[red-knot] Add basic WASM API (astral-sh#12654)

.github/workflows/ci.yaml

@@ -111,7 +111,7 @@ jobs:
       - name: "Clippy"
         run: cargo clippy --workspace --all-targets --all-features --locked -- -D warnings
       - name: "Clippy (wasm)"
-        run: cargo clippy -p ruff_wasm --target wasm32-unknown-unknown --all-features --locked -- -D warnings
+        run: cargo clippy -p ruff_wasm -p red_knot_wasm --target wasm32-unknown-unknown --all-features --locked -- -D warnings
 
   cargo-test-linux:
     name: "cargo test (linux)"
@@ -191,10 +191,14 @@ jobs:
           cache-dependency-path: playground/package-lock.json
       - uses: jetli/wasm-pack-action@v0.4.0
       - uses: Swatinem/rust-cache@v2
-      - name: "Run wasm-pack"
+      - name: "Test ruff_wasm"
         run: |
           cd crates/ruff_wasm
           wasm-pack test --node
+      - name: "Test red_knot_wasm"
+        run: |
+          cd crates/red_knot_wasm
+          wasm-pack test --node
 
   cargo-build-release:
     name: "cargo build (release)"

Cargo.toml

@@ -152,7 +152,7 @@ walkdir = { version = "2.3.2" }
 wasm-bindgen = { version = "0.2.92" }
 wasm-bindgen-test = { version = "0.3.42" }
 wild = { version = "2" }
-zip = { version = "0.6.6", default-features = false, features = ["zstd"] }
+zip = { version = "0.6.6", default-features = false }
 
 [workspace.lints.rust]
 unsafe_code = "warn"

crates/red_knot_module_resolver/Cargo.toml

@@ -25,7 +25,7 @@ zip = { workspace = true }
 [build-dependencies]
 path-slash = { workspace = true }
 walkdir = { workspace = true }
-zip = { workspace = true }
+zip = { workspace = true, features = ["zstd", "deflate"] }
 
 [dev-dependencies]
 ruff_db = { workspace = true, features = ["os"] }

crates/red_knot_module_resolver/build.rs

@@ -23,8 +23,21 @@ const TYPESHED_ZIP_LOCATION: &str = "/zipped_typeshed.zip";
 fn zip_dir(directory_path: &str, writer: File) -> ZipResult<File> {
     let mut zip = ZipWriter::new(writer);
 
+    // Use deflated compression for WASM builds because compiling `zstd-sys` requires clang
+    // [source](https://github.com/gyscos/zstd-rs/wiki/Compile-for-WASM) which complicates the build
+    // by a lot. Deflated compression is slower but it shouldn't matter much for the WASM use case
+    // (WASM itself is already slower than a native build for a specific platform).
+    // We can't use `#[cfg(...)]` here because the target-arch in a build script is the
+    // architecture of the system running the build script and not the architecture of the build-target.
+    // That's why we use the `TARGET` environment variable here.
+    let method = if std::env::var("TARGET").unwrap().contains("wasm32") {
+        CompressionMethod::Deflated
+    } else {
+        CompressionMethod::Zstd
+    };
+
     let options = FileOptions::default()
-        .compression_method(CompressionMethod::Zstd)
+        .compression_method(method)
         .unix_permissions(0o644);
 
     for entry in walkdir::WalkDir::new(directory_path) {

crates/red_knot_wasm/Cargo.toml

@@ -0,0 +1,38 @@
+[package]
+name = "red_knot_wasm"
+version = "0.0.0"
+publish = false
+authors = { workspace = true }
+edition = { workspace = true }
+rust-version = { workspace = true }
+homepage = { workspace = true }
+documentation = { workspace = true }
+repository = { workspace = true }
+license = { workspace = true }
+description = "WebAssembly bindings for Red Knot"
+
+[lib]
+crate-type = ["cdylib", "rlib"]
+doctest = false
+
+[features]
+default = ["console_error_panic_hook"]
+
+[dependencies]
+red_knot_workspace = { workspace = true }
+
+ruff_db = { workspace = true }
+ruff_notebook = { workspace = true }
+
+console_error_panic_hook = { workspace = true, optional = true }
+console_log = { workspace = true }
+js-sys = { workspace = true }
+log = { workspace = true }
+wasm-bindgen = { workspace = true }
+wee_alloc = "0.4.5"
+
+[dev-dependencies]
+wasm-bindgen-test = { workspace = true }
+
+[lints]
+workspace = true