Merge pull request #189 from bschoenmaeckers/emscripten

Add support for emscripten

Author: astraw

.github/workflows/rust.yml

@@ -108,6 +108,29 @@ jobs:
           tool: wasm-pack
       - run: wasm-pack test --node
 
+  test-emscripten:
+    strategy:
+      fail-fast: false
+      matrix:
+        toolchain:
+          - stable
+          - nightly
+    runs-on: ubuntu-latest
+    steps:
+      - name: Checkout
+        uses: actions/checkout@8e8c483db84b4bee98b60c0593521ed34d9990e8 # v6
+        with:
+          persist-credentials: false
+      - name: Install Rust
+        run: |
+          rustup toolchain install ${{ matrix.toolchain }} --profile minimal --no-self-update --target wasm32-unknown-emscripten
+          rustup default ${{ matrix.toolchain }}
+      - uses: mymindstorm/setup-emsdk@6ab9eb1bda2574c4ddb79809fc9247783eaf9021 # v14
+      - env:
+          CARGO_TARGET_WASM32_UNKNOWN_EMSCRIPTEN_RUNNER: node
+          CARGO_BUILD_TARGET: wasm32-unknown-emscripten
+        run: cargo test
+
   build-cross:
     strategy:
       fail-fast: false

src/lib.rs

@@ -45,6 +45,10 @@ mod ffi_utils;
     all(target_arch = "wasm32", target_os = "unknown"),
     path = "tz_wasm32_unknown.rs"
 )]
+#[cfg_attr(
+    all(target_arch = "wasm32", target_os = "emscripten"),
+    path = "tz_wasm32_emscripten.rs"
+)]
 #[cfg_attr(
     any(target_os = "freebsd", target_os = "dragonfly"),
     path = "tz_freebsd.rs"

src/platform.rs

@@ -5,5 +5,5 @@ pub fn get_timezone_inner() -> Result<String, crate::GetTimezoneError> {
 #[cfg(not(feature = "fallback"))]
 compile_error!(
     "iana-time-zone is currently implemented for Linux, Window, MacOS, FreeBSD, NetBSD, \
-    OpenBSD, Dragonfly, WebAssembly (browser), iOS, Illumos, Android, AIX, Solaris and Haiku.",
+    OpenBSD, Dragonfly, WebAssembly (browser), emscripten, iOS, Illumos, Android, AIX, Solaris and Haiku.",
 );

src/tz_wasm32_emscripten.rs

@@ -0,0 +1,30 @@
+use crate::GetTimezoneError;
+use std::ffi::CStr;
+use std::os::raw::c_char;
+use std::ptr::NonNull;
+
+extern "C" {
+    fn emscripten_run_script_string(script: *const c_char) -> *mut c_char;
+}
+
+pub(crate) fn get_timezone_inner() -> Result<String, GetTimezoneError> {
+    const SCRIPT: &CStr = {
+        match CStr::from_bytes_with_nul(
+            "Intl.DateTimeFormat().resolvedOptions().timeZone\0".as_bytes(),
+        ) {
+            Ok(s) => s,
+            Err(_) => panic!("Invalid UTF-8 data"),
+        }
+    };
+
+    unsafe {
+        NonNull::new(emscripten_run_script_string(SCRIPT.as_ptr()))
+            .ok_or_else(|| GetTimezoneError::OsError)
+            .and_then(|ptr| {
+                CStr::from_ptr(ptr.as_ptr())
+                    .to_owned()
+                    .into_string()
+                    .map_err(|_| GetTimezoneError::FailedParsingString)
+            })
+    }
+}