Use conventional testing for windows_slim_errors (#3132)

.cargo/config.toml

@@ -2,5 +2,6 @@
 rustflags = [
     # "--cfg", "windows_debugger_visualizer",
     # "--cfg", "windows_raw_dylib",
+    # "--cfg", "windows_slim_errors",
     # "-C", "target-feature=+crt-static",
 ]

.github/workflows/msrv-windows-result.yml

@@ -29,13 +29,3 @@ jobs:
         run: cargo check -p windows-result --all-features
       - name: Check Default Features
         run: cargo check -p windows-result
-      - name: Check Slim Errors
-        shell: pwsh
-        run: |
-          $ErrorActionPreference = 'Stop'
-          $env:RUSTFLAGS = '--cfg=windows_slim_errors'
-
-          # This will show the size of Error, which lets us confirm that RUSTFLAGS was set.
-          cargo test -p windows-result --lib -- --nocapture --test-threads=1
-
-          cargo check -p windows-result

.github/workflows/slim_errors.yml

@@ -0,0 +1,40 @@
+name: slim_errors
+
+on:
+  pull_request:
+  push:
+    paths-ignore:
+      - '.github/ISSUE_TEMPLATE/**'
+    branches:
+      - master
+
+env:
+  RUSTFLAGS: -Dwarnings --cfg windows_slim_errors
+
+jobs:
+  check:
+    strategy:
+      matrix:
+        include:
+          - target: x86_64-pc-windows-msvc
+          - target: i686-pc-windows-msvc
+          - target: x86_64-pc-windows-gnu
+          - target: i686-pc-windows-gnu
+        runs-on:
+          - windows-latest
+    runs-on: ${{ matrix.runs-on }}
+    steps:
+      - name: Checkout
+        uses: actions/checkout@v4
+
+      - name: Update toolchain
+        run: rustup update --no-self-update nightly && rustup default nightly-${{ matrix.target }}
+
+      - name: Add toolchain target
+        run: rustup target add ${{ matrix.target }}
+
+      - name: Fix environment
+        uses: ./.github/actions/fix-environment
+
+      - name: Test
+        run: cargo test -p test_result

crates/libs/result/Cargo.toml

@@ -21,9 +21,6 @@ workspace = true
 default-target = "x86_64-pc-windows-msvc"
 targets = []
 
-[dependencies]
-static_assertions = "1.0"
-
 [dependencies.windows-targets]
 version = "0.52.5"
 path = "../targets"

crates/libs/result/src/error.rs

@@ -257,8 +257,6 @@ impl Ord for Error {
     }
 }
 
-static_assertions::assert_impl_all!(Error: Send, Sync);
-
 use error_info::*;
 
 #[cfg(all(windows, not(windows_slim_errors)))]
@@ -395,11 +393,4 @@ mod error_info {
             core::ptr::null_mut()
         }
     }
-
-    // If we are using "slim" Error objects, then we can rely on Result<()>
-    // having a representation that is equivalent to HRESULT.
-    static_assertions::const_assert_eq!(
-        size_of::<core::result::Result<(), Error>>(),
-        size_of::<HRESULT>()
-    );
 }

crates/libs/result/src/lib.rs

@@ -36,6 +36,3 @@ pub use hresult::HRESULT;
 
 /// A specialized [`Result`] type that provides Windows error information.
 pub type Result<T> = core::result::Result<T, Error>;
-
-#[cfg(test)]
-mod tests;

crates/tests/result/Cargo.toml

@@ -16,3 +16,7 @@ path = "../../libs/targets"
 
 [dependencies]
 helpers = { package = "test_helpers", path = "../helpers" }
+static_assertions = "1.0"
+
+[lints.rust]
+unexpected_cfgs = { level = "warn", check-cfg = ['cfg(windows_slim_errors)'] }

crates/tests/result/tests/error.rs

@@ -24,8 +24,14 @@ fn new() {
 
     let e = Error::new(E_INVALIDARG, "test message");
     assert_eq!(e.code(), E_INVALIDARG);
-    assert!(!e.as_ptr().is_null());
-    assert_eq!(e.message(), "test message");
+
+    if cfg!(windows_slim_errors) {
+        assert!(e.as_ptr().is_null());
+        assert_eq!(e.message(), "The parameter is incorrect.");
+    } else {
+        assert!(!e.as_ptr().is_null());
+        assert_eq!(e.message(), "test message");
+    }
 }
 
 #[test]

crates/tests/result/tests/hresult.rs

@@ -80,7 +80,12 @@ fn from_result() {
     let result: Result<()> = Err(Error::new(E_INVALIDARG, "test message"));
     let err = HRESULT::from(result).ok().unwrap_err();
     assert_eq!(err.code(), E_INVALIDARG);
-    assert_eq!(err.message(), "test message");
+
+    if cfg!(windows_slim_errors) {
+        assert_eq!(err.message(), "The parameter is incorrect.");
+    } else {
+        assert_eq!(err.message(), "test message");
+    }
 }
 
 #[test]

crates/tests/result/tests/slim_errors.rs

@@ -0,0 +1,12 @@
+use windows_result::*;
+
+#[test]
+fn show_sizes() {
+    use core::mem::size_of;
+
+    static_assertions::assert_impl_all!(Error: Send, Sync);
+
+    if cfg!(windows_slim_errors) {
+        assert_eq!(size_of::<Result<()>>(), size_of::<HRESULT>());
+    }
+}