TINYGO + WASI + wash build = YES PLEASE

Cargo.toml

@@ -150,11 +150,14 @@ toml = "0.7.8"
 wadm = "0.6.0"
 walkdir = "2.4"
 wascap = "0.11.2"
+wasm-encoder = "0.33.2"
 wash-lib = { version = "0.11", path = "./crates/wash-lib" }
-wasmbus-rpc = "0.14.0"
+wasmbus-rpc = "0.14"
 wasmcloud-component-adapters = { version = "0.2.4" }
 wasmcloud-control-interface = "0.27"
 wasmcloud-test-util = "0.10.0"
 weld-codegen = "0.7.0"
 which = "4.4.0"
-wit-component = "0.13.2"
+wit-component = "0.14.4"
+wit-parser = "0.11.3"
+wat = "1.0.74"

crates/wash-lib/Cargo.toml

@@ -60,9 +60,9 @@ reqwest = { workspace = true, features = ["json", "rustls-tls", "stream"] }
 rmp-serde = "1"
 semver = { workspace = true, features = ["serde"], optional = true }
 serde = { workspace = true, features = ["derive"], optional = true }
+serde-transcode = "1"
 serde_cbor = "0.11"
 serde_json = { workspace = true, optional = true }
-serde-transcode = "1"
 serde_with = { workspace = true }
 tempfile = { workspace = true }
 term-table = { workspace = true, optional = true }
@@ -76,11 +76,14 @@ toml = { workspace = true }
 wadm = { workspace = true, optional = true }
 walkdir = { workspace = true }
 wascap = { workspace = true }
+wasm-encoder = { workspace = true }
+wasmbus-rpc = { workspace = true }
+wasmcloud-component-adapters = { workspace = true }
 wasmcloud-control-interface = { workspace = true }
+wat = { workspace = true }
 weld-codegen = { workspace = true }
-wasmbus-rpc = { workspace = true }
 wit-component = { workspace = true }
-wasmcloud-component-adapters = { workspace = true }
+wit-parser = { workspace = true }
 
 [dev-dependencies]
 claims = { workspace = true }

crates/wash-lib/src/build.rs

@@ -1,6 +1,7 @@
 //! Build (and sign) a wasmCloud actor, provider, or interface. Depends on the "cli" feature
 
 use std::{
+    borrow::Cow,
     fs,
     io::ErrorKind,
     path::{Path, PathBuf},
@@ -9,7 +10,8 @@ use std::{
 };
 
 use anyhow::{anyhow, bail, Context, Result};
-use wit_component::ComponentEncoder;
+use wasm_encoder::{Encode, Section};
+use wit_component::{ComponentEncoder, StringEncoding};
 
 use crate::{
     cli::{
@@ -90,10 +92,25 @@ pub fn build_actor(
         LanguageConfig::Rust(rust_config) => {
             build_rust_actor(common_config, rust_config, actor_config)
         }
-        LanguageConfig::TinyGo(tinygo_config) => build_tinygo_actor(common_config, tinygo_config),
+        LanguageConfig::TinyGo(tinygo_config) => {
+            build_tinygo_actor(common_config, tinygo_config, actor_config)
+        }
     }?;
 
-    // If the actor has been configured as WASI Preview2, adapt it
+    // Perform embedding, if necessary
+    if let WasmTarget::WasiPreview1 | WasmTarget::WasiPreview2 = &actor_config.wasm_target {
+        embed_wasm_component_metadata(
+            &common_config.path,
+            actor_config
+                .wit_world
+                .as_ref()
+                .context("`wit_world` must be specified in wasmcloud.toml for creating preview1 or preview2 components")?,
+            &actor_wasm_path,
+            &actor_wasm_path,
+        )?;
+    };
+
+    // If the actor has been configured as WASI Preview2, adapt it from preview1
     if actor_config.wasm_target == WasmTarget::WasiPreview2 {
         let adapter_wasm_bytes = get_wasi_preview2_adapter_bytes(actor_config)?;
         // Adapt the component, using the adapter that is available locally
@@ -219,6 +236,7 @@ fn build_rust_actor(
 fn build_tinygo_actor(
     common_config: &CommonConfig,
     tinygo_config: &TinyGoConfig,
+    actor_config: &ActorConfig,
 ) -> Result<PathBuf> {
     let filename = format!("build/{}.wasm", common_config.name);
 
@@ -240,7 +258,7 @@ fn build_tinygo_actor(
             "-o",
             filename.as_str(),
             "-target",
-            "wasm",
+            tinygo_config.build_target(&actor_config.wasm_target),
             "-scheduler",
             "none",
             "-no-debug",
@@ -321,6 +339,72 @@ pub(crate) fn get_wasi_preview2_adapter_bytes(config: &ActorConfig) -> Result<Ve
     Ok(wasmcloud_component_adapters::WASI_PREVIEW1_REACTOR_COMPONENT_ADAPTER.into())
 }
 
+/// Embed required component metadata to a given WebAssembly binary
+fn embed_wasm_component_metadata(
+    project_path: impl AsRef<Path>,
+    wit_world: impl AsRef<str>,
+    input_wasm: impl AsRef<Path>,
+    output_wasm: impl AsRef<Path>,
+) -> Result<()> {
+    // Find the the WIT directory for the project
+    let wit_dir = project_path.as_ref().join("wit");
+    if !wit_dir.is_dir() {
+        bail!(
+            "expected 'wit' directory under project path at [{}] is missing",
+            wit_dir.display()
+        );
+    };
+
+    // Resolve the WIT directory packages & worlds
+    let mut resolve = wit_parser::Resolve::default();
+    let (package_id, _paths) = resolve
+        .push_dir(&wit_dir)
+        .context("failed to add WIT deps directory")?;
+    log::info!("successfully loaded WIT @ [{}]", wit_dir.display());
+
+    // Select the target world that was specified by the user
+    let world = resolve
+        .select_world(package_id, wit_world.as_ref().into())
+        .context("failed to select world from built resolver")?;
+
+    // Encode the metadata
+    let encoded_metadata =
+        wit_component::metadata::encode(&resolve, world, StringEncoding::UTF8, None)
+            .context("failed to encode WIT metadata for component")?;
+
+    // Load the wasm binary
+    let mut wasm_bytes = wat::parse_file(input_wasm.as_ref()).with_context(|| {
+        format!(
+            "failed to read wasm bytes from [{}]",
+            input_wasm.as_ref().display()
+        )
+    })?;
+
+    // Build & encode a new custom section at the end of the wasm
+    let section = wasm_encoder::CustomSection {
+        name: "component-type".into(),
+        data: Cow::Borrowed(&encoded_metadata),
+    };
+    wasm_bytes.push(section.id());
+    section.encode(&mut wasm_bytes);
+    log::info!("successfully embedded component metadata in WASM");
+
+    // Output the WASM to disk (possibly overwriting the original path)
+    std::fs::write(output_wasm.as_ref(), wasm_bytes).with_context(|| {
+        format!(
+            "failed to write updated wasm to disk at [{}]",
+            output_wasm.as_ref().display()
+        )
+    })?;
+
+    log::info!(
+        "successfully wrote component w/ metadata to [{}]",
+        output_wasm.as_ref().display()
+    );
+
+    Ok(())
+}
+
 /// Placeholder for future functionality for building providers
 #[allow(unused)]
 fn build_provider(