Adds WebAssembly support to Oxigraph lib

.github/workflows/build.yml

@@ -31,4 +31,12 @@ jobs:
     - run: cargo build
     - run: cargo test --verbose --all
       env:
-        RUST_BACKTRACE: 1
+        RUST_BACKTRACE: 1
+
+  wasm:
+    runs-on: ubuntu-latest
+    steps:
+      - uses: actions/checkout@v1
+      - run: rustup update
+      - run: cargo install wasm-pack
+      - run: wasm-pack test --node lib

lib/Cargo.toml

@@ -29,8 +29,14 @@ rio_xml = "0.4"
 hex = "0.4"
 nom = "5"
 
+[target.'cfg(target_arch = "wasm32")'.dependencies]
+js-sys = "0.3"
+
 [dev-dependencies]
 rayon = "1"
 
+[target.'cfg(target_arch = "wasm32")'.dev-dependencies]
+wasm-bindgen-test = "0.3"
+
 [build-dependencies]
 peg = "0.5"

lib/src/model/xsd/date_time.rs

@@ -579,12 +579,7 @@ impl Timestamp {
     fn now() -> Result<Self, DateTimeError> {
         Timestamp::new(
             &date_time_plus_duration(
-                SystemTime::now()
-                    .duration_since(SystemTime::UNIX_EPOCH)?
-                    .try_into()
-                    .map_err(|_| DateTimeError {
-                        kind: DateTimeErrorKind::Overflow,
-                    })?,
+                since_unix_epoch()?,
                 &DateTimeSevenPropertyModel {
                     year: Some(1970),
                     month: Some(1),
@@ -757,6 +752,24 @@ impl Timestamp {
     }
 }
 
+#[cfg(target_arch = "wasm32")]
+fn since_unix_epoch() -> Result<Duration, DateTimeError> {
+    Ok(Duration::new(
+        0,
+        Decimal::from_f64(js_sys::Date::now() / 1000.),
+    ))
+}
+
+#[cfg(not(target_arch = "wasm32"))]
+fn since_unix_epoch() -> Result<Duration, DateTimeError> {
+    SystemTime::now()
+        .duration_since(SystemTime::UNIX_EPOCH)?
+        .try_into()
+        .map_err(|_| DateTimeError {
+            kind: DateTimeErrorKind::Overflow,
+        })
+}
+
 /// The [normalizeMonth](https://www.w3.org/TR/xmlschema11-2/#f-dt-normMo) function
 fn normalize_month(yr: i64, mo: i64) -> Option<(i64, u8)> {
     if mo >= 0 {

lib/tests/wasm.rs

@@ -0,0 +1,57 @@
+#[cfg(target_arch = "wasm32")]
+mod test {
+    use oxigraph::model::*;
+    use oxigraph::sparql::{PreparedQuery, QueryOptions, QueryResult};
+    use oxigraph::{MemoryRepository, Repository, RepositoryConnection, Result};
+    use std::str::FromStr;
+    use wasm_bindgen_test::*;
+
+    #[wasm_bindgen_test]
+    fn simple() {
+        let repository = MemoryRepository::default();
+        let mut connection = repository.connection().unwrap();
+
+        // insertion
+        let ex = NamedNode::parse("http://example.com").unwrap();
+        let quad = Quad::new(ex.clone(), ex.clone(), ex.clone(), None);
+        connection.insert(&quad).unwrap();
+        // quad filter
+        let results: Result<Vec<Quad>> = connection
+            .quads_for_pattern(None, None, None, None)
+            .collect();
+        assert_eq!(vec![quad], results.unwrap());
+
+        // SPARQL query
+        let prepared_query = connection
+            .prepare_query("SELECT ?s WHERE { ?s ?p ?o }", QueryOptions::default())
+            .unwrap();
+        let results = prepared_query.exec().unwrap();
+        if let QueryResult::Bindings(results) = results {
+            assert_eq!(
+                results.into_values_iter().next().unwrap().unwrap()[0],
+                Some(ex.into())
+            );
+        }
+    }
+
+    #[wasm_bindgen_test]
+    fn now() {
+        if let QueryResult::Bindings(results) = MemoryRepository::default()
+            .connection()
+            .unwrap()
+            .prepare_query(
+                "SELECT (YEAR(NOW()) AS ?y) WHERE {}",
+                QueryOptions::default(),
+            )
+            .unwrap()
+            .exec()
+            .unwrap()
+        {
+            if let Some(Term::Literal(l)) = &results.into_values_iter().next().unwrap().unwrap()[0]
+            {
+                let year = i64::from_str(l.value()).unwrap();
+                assert!(2020 <= year && year <= 2100);
+            }
+        }
+    }
+}