feat: compile on wasm

.github/workflows/ci.yml

@@ -100,6 +100,33 @@ jobs:
       - name: cargo check
         run: cargo check --workspace --all-features --lib --bins
 
+  wasm_build:
+    name: Build wasm32
+    runs-on: ubuntu-latest
+    env:
+      RUSTFLAGS: '--cfg getrandom_backend="wasm_js"'
+    steps:
+      - name: Checkout sources
+        uses: actions/checkout@v4
+
+      - name: Install stable toolchain
+        uses: dtolnay/rust-toolchain@stable
+
+      - name: Add wasm target
+        run: rustup target add wasm32-unknown-unknown
+
+      - name: Install wasm-tools
+        uses: bytecodealliance/actions/wasm-tools/setup@v1
+
+      - name: wasm32 build
+        run: cargo build --target wasm32-unknown-unknown
+
+      # If the Wasm file contains any 'import "env"' declarations, then
+      # some non-Wasm-compatible code made it into the final code.
+      - name: Ensure no 'import "env"' in wasm
+        run: |
+          ! wasm-tools print --skeleton target/wasm32-unknown-unknown/debug/bao_tree.wasm | grep 'import "env"'
+
 #  minimal-crates:
 #    runs-on: ubuntu-latest
 #    steps: