 wasm-encoder = "0.212.0"
@@ -55,4 +57,4 @@ wit-parser = "0.212.0"
 xshell = "0.2.6"
 
 [dev-dependencies]
-anyhow = { workspace = true }
+anyhow = { workspace = true }

crates/js-component-bindgen-component/src/lib.rs

@@ -113,6 +113,20 @@ impl Guest for JsComponentBindgenComponent {
         opts: TypeGenerationOptions,
     ) -> Result<Vec<(String, Vec<u8>)>, String> {
         let mut resolve = Resolve::default();
+
+        // Add features if specified
+        match opts.features {
+            Some(EnabledFeatureSet::List(ref features)) => {
+                for f in features.into_iter() {
+                    resolve.features.insert(f.to_string());
+                }
+            }
+            Some(EnabledFeatureSet::All) => {
+                resolve.all_features = true;
+            }
+            _ => {}
+        }
+
         let ids = match opts.wit {
             Wit::Source(source) => resolve
                 .push_str(format!("{name}.wit"), &source)

crates/js-component-bindgen-component/wit/js-component-bindgen.wit

@@ -73,6 +73,14 @@ world js-component-bindgen {
     path(string),
   }
 
+  /// Enumerate enabled features
+  variant enabled-feature-set {
+    /// Enable only the given list of features
+    %list(list<string>),
+    /// Enable all features
+    all,
+  }
+
   record type-generation-options {
     /// wit to generate typing from
     wit: wit,
@@ -81,6 +89,8 @@ world js-component-bindgen {
     tla-compat: option<bool>,
     instantiation: option<instantiation-mode>,
     map: option<maps>,
+    /// Features that should be enabled as part of feature gating
+    features: option<enabled-feature-set>,
   }
 
   enum export-type {

crates/js-component-bindgen/Cargo.toml

@@ -22,11 +22,13 @@ transpile-bindgen = []
 
 [dependencies]
 anyhow = { workspace = true }
+base64 = { workspace = true }
 heck = { workspace = true }
+log = { workspace = true }
+semver = { workspace = true }
+wasm-encoder = { workspace = true }
 wasmparser = { workspace = true }
 wasmtime-environ = { workspace = true, features = ['component-model'] }
 wit-bindgen-core = { workspace = true }
 wit-component = { workspace = true }
 wit-parser = { workspace = true }
-base64 = { workspace = true }
-wasm-encoder = { workspace = true }

crates/js-component-bindgen/src/lib.rs

@@ -13,14 +13,14 @@ pub use transpile_bindgen::{BindingsMode, InstantiationMode, TranspileOpts};
 use anyhow::Result;
 use transpile_bindgen::transpile_bindgen;
 
-use anyhow::{bail, Context};
+use anyhow::{bail, ensure, Context};
 use wasmtime_environ::component::{ComponentTypesBuilder, Export, StaticModuleIndex};
 use wasmtime_environ::wasmparser::Validator;
 use wasmtime_environ::{PrimaryMap, ScopeVec, Tunables};
 use wit_component::DecodedWasm;
 
 use ts_bindgen::ts_bindgen;
-use wit_parser::{Resolve, Type, TypeDefKind, TypeId, WorldId};
+use wit_parser::{Package, Resolve, Stability, Type, TypeDefKind, TypeId, WorldId};
 
 /// Calls [`write!`] with the passed arguments and unwraps the result.
 ///
@@ -172,3 +172,35 @@ pub fn dealias(resolve: &Resolve, mut id: TypeId) -> TypeId {
         }
     }
 }
+
+/// Check if an item (usually some form of [`WorldItem`]) should be allowed through the feature gate
+/// of a given package.
+fn feature_gate_allowed(
+    resolve: &Resolve,
+    package: &Package,
+    stability: &Stability,
+) -> Result<bool> {
+    Ok(match stability {
+        Stability::Unknown => true,
+        Stability::Stable { since, .. } => {
+            let Some(package_version) = package.name.version.as_ref() else {
+                // If the package version is missing (we're likely dealing with an unresolved package)
+                // and we can't really check much.
+                return Ok(true);
+            };
+
+            ensure!(
+                package_version >= since,
+                "feature gates cannot refer to unreleased (future) package versions"
+            );
+
+            // Stabilization (@since annotation) overrides features and deprecation
+            true
+        }
+        Stability::Unstable { feature } => {
+            // If a @unstable feature is present but the related feature was not enabled
+            // or all features was not selected, exclude
+            resolve.all_features || resolve.features.contains(feature)
+        }
+    })
+}

