Add WASM CI checks and make availability-store compile for WASM (#626)

* Make availability-store compile for WASM

* Use --manifest-path instead

.gitlab-ci.yml

@@ -131,6 +131,23 @@ test-linux-stable:                 &test
     - sccache -s
 
 
+check-web-wasm:                    &test
+  stage:                           test
+  <<:                              *test-refs
+  <<:                              *docker-env
+  <<:                              *compiler_info
+  script:
+    # WASM support is in progress. As more and more crates support WASM, we
+    # should add entries here. See https://github.com/paritytech/polkadot/issues/625
+    - time cargo build --locked --target=wasm32-unknown-unknown --manifest-path availability-store/Cargo.toml
+    - time cargo build --locked --target=wasm32-unknown-unknown --manifest-path executor/Cargo.toml
+    - time cargo build --locked --target=wasm32-unknown-unknown --manifest-path erasure-coding/Cargo.toml
+    - time cargo build --locked --target=wasm32-unknown-unknown --manifest-path parachain/Cargo.toml
+    - time cargo build --locked --target=wasm32-unknown-unknown --manifest-path primitives/Cargo.toml
+    - time cargo build --locked --target=wasm32-unknown-unknown --manifest-path rpc/Cargo.toml
+    - time cargo build --locked --target=wasm32-unknown-unknown --manifest-path runtime/Cargo.toml
+    - time cargo build --locked --target=wasm32-unknown-unknown --manifest-path statement-table/Cargo.toml
+    - sccache -s
 
 
 build-linux-release:               &build

availability-store/Cargo.toml

@@ -12,5 +12,7 @@ log = "0.4.8"
 codec = { package = "parity-scale-codec", version = "1.1.0", default-features = false, features = ["derive"] }
 substrate-primitives = { git = "https://github.com/paritytech/substrate", branch = "polkadot-master" }
 kvdb = "0.1.1"
-kvdb-rocksdb = "0.2"
 kvdb-memorydb = "0.1.2"
+
+[target.'cfg(not(target_os = "unknown"))'.dependencies]
+kvdb-rocksdb = "0.2"

availability-store/src/lib.rs

@@ -22,7 +22,6 @@
 
 use codec::{Encode, Decode};
 use kvdb::{KeyValueDB, DBTransaction};
-use kvdb_rocksdb::{Database, DatabaseConfig};
 use polkadot_primitives::Hash;
 use polkadot_primitives::parachain::{Id as ParaId, BlockData, Message};
 use log::warn;
@@ -74,7 +73,9 @@ pub struct Store {
 
 impl Store {
 	/// Create a new `Store` with given config on disk.
+	#[cfg(not(target_os = "unknown"))]
 	pub fn new(config: Config) -> io::Result<Self> {
+		use kvdb_rocksdb::{Database, DatabaseConfig};
 		let mut db_config = DatabaseConfig::with_columns(Some(columns::NUM_COLUMNS));
 
 		if let Some(cache_size) = config.cache_size {