CI validates WASM support

For now failure is allowed as no work was done, but this should confirm the crate can at least be compiled
to that target.

We try different targets, including WASI, for good measure, and already build crates that are naturally working.

Author: Byron

.github/workflows/wasm.yml

@@ -0,0 +1,34 @@
+name: WASM
+
+on:
+  push:
+    branches: [ main ]
+    tags-ignore: [ '*' ]
+    paths:
+      - '.github/**'
+      - 'git-pack/**'
+      - '*.toml'
+  pull_request:
+    branches: [ main ]
+    paths:
+      - '.github/**'
+      - 'git-pack/**'
+      - '*.toml'
+
+jobs:
+  wasm:
+    name: WebAssembly
+    runs-on: ubuntu-latest
+    continue-on-error: true
+    strategy:
+      matrix:
+        target: [ wasm32-unknown-unknown, wasm32-wasi ]
+    steps:
+      - uses: actions/checkout@master
+      - name: Install Rust
+        run: rustup update stable && rustup default stable && rustup target add ${{ matrix.target }}
+      - run: set +x; for name in git-hash git-date git-features git-actor git-validate git-object; do (cd $name && cargo build --target ${{ matrix.target }}); done
+        name: naturally working
+      - run: set +x; for feature in rustsha1 zlib crc32 progress; do (cd git-features && cargo build --features $feature --target ${{ matrix.target }}); done
+        name: git-features --features
+#      - run: cargo build -p git-pack --target ${{ matrix.target }} // TODO: make something like it work