Improve windows support, test more platforms in ci

.github/workflows/ci.yml

@@ -29,7 +29,11 @@ jobs:
       - run: cargo doc --no-deps --document-private-items
 
   test:
-    runs-on: ubuntu-latest
+    strategy:
+      fail-fast: false
+      matrix:
+        os: [ubuntu-latest, windows-latest, macos-latest]
+    runs-on: ${{ matrix.os }}
     steps:
       - uses: actions/checkout@v4
       - uses: dtolnay/rust-toolchain@stable

src/numbered_dir.rs

@@ -314,8 +314,13 @@ mod tests {
         assert!(dir_0.path().is_dir());
         assert!(dir_1.path().is_dir());
 
-        let current = fs::read_link(parent.path().join("base-current")).unwrap();
-        assert_eq!(dir_1.path(), current);
+        // We know that on windows the first symlink probably didn't get removed, symlinks
+        // are best-effort there.
+        #[cfg(target_family = "unix")]
+        {
+            let current = fs::read_link(parent.path().join("base-current")).unwrap();
+            assert_eq!(dir_1.path(), current);
+        }
     }
 
     #[test]

src/private.rs

@@ -20,6 +20,18 @@ const CARGO_PID_FILE_NAME: &str = "cargo-pid";
 /// Whether we are a cargo sub-process.
 static CARGO_PID: Lazy<Option<Pid>> = Lazy::new(cargo_pid);
 
+#[cfg(target_family = "unix")]
+const CARGO_NAME: &str = "cargo";
+
+#[cfg(target_family = "unix")]
+const NEXTEST_NAME: &str = "cargo-nextest";
+
+#[cfg(target_family = "windows")]
+const CARGO_NAME: &str = "cargo.exe";
+
+#[cfg(target_family = "windows")]
+const NEXTEST_NAME: &str = "cargo-nextest.exe";
+
 /// Returns the process ID of our parent Cargo process.
 ///
 /// If our parent process is not Cargo, `None` is returned.
@@ -43,7 +55,7 @@ fn cargo_pid() -> Option<Pid> {
     let parent = sys.process(ppid)?;
     let parent_exe = parent.exe();
     let parent_file_name = parent_exe.file_name()?;
-    if parent_file_name == OsStr::new("cargo") || parent_file_name == OsStr::new("cargo-nextest") {
+    if parent_file_name == OsStr::new(CARGO_NAME) || parent_file_name == OsStr::new(NEXTEST_NAME) {
         Some(parent.pid())
     } else if parent_file_name == OsStr::new("rustdoc") {
         let ppid = parent.parent()?;
@@ -127,7 +139,10 @@ pub fn extract_test_name_from_backtrace(module_path: &str) -> String {
             }
         }
     }
-    panic!("Cannot determine test name from backtrace");
+
+    // We know that on windows doc tests fall through as the module_path is something like
+    // "rust_out" which is not very useful.  We'll have to just use something.
+    String::from("unknown_test")
 }
 
 #[cfg(test)]