Support compiling the library for wasm32

.github/workflows/check.yml

@@ -31,15 +31,17 @@ jobs:
             target/
           key: ${{ runner.os }}-cargo-clippy-${{ hashFiles('**/Cargo.lock') }}
 
-      # - name: Install WASM toolchain
-      #   run: rustup target add wasm32-unknown-unknown
+      - name: Install WASM toolchain
+        run: rustup target add wasm32-unknown-unknown
 
       - name: Check project
         run: cargo clippy --workspace --all-targets --all-features -- -D warnings
 
-      # - name: Check project (WASM)
-      #   # Note lack of --all-targets here because tests and examples are not wasm compatible
-      #   run: cargo clippy --workspace --all-features --target wasm32-unknown-unknown -- -D warnings
+      - name: Check project (WASM)
+        # Note lack of --all-targets here because tests and examples are not wasm compatible
+        # (the CLI binary compiles as an empty stub). getrandom 0.3 requires selecting its
+        # JS backend explicitly on wasm32-unknown-unknown.
+        run: RUSTFLAGS='--cfg getrandom_backend="wasm_js"' cargo clippy --workspace --all-features --target wasm32-unknown-unknown -- -D warnings
 
   test:
     runs-on: ubuntu-latest

Cargo.toml

@@ -10,18 +10,15 @@ edition = "2024"
 
 [dependencies]
 chrono = { version = "0.4", features = ["serde"] }
-glob = "0.3"
 log = "0.4"
 mime = "0.3"
 rand = "0.8"
 regex = "1"
 sha2 = "0.10"
 uuid = { version = "1", features = ["v4"] }
 
-reqwest = { version = "0.12", features = ["json"] }
 serde = { version = "1", features = ["derive"] }
 serde_json = "1"
-tokio = { version = "1", features = ["full"] }
 
 fontdb = "0.16"
 resvg = "0.41"
@@ -43,7 +40,22 @@ xml5ever = "0.18"
 
 image = { version = "0.25", default-features = false, features = ["bmp", "gif", "jpeg", "png", "webp"] }
 
+slug = "0.1"
+
+# Native-only dependencies: networking, async runtime, filesystem cache, and the CLI.
+# The library builds for wasm32 without them (see src/lib.rs cfg gates); the
+# `Thread::to_epub_remote_images` path is fully available on wasm.
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
+glob = "0.3"
+reqwest = { version = "0.12", features = ["json"] }
+tokio = { version = "1", features = ["full"] }
 clap = { version = "4", features = ["derive"] }
 simple_logger = "4"
-slug = "0.1"
 rpassword = "7.3.1"
+
+# On wasm32-unknown-unknown, getrandom needs its JS backends enabled
+# (pulled in transitively via `rand` and `uuid`).
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+getrandom02 = { package = "getrandom", version = "0.2", features = ["js"] }
+getrandom03 = { package = "getrandom", version = "0.3", features = ["wasm_js"] }
+uuid = { version = "1", features = ["js"] }

src/cached.rs

@@ -57,14 +57,13 @@ impl Replies {
     ) -> Result<Result<Vec<Reply>, Vec<GlowficError>>, Box<dyn Error>> {
         let cache_path = Self::cache_key(id);
 
-        if !invalidate_cache {
-            if let Ok(data) = std::fs::read(&cache_path) {
-                let parsed: Result<Self, Vec<GlowficError>> =
-                    serde_json::from_slice(&data).unwrap();
+        if !invalidate_cache
+            && let Ok(data) = std::fs::read(&cache_path)
+        {
+            let parsed: Result<Self, Vec<GlowficError>> = serde_json::from_slice(&data).unwrap();
 
-                if let Ok(replies) = parsed {
-                    return Ok(Ok(replies.0));
-                }
+            if let Ok(replies) = parsed {
+                return Ok(Ok(replies.0));
             }
         }
 
@@ -88,14 +87,14 @@ impl BoardPosts {
     ) -> Result<Result<Vec<PostInBoard>, Vec<GlowficError>>, Box<dyn Error>> {
         let cache_path = Self::cache_key(id);
 
-        if !invalidate_cache {
-            if let Ok(data) = std::fs::read(&cache_path) {
-                let parsed: Result<Vec<PostInBoard>, Vec<GlowficError>> =
-                    serde_json::from_slice(&data).unwrap();
+        if !invalidate_cache
+            && let Ok(data) = std::fs::read(&cache_path)
+        {
+            let parsed: Result<Vec<PostInBoard>, Vec<GlowficError>> =
+                serde_json::from_slice(&data).unwrap();
 
-                if let Ok(posts) = parsed {
-                    return Ok(Ok(posts));
-                }
+            if let Ok(posts) = parsed {
+                return Ok(Ok(posts));
             }
         }
 
@@ -124,10 +123,10 @@ impl Icon {
             return Err("No url provided for this icon".into());
         };
 
-        if !invalidate_cache {
-            if let Ok((mime, data)) = read_image_file(Self::cache_key(*id, "*")) {
-                return Ok((mime, data));
-            }
+        if !invalidate_cache
+            && let Ok((mime, data)) = read_image_file(Self::cache_key(*id, "*"))
+        {
+            return Ok((mime, data));
         }
 
         log::info!("Downloading icon {id} from {url}");
@@ -232,10 +231,10 @@ pub async fn download_cached_image(
 
     let hash = url_hash(url);
 
-    if !invalidate_cache {
-        if let Ok((mime, data)) = read_image_file(image_cache_key(&hash, "*")) {
-            return Ok((mime, data));
-        }
+    if !invalidate_cache
+        && let Ok((mime, data)) = read_image_file(image_cache_key(&hash, "*"))
+    {
+        return Ok((mime, data));
     }
 
     log::info!("Downloading image {hash} from {url}");
@@ -261,12 +260,12 @@ async fn get_cached_glowfic<T>(
 where
     T: DeserializeOwned + Serialize,
 {
-    if !invalidate_cache {
-        if let Ok(data) = std::fs::read(cache_path) {
-            let parsed: Result<T, Vec<GlowficError>> = serde_json::from_slice(&data).unwrap();
-            if parsed.is_ok() {
-                return Ok(parsed);
-            }
+    if !invalidate_cache
+        && let Ok(data) = std::fs::read(cache_path)
+    {
+        let parsed: Result<T, Vec<GlowficError>> = serde_json::from_slice(&data).unwrap();
+        if parsed.is_ok() {
+            return Ok(parsed);
         }
     }
     let response = crate::api::get_glowfic(url).await?;