tracing: generate macro tests

.github/workflows/CI.yml

@@ -314,6 +314,21 @@ jobs:
     - name: "Test tracing-mock with all features enabled"
       run: cargo test --all-features -p tracing-mock
 
+  check-tracing-macros-stable:
+    # Feature flag tests that run on stable Rust.
+    name: cargo check (tracing macros)
+    needs: check
+    runs-on: ubuntu-latest
+    steps:
+    - uses: actions/checkout@v4
+    - uses: dtolnay/rust-toolchain@stable
+    - name: "Generate macro tests"
+      run: cargo run --bin xtask -- gen-macro-tests
+    - name: "Check tracing macro invocations ("
+      # TODO(hds): remove `|| true` when all macros compile
+      run: cargo check --tests || true
+      working-directory: "tracing/test-macros"
+
   # all required checks except for the main test run (which we only require
   # specific matrix combinations from)
   all_required:
@@ -326,5 +341,6 @@ jobs:
       - test-build-wasm
       - test-wasm
       - test-features-stable
+      - check-tracing-macros-stable
     steps:
       - run: exit 0

Cargo.toml

@@ -16,7 +16,8 @@ members = [
     "tracing-test",
     "tracing-appender",
     "tracing-journald",
-    "examples"
+    "examples",
+    "xtask",
 ]
 
  # This will be ignored with Rust older than 1.74, but for now that's okay;

tracing/test-macros/Cargo.toml

@@ -0,0 +1,10 @@
+[workspace]
+
+[package]
+name = "test-macros"
+version = "0.1.0"
+publish = false
+edition = "2018"
+
+[dependencies]
+tracing = { path = ".." }

tracing/test-macros/tests/.gitignore

@@ -0,0 +1 @@
+*

xtask/Cargo.toml

@@ -0,0 +1,11 @@
+[package]
+name = "xtask"
+version = "0.1.0"
+edition = "2018"
+publish = false
+
+[dependencies]
+clap = { version = "4.5", features = ["derive"] }
+
+[lints]
+workspace = true