crates/js-component-bindgen/src/ts_bindgen.rs

@@ -3,12 +3,16 @@ use crate::function_bindgen::{array_ty, as_nullable, maybe_null};
 use crate::names::{is_js_identifier, maybe_quote_id, LocalNames, RESERVED_KEYWORDS};
 use crate::source::Source;
 use crate::transpile_bindgen::{parse_world_key, InstantiationMode, TranspileOpts};
-use crate::{dealias, uwrite, uwriteln};
+use crate::{dealias, feature_gate_allowed, uwrite, uwriteln};
 use heck::*;
+use log::debug;
 use std::collections::btree_map::Entry;
 use std::collections::{BTreeMap, HashSet};
 use std::fmt::Write;
-use wit_parser::*;
+use wit_bindgen_core::wit_parser::{
+    Docs, Enum, Flags, Function, FunctionKind, Handle, InterfaceId, Record, Resolve, Result_,
+    Tuple, Type, TypeDefKind, TypeId, TypeOwner, Variant, WorldId, WorldItem, WorldKey,
+};
 
 struct TsBindgen {
     /// The source code for the "main" file that's going to be created for the
@@ -57,42 +61,76 @@ pub fn ts_bindgen(
     };
 
     let world = &resolve.worlds[id];
+    let package = resolve
+        .packages
+        .get(
+            world
+                .package
+                .expect("unexpectedly missing package in world"),
+        )
+        .expect("unexpectedly missing package in world for ID");
 
     {
         let mut funcs = Vec::new();
         let mut interface_imports = BTreeMap::new();
         for (name, import) in world.imports.iter() {
             match import {
-                WorldItem::Function(f) => match name {
-                    WorldKey::Name(name) => funcs.push((name.to_string(), f)),
-                    WorldKey::Interface(id) => funcs.push((resolve.id_of(*id).unwrap(), f)),
-                },
-                WorldItem::Interface { id, stability: _ } => match name {
-                    WorldKey::Name(name) => {
-                        // kebab name -> direct ns namespace import
-                        bindgen.import_interface(resolve, name, *id, files);
+                WorldItem::Function(f) => {
+                    if !feature_gate_allowed(resolve, package, &f.stability)
+                        .expect("failed to check feature gate for imported function")
+                    {
+                        debug!("skipping imported function [{}] feature gate due to feature gate visibility", f.name);
+                        continue;
                     }
-                    // namespaced ns:pkg/iface
-                    // TODO: map support
-                    WorldKey::Interface(id) => {
+
+                    match name {
+                        WorldKey::Name(name) => funcs.push((name.to_string(), f)),
+                        WorldKey::Interface(id) => funcs.push((resolve.id_of(*id).unwrap(), f)),
+                    }
+                }
+                WorldItem::Interface { id, stability } => {
+                    if !feature_gate_allowed(resolve, package, &stability)
+                        .expect("failed to check feature gate for imported interface")
+                    {
                         let import_specifier = resolve.id_of(*id).unwrap();
                         let (_, _, iface) = parse_world_key(&import_specifier).unwrap();
-                        let iface = iface.to_string();
-                        match interface_imports.entry(import_specifier) {
-                            Entry::Vacant(entry) => {
-                                entry.insert(vec![("*".into(), id)]);
-                            }
-                            Entry::Occupied(ref mut entry) => {
-                                entry.get_mut().push((iface, id));
+                        debug!("skipping imported interface [{}] feature gate due to feature gate visibility", iface.to_string());
+                        continue;
+                    }
+
+                    match name {
+                        WorldKey::Name(name) => {
+                            // kebab name -> direct ns namespace import
+                            bindgen.import_interface(resolve, &name, *id, files);
+                        }
+                        // namespaced ns:pkg/iface
+                        // TODO: map support
+                        WorldKey::Interface(id) => {
+                            let import_specifier = resolve.id_of(*id).unwrap();
+                            let (_, _, iface) = parse_world_key(&import_specifier).unwrap();
+                            let iface = iface.to_string();
+                            match interface_imports.entry(import_specifier) {
+                                Entry::Vacant(entry) => {
+                                    entry.insert(vec![("*".into(), id)]);
+                                }
+                                Entry::Occupied(ref mut entry) => {
+                                    entry.get_mut().push((iface, id));
+                                }
                             }
                         }
                     }
-                },
+                }
                 WorldItem::Type(tid) => {
                     let ty = &resolve.types[*tid];
-
                     let name = ty.name.as_ref().unwrap();
 
