fix: ensure cosmian_logger build on wasm - even not used on wasm

.github/workflows/ci.yml

@@ -22,6 +22,17 @@ jobs:
       - name: Tests all targets all features
         run: cargo test --lib --workspace --all-targets --all-features
 
+  wasm-build:
+    runs-on: ubuntu-22.04
+    steps:
+      - uses: actions/checkout@v4
+      - uses: dtolnay/rust-toolchain@master
+        with:
+          toolchain: 1.90.0
+          targets: wasm32-unknown-unknown
+      - name: Build cosmian_logger for wasm32-unknown-unknown
+        run: cargo build --target wasm32-unknown-unknown -p cosmian_logger
+
   cargo-lint:
     uses: Cosmian/reusable_workflows/.github/workflows/cargo-lint.yml@develop
     with:

.pre-commit-config.yaml

@@ -4,6 +4,7 @@
 # pre-commit install
 # pre-commit install --install-hooks -t commit-msg
 # pre-commit autoupdate
+# rustup target add wasm32-unknown-unknown
 #
 # (optional) Creating a virtual environment
 # ```
@@ -148,3 +149,9 @@ repos:
         language: system
         pass_filenames: false
         always_run: true
+      - id: wasm-build-cosmian-logger
+        name: WASM build - cosmian_logger
+        entry: cargo build --target wasm32-unknown-unknown -p cosmian_logger
+        language: system
+        pass_filenames: false
+        files: ^crate/logger/

crate/logger/Cargo.toml

@@ -8,32 +8,33 @@ license.workspace = true
 
 [dependencies]
 opentelemetry = "0.32"
+opentelemetry-semantic-conventions = "0.32"
+thiserror = { workspace = true }
+tracing = { workspace = true }
+tracing-subscriber = { workspace = true, features = [
+    "ansi",
+    "env-filter",
+    "fmt",
+    "std"
+] }
+
+# The following crates rely on tokio, tonic, or Unix-specific syscalls that do
+# not compile on wasm32.
+[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 opentelemetry-appender-tracing = "0.32"
 opentelemetry-otlp = { version = "0.32", features = [
     "metrics",
     "logs",
     "grpc-tonic"
 ] }
-opentelemetry-semantic-conventions = "0.32"
 opentelemetry_sdk = { version = "0.32", features = [
     "metrics",
     "logs",
     "rt-tokio"
 ] }
-thiserror = { workspace = true }
 syslog-tracing = "0.3"
-tracing = { workspace = true }
-tracing-opentelemetry = { version = "0.33" }
-tracing-subscriber = { workspace = true, features = [
-    "ansi",
-    "env-filter",
-    "fmt",
-    "std"
-] }
-
-# tracing-appender uses platform-specific file rotation that does not compile on wasm32.
-[target.'cfg(not(target_arch = "wasm32"))'.dependencies]
 tracing-appender = { workspace = true }
+tracing-opentelemetry = { version = "0.33" }
 
 [dev-dependencies]
 tokio = { version = "1", features = ["rt-multi-thread", "macros"] }

crate/logger/src/error.rs

@@ -1,12 +1,15 @@
 /// Errors that can occur while initialising or configuring the logging stack.
 #[derive(Debug, thiserror::Error)]
 pub enum LoggingError {
+    #[cfg(not(target_arch = "wasm32"))]
     #[error("failed to build OTLP span exporter: {0}")]
     SpanExporter(#[source] opentelemetry_otlp::ExporterBuildError),
 
+    #[cfg(not(target_arch = "wasm32"))]
     #[error("failed to build OTLP log exporter: {0}")]
     LogExporter(#[source] opentelemetry_otlp::ExporterBuildError),
 
+    #[cfg(not(target_arch = "wasm32"))]
     #[error("failed to build OTLP metric exporter: {0}")]
     MetricExporter(#[source] opentelemetry_otlp::ExporterBuildError),