Add real wasm32 smoke tests and CI job

.cargo/config.toml

@@ -5,3 +5,17 @@
 # See crates/xtask/src/main.rs for available commands
 xtask = "run --package xtask --"
 dev-setup = "xtask dev-setup"
+
+[target.wasm32-unknown-unknown]
+runner = "wasm-bindgen-test-runner"
+# Mirror the rustflags used by wasm-quarto-hub-client/.cargo/config.toml so any
+# wasm32 build invoked from the workspace root (e.g. the pampa wasm_lua test)
+# gets the same panic strategy and ABI. Without panic=unwind plus the
+# exception-handling target feature, wasm-c-shim's catch_unwind-based
+# replacement for Lua's setjmp/longjmp can't catch panics, and any Lua throw
+# during mlua initialization aborts the wasm module.
+rustflags = [
+    "-C", "target-feature=+bulk-memory,+exception-handling",
+    "-C", "panic=unwind",
+    "-Zwasm-c-abi=spec",
+]

.claude/rules/wasm.md

@@ -13,3 +13,14 @@ Correct pattern:
 #[cfg(not(target_arch = "wasm32"))]
 // Native code (full Lua stdlib via Lua::new())
 ```
+
+## Verify WASM tests when editing WASM code
+
+When modifying any of these files, update `crates/pampa/tests/wasm_lua.rs`:
+- `crates/pampa/src/lua/filter.rs` (cfg(target_arch = "wasm32") blocks)
+- `crates/pampa/src/lua/shortcode.rs` (cfg(target_arch = "wasm32") blocks)
+- `crates/pampa/src/lua/io_wasm.rs`
+- `crates/pampa/src/lua/os_wasm.rs`
+
+WASM tests can't run locally on Windows — they run in Linux CI.
+See `dev-docs/wasm.md` for the local run command (Linux/macOS).

.github/workflows/hub-client-e2e.yml

@@ -32,11 +32,9 @@ jobs:
             [ "$time" != "@0" ] && touch -d "$time" "$file" 2>/dev/null || true
           done
 
-      # Rust toolchain for WASM build
-      - name: Set up Rust nightly
-        uses: dtolnay/rust-toolchain@nightly
-        with:
-          targets: wasm32-unknown-unknown
+      # Install toolchain from rust-toolchain.toml (nightly + components + targets)
+      - name: Set up Rust
+        run: rustup show active-toolchain
 
       - name: Set up Clang
         uses: egor-tensin/setup-clang@v2
@@ -48,9 +46,6 @@ jobs:
         with:
           cache-on-failure: true
 
-      - name: Install wasm-pack
-        run: cargo install wasm-pack
-
       # tree-sitter for grammar builds
       - name: Set up tree-sitter CLI
         run: |

.github/workflows/test-suite.yml

@@ -46,13 +46,9 @@ jobs:
         id: set-up-homebrew
         uses: Homebrew/actions/setup-homebrew@main
 
-      # Consistent Rust setup for both platforms
-      - name: Set up Rust nightly
-        uses: dtolnay/rust-toolchain@nightly
-
-      - name: Output rust version
-        shell: bash
-        run: rustup --version
+      # Install toolchain from rust-toolchain.toml (nightly + components + targets)
+      - name: Set up Rust
+        run: rustup show active-toolchain
 
       # Cache Rust AFTER toolchain is set up
       - name: Cache Rust dependencies
@@ -133,3 +129,42 @@ jobs:
         run: cargo nextest run
         env:
           RUSTFLAGS: "-D warnings"
+
+  wasm-tests:
+    name: WASM Tests
+    runs-on: ubuntu-latest
+    # Override rust-toolchain.toml so the rustup proxy doesn't auto-install the
+    # prebuilt wasm32-unknown-unknown target. We need -Zbuild-std to rebuild
+    # core from source, and the prebuilt sysroot causes E0152 (duplicate lang
+    # item). The production WASM build avoids this because wasm-quarto-hub-client
+    # is excluded from the workspace and gets an isolated target/ directory.
+    env:
+      RUSTUP_TOOLCHAIN: nightly
+    steps:
+      - uses: actions/checkout@v4
+        with:
+          fetch-depth: 1
+
+      - name: Install Rust nightly with rust-src
+        run: rustup toolchain install nightly --component rust-src --profile minimal
+
+      - name: Set up Clang
+        uses: egor-tensin/setup-clang@v1
+        with:
+          version: latest
+          platform: x64
+
+      - name: Rust cache
+        uses: Swatinem/rust-cache@v2
+        with:
+          shared-key: rust-wasm-tests
+