+                    if !feature_gate_allowed(resolve, package, &ty.stability)
+                        .expect("failed to check feature gate for imported type")
+                    {
+                        debug!("skipping imported type [{name}] feature gate due to feature gate visibility");
+                        continue;
+                    }
+
                     let mut gen = bindgen.ts_interface(resolve, true);
                     gen.docs(&ty.docs);
                     match &ty.kind {
@@ -134,17 +172,24 @@ pub fn ts_bindgen(
     let mut funcs = Vec::new();
     let mut seen_names = HashSet::new();
     let mut export_aliases: Vec<(String, String)> = Vec::new();
+
     for (name, export) in world.exports.iter() {
         match export {
             WorldItem::Function(f) => {
                 let export_name = match name {
                     WorldKey::Name(export_name) => export_name,
                     WorldKey::Interface(_) => unreachable!(),
                 };
+                if !feature_gate_allowed(resolve, package, &f.stability)
+                    .expect("failed to check feature gate for export")
+                {
+                    debug!("skipping exported interface [{export_name}] feature gate due to feature gate visibility");
+                    continue;
+                }
                 seen_names.insert(export_name.to_string());
                 funcs.push((export_name.to_lower_camel_case(), f));
             }
-            WorldItem::Interface { id, stability: _ } => {
+            WorldItem::Interface { id, stability } => {
                 let iface_id: String;
                 let (export_name, iface_name): (&str, &str) = match name {
                     WorldKey::Name(export_name) => (export_name, export_name),
@@ -154,6 +199,14 @@ pub fn ts_bindgen(
                         (iface_id.as_ref(), iface)
                     }
                 };
+
+                if !feature_gate_allowed(resolve, package, &stability)
+                    .expect("failed to check feature gate for export")
+                {
+                    debug!("skipping exported interface [{export_name}] feature gate due to feature gate visibility");
+                    continue;
+                }
+
                 seen_names.insert(export_name.to_string());
                 let local_name = bindgen.export_interface(
                     resolve,
@@ -414,6 +467,14 @@ impl TsBindgen {
         id: InterfaceId,
         files: &mut Files,
     ) -> String {
+        let iface = resolve
+            .interfaces
+            .get(id)
+            .expect("unexpectedly missing interface in resolve");
+        let package = resolve
+            .packages
+            .get(iface.package.expect("missing package on interface"))
+            .expect("unexpectedly missing package");
         let id_name = resolve.id_of(id).unwrap_or_else(|| name.to_string());
         let goal_name = interface_goal_name(&id_name);
         let goal_name_kebab = goal_name.to_kebab_case();
@@ -456,10 +517,16 @@ impl TsBindgen {
         let mut gen = self.ts_interface(resolve, false);
 
         uwriteln!(gen.src, "export namespace {camel} {{");
-
         for (_, func) in resolve.interfaces[id].functions.iter() {
+            // Ensure that the function  the world item for stability guarantees and exclude if they do not match
+            if !feature_gate_allowed(resolve, package, &func.stability)
+                .expect("failed to check feature gate for function")
+            {
+                continue;
+            }
             gen.ts_func(func, false, true);
         }
+        // Export resources for the interface
         for (_, ty) in resolve.interfaces[id].types.iter() {
             let ty = &resolve.types[*ty];
             if let TypeDefKind::Resource = ty.kind {

crates/wasm-tools-component/src/lib.rs

@@ -7,7 +7,8 @@ use wit_component::{ComponentEncoder, DecodedWasm, WitPrinter};
 use wit_parser::Resolve;
 
 use exports::local::wasm_tools::tools::{
-    EmbedOpts, Guest, ModuleMetaType, ModuleMetadata, ProducersFields, StringEncoding,
+    EmbedOpts, EnabledFeatureSet, Guest, ModuleMetaType, ModuleMetadata, ProducersFields,
+    StringEncoding,
 };
 
 wit_bindgen::generate!({
@@ -74,6 +75,20 @@ impl Guest for WasmToolsJs {
 
         let mut resolve = Resolve::default();
 
+        // Add all features specified in embed options to the resolve
+        // (this helps identify/use feature gating properly)
+        match embed_opts.features {
+            Some(EnabledFeatureSet::List(ref features)) => {
+                for f in features.into_iter() {
+                    resolve.features.insert(f.to_string());
+                }
+            }
+            Some(EnabledFeatureSet::All) => {
+                resolve.all_features = true;
+            }
+            _ => {}
+        };
+
         let ids = if let Some(wit_source) = &embed_opts.wit_source {
             let path = PathBuf::from("component.wit");
             resolve
@@ -89,6 +104,7 @@ impl Guest for WasmToolsJs {
         };
 
         let world_string = embed_opts.world.as_ref().map(|world| world.to_string());
+
         let world = resolve
             .select_world(&ids, world_string.as_deref())
             .map_err(|e| e.to_string())?;