Ensure JS snippets from wasm-bindgen are being copied to dist.

closes #40

CHANGELOG.md

@@ -3,12 +3,20 @@ changelog
 This changelog follows the patterns described here: https://keepachangelog.com/en/1.0.0/.
 
 ## Unreleased
+
+## 0.4.0
 ### added
 - Added support for layered configuration via `Trunk.toml` & environment variables.
 - Added an example `Trunk.toml` to the root of the repository showing all possible config values along with their defaults.
+
+### changed
 - README has been updated with details on how the config system works.
 - Removed a fair amount of code duplication as part of the configuration feature.
-- Trunk now exits with a non-zero code when an error takes place during execution.
+- Added full release automation with optimized release binaries for Linux, MacOS & Windows (all x64).
+
+### fixed
+- Closed [#37](https://github.com/thedodd/trunk/issues/37): Trunk now exits with a non-zero code when an error takes place during execution.
+- Closed [#40](https://github.com/thedodd/trunk/issues/40): Trunk is now copying JS snippets from wasm-bindgen into the dist dir as part of the standard build/watch/serve commands.
 
 ## 0.3.1
 ### fixed

Cargo.toml

@@ -17,6 +17,7 @@ async-std = { version="1.6.3", features=["attributes", "unstable"] }
 cargo_metadata = "0.11.1"
 console = "0.12.0"
 envy = "0.4.1"
+fs_extra = "1.2.0"
 futures = "0.3.5"
 indicatif = "0.15.0"
 nipper = "0.1.8"

src/build.rs

@@ -4,9 +4,9 @@ use std::ffi::OsString;
 use std::path::PathBuf;
 use std::sync::Arc;
 
-use anyhow::{anyhow, bail, ensure, Result};
+use anyhow::{anyhow, bail, Context, ensure, Result};
 use async_process::{Command, Stdio};
-use async_std::fs;
+use async_std::{fs, path};
 use async_std::task::{spawn, spawn_blocking, JoinHandle};
 use cargo_metadata::{Metadata, MetadataCommand, Package};
 use console::Emoji;
@@ -18,6 +18,7 @@ use crate::config::RtcBuild;
 
 const TRUNK_ID: &str = "__trunk-id";
 const HREF_ATTR: &str = "href";
+const SNIPPETS_DIR: &str = "snippets";
 
 /// A system used for building a Rust WASM app & bundling its assets.
 ///
@@ -211,6 +212,7 @@ impl BuildSystem {
     /// Spawn the wasm-bindgen build process.
     fn spawn_wasm_bindgen_build(&self, file_name: String) -> JoinHandle<Result<WasmBindgenOutput>> {
         let (dist, bindgen_out, app_target_wasm) = (self.cfg.dist.clone(), self.bindgen_out.clone(), self.app_target_wasm.clone());
+        let (snippets_dir_from, snippets_dir_to) = (self.bindgen_out.join(SNIPPETS_DIR), self.cfg.dist.join(SNIPPETS_DIR));
 
         self.progress.set_message(&format!("{}starting wasm-bindgen build", Emoji("📦 ", "")));
         spawn(async move {
@@ -228,6 +230,7 @@ impl BuildSystem {
                 .map_err(|err| anyhow!("error spawning wasm-bindgen build: {}", err))?
                 .output()
                 .await;
+
             // Handle build results.
             match build_result {
                 Ok(output) => {
@@ -237,6 +240,7 @@ impl BuildSystem {
                 }
                 Err(err) => return Err(anyhow!("error during wasm-bindgen build: {}", err)),
             }
+
             // Copy the generated WASM & JS loader to the dist dir, and generate the needed body
             // for the output HTML.
             let hashed_js_name = format!("{}.js", &file_name);
@@ -248,13 +252,29 @@ impl BuildSystem {
             fs::copy(js_loader_path, js_loader_path_dist).await?;
             fs::copy(wasm_path, wasm_path_dist).await?;
 
+            // Check for any snippets, and copy them over.
+            Self::copy_dir_recursive(snippets_dir_from, snippets_dir_to).await.with_context(|| "error copying snippets dir")?;
+
             Ok(WasmBindgenOutput {
                 js_output: hashed_js_name,
                 wasm_output: hashed_wasm_name,
             })
         })
     }
 
+    /// A utility function to recursively copy a directory.
+    async fn copy_dir_recursive(from_dir: PathBuf, to_dir: PathBuf) -> Result<()> {
+        if !path::PathBuf::from(&from_dir).exists().await {
+            return Ok(());
+        }
+        spawn_blocking(move || {
+            let opts = fs_extra::dir::CopyOptions{overwrite: true, content_only: true, ..Default::default()};
+            Ok(fs_extra::dir::copy(from_dir, to_dir, &opts)?)
+        })
+        .await
+        .map(|_| ())
+    }
+
     /// Spawn asset building/bundling pipelines.
     ///
     /// Assets are given an ID which corresponds to an ID added to the DOM. Once the processing