basic wasm support

.travis.yml

@@ -21,6 +21,11 @@ env:
   global:
     - LD_LIBRARY_PATH: /usr/local/lib
     - CLIPPY: n
+install:
+  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then source $HOME/.nvm/nvm.sh; fi
+  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then nvm install 10; fi
+  - if [ "$TRAVIS_OS_NAME" = "osx" ]; then nvm use 10; fi
+  - if [ "$TRAVIS_RUST_VERSION" != "1.13.0" ]; then curl https://rustwasm.github.io/wasm-pack/installer/init.sh -sSf | sh; fi
 script: ./ci/travis.sh
 notifications:
   email: false

Cargo.toml

@@ -35,13 +35,21 @@ num-traits = { version = "0.2", default-features = false }
 rustc-serialize = { version = "0.3.20", optional = true }
 serde = { version = "1", optional = true }
 
+
+[target.'cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))'.dependencies]
+wasm-bindgen = { version = "0.2" }
+js-sys = "0.3" # contains FFI bindings for the JS Date API
+
 [dev-dependencies]
 serde_json = { version = "1" }
 serde_derive = { version = "1" }
 bincode = { version = "0.8.0" }
 num-iter = { version = "0.1.35", default-features = false }
 doc-comment = "0.3"
 
+[target.'cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))'.dev-dependencies]
+wasm-bindgen-test = "0.2"
+
 [package.metadata.docs.rs]
 all-features = true
 

ci/travis.sh

@@ -48,6 +48,18 @@ build_and_test() {
   channel build -v --no-default-features --features serde,rustc-serialize
   TZ=Asia/Katmandu channel test -v --no-default-features --features serde,rustc-serialize --lib
 
+  if [ -n "${TRAVIS}" ] && [ "${TRAVIS_RUST_VERSION}" != "1.13.0" ]; then
+    # wasm tests
+    touch tests/wasm.rs # ensure rebuild happens so TZ / NOW take effect
+    TZ=ACST-9:30 NOW=$(date +%s) wasm-pack test --node
+    touch tests/wasm.rs
+    TZ=EST4 NOW=$(date +%s) wasm-pack test --node
+    touch tests/wasm.rs
+    TZ=UTC0 NOW=$(date +%s) wasm-pack test --node
+    touch tests/wasm.rs
+    TZ=Asia/Katmandu NOW=$(date +%s) wasm-pack test --node
+  fi
+
   if [[ "$CHANNEL" == stable ]]; then
       if [[ -n "$TRAVIS" ]] ; then
           check_readme
@@ -82,6 +94,7 @@ check_readme() {
 
 rustc --version
 cargo --version
+node --version
 
 CHANNEL=nightly
 if [ "x${CLIPPY}" = xy ] ; then

src/lib.rs

@@ -414,6 +414,10 @@ extern crate serde as serdelib;
 #[cfg(test)]
 #[macro_use]
 extern crate doc_comment;
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
+extern crate wasm_bindgen;
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
+extern crate js_sys;
 
 #[cfg(test)]
 doctest!("../README.md");

src/offset/local.rs

@@ -87,9 +87,21 @@ impl Local {
     }
 
     /// Returns a `DateTime` which corresponds to the current date.
+    #[cfg(not(all(target_arch = "wasm32", not(target_os = "emscripten"))))]
     pub fn now() -> DateTime<Local> {
         tm_to_datetime(oldtime::now())
     }
+
+    /// Returns a `DateTime` which corresponds to the current date.
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
+    pub fn now() -> DateTime<Local> {
+        use super::Utc;
+        let now: DateTime<Utc> = super::Utc::now();
+
+        // Workaround missing timezone logic in `time` crate
+        let offset = FixedOffset::west((js_sys::Date::new_0().get_timezone_offset() as i32) * 60);
+        DateTime::from_utc(now.naive_utc(), offset)
+    }
 }
 
 impl TimeZone for Local {
@@ -179,4 +191,3 @@ mod tests {
                 "unexpected timestr {:?}", timestr);
     }
 }
-

src/offset/utc.rs

@@ -4,7 +4,7 @@
 //! The UTC (Coordinated Universal Time) time zone.
 
 use std::fmt;
-#[cfg(feature="clock")]
+#[cfg(all(feature="clock", not(all(target_arch = "wasm32", not(target_os = "emscripten")))))]
 use oldtime;
 
 use naive::{NaiveDate, NaiveDateTime};
@@ -38,11 +38,23 @@ impl Utc {
     pub fn today() -> Date<Utc> { Utc::now().date() }
 
     /// Returns a `DateTime` which corresponds to the current date.
+    #[cfg(not(all(target_arch = "wasm32", not(target_os = "emscripten"))))]
     pub fn now() -> DateTime<Utc> {
         let spec = oldtime::get_time();
         let naive = NaiveDateTime::from_timestamp(spec.sec, spec.nsec as u32);
         DateTime::from_utc(naive, Utc)
     }
+
+    /// Returns a `DateTime` which corresponds to the current date.
+    #[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
+    pub fn now() -> DateTime<Utc> {
+        let now = js_sys::Date::new_0();
+        let millisecs_since_unix_epoch: u64 = now.get_time() as u64;
+        let secs  = millisecs_since_unix_epoch / 1000;
+        let nanos = 1_000_000 * (millisecs_since_unix_epoch - 1000 * secs);
+        let naive = NaiveDateTime::from_timestamp(secs as i64, nanos as u32);
+        DateTime::from_utc(naive, Utc)
+    }
 }
 
 impl TimeZone for Utc {
@@ -72,4 +84,3 @@ impl fmt::Debug for Utc {
 impl fmt::Display for Utc {
     fn fmt(&self, f: &mut fmt::Formatter) -> fmt::Result { write!(f, "UTC") }
 }
-

tests/wasm.rs

@@ -0,0 +1,30 @@
+#[cfg(all(target_arch = "wasm32", not(target_os = "emscripten")))]
+mod test {
+    extern crate chrono;
+    extern crate wasm_bindgen_test;
+
+    use self::chrono::prelude::*;
+    use self::wasm_bindgen_test::*;
+
+    use std::env;
+
+    #[wasm_bindgen_test]
+    fn now() {
+        let utc: DateTime<Utc> = Utc::now();
+        let local: DateTime<Local> = Local::now();
+
+        // Ensure time fetched is correct
+        let actual = Utc.datetime_from_str(env!("NOW"), "%s").unwrap();
+        assert!(utc - actual < chrono::Duration::minutes(5));
+
+        // Ensure offset retrieved when getting local time is correct
+        let expected_offset = match env!("TZ") {
+            "ACST-9:30" => FixedOffset::east(19 * 30 * 60),
+            "Asia/Katmandu" => FixedOffset::east(23 * 15 * 60), // No DST thankfully
+            "EST4" => FixedOffset::east(-4 * 60 * 60),
+            "UTC0" => FixedOffset::east(0),
+            _ => panic!("unexpected TZ"),
+        };
+        assert_eq!(&expected_offset, local.offset());
+    }
+}