+      - name: Install wasm-bindgen-cli
+        run: cargo xtask dev-setup
+
+      - name: Run WASM tests
+        run: |
+          CC_wasm32_unknown_unknown=clang \
+          CFLAGS_wasm32_unknown_unknown="-isystem ${{ github.workspace }}/crates/wasm-quarto-hub-client/wasm-sysroot -fno-builtin" \
+          cargo test -p pampa --test wasm_lua --target wasm32-unknown-unknown \
+            --no-default-features --features lua-filter -Zbuild-std=std,panic_unwind,panic_abort

.github/workflows/ts-test-suite.yml

@@ -46,13 +46,9 @@ jobs:
         id: set-up-homebrew
         uses: Homebrew/actions/setup-homebrew@main
 
-      # Consistent Rust setup for both platforms
-      - name: Set up Rust nightly
-        uses: dtolnay/rust-toolchain@nightly
-
-      - name: Output rust version
-        shell: bash
-        run: rustup --version
+      # Install toolchain from rust-toolchain.toml (nightly + components + targets)
+      - name: Set up Rust
+        run: rustup show active-toolchain
 
     #   # Cache Rust AFTER toolchain is set up
     #   - name: Cache Rust dependencies

CLAUDE.md

@@ -228,11 +228,11 @@ When fixing ANY bug:
 - `quarto-treesitter-ast`: generic tree-sitter AST traversal utilities
 
 **WASM:**
-- `wasm-qmd-parser`: WASM module with entry points from `pampa` (see [crates/wasm-qmd-parser/CLAUDE.md](crates/wasm-qmd-parser/CLAUDE.md) for build instructions)
+- `wasm-quarto-hub-client`: WASM client for hub-client (see [crates/wasm-quarto-hub-client/README.md](crates/wasm-quarto-hub-client/README.md) for build instructions)
 
 ### `hub-client/` - Quarto Hub web client
 
-A React/TypeScript web application for collaborative editing of Quarto projects. Uses Automerge for real-time sync and the WASM build of `wasm-qmd-parser` for live preview rendering.
+A React/TypeScript web application for collaborative editing of Quarto projects. Uses Automerge for real-time sync and the WASM build of `wasm-quarto-hub-client` for live preview rendering.
 
 **Key directories:**
 - `src/components/` - React components (Editor, FileSidebar, tabs, etc.)
@@ -266,7 +266,7 @@ All VFS file paths use the `/project/` prefix. When resolving file paths in WASM
 
 - `pampa` is the core Quarto engine crate
 - `quarto-core` handles higher-level orchestration
-- `wasm-quarto-hub-client` is the WASM client (NOT wasm-qmd-parser)
+- `wasm-quarto-hub-client` is the WASM client for hub-client
 - Always check `git diff` for uncommitted changes before starting work on a continuation session
 
 ## hub-client Commit Instructions

Cargo.toml

@@ -5,10 +5,10 @@ members = [
 ]
 default-members = ["crates/*", "crates/experiments/reconcile-viewer"]
 # Excluded crates require special build toolchains or targets:
-# - WASM crates: build with wasm-pack or --target wasm32-unknown-unknown
+# - WASM crates: require --target wasm32-unknown-unknown and -Zbuild-std (see dev-docs/wasm.md)
 # - pampa/fuzz: requires nightly Rust + libfuzzer-sys (Linux/macOS only), run via `cargo fuzz`
 # crates/experiments is a container directory, not a crate, so we exclude it from crates/* matching.
-exclude = ["crates/wasm-quarto-hub-client", "crates/wasm-qmd-parser", "crates/experiments", "crates/pampa/fuzz"]
+exclude = ["crates/wasm-quarto-hub-client", "crates/experiments", "crates/pampa/fuzz"]
 resolver = "2"
 
 [workspace.package]
@@ -83,9 +83,6 @@ path = "./crates/tree-sitter-qmd"
 [workspace.dependencies.tree-sitter-sexpr]
 path = "./crates/tree-sitter-sexpr"
 
-[workspace.dependencies.wasm-qmd-parser]
-path = "./crates/wasm-qmd-parser"
-
 [workspace.dependencies.pampa]
 path = "./crates/pampa"
 default-features = false
@@ -250,6 +247,6 @@ lua-src = { path = "crates/lua-src-wasm" }
 # Profiles must be set at the workspace level
 [profile.dev]
 # Tell `rustc` to optimize for small code size to
-# work around "too many locals" error from wasm-pack
+# work around "too many locals" error in WASM builds
 # https://github.com/wasm-bindgen/wasm-bindgen/issues/3451#issuecomment-1562982835
 opt-level = "s"