refactor git-path tests

gix-path/tests/path/env.rs

@@ -0,0 +1,61 @@
+#[test]
+fn exe_invocation() {
+    let actual = gix_path::env::exe_invocation();
+    assert!(
+        !actual.as_os_str().is_empty(),
+        "it finds something as long as git is installed somewhere on the system (or a default location)"
+    );
+}
+
+#[test]
+fn installation_config() {
+    assert_ne!(
+        gix_path::env::installation_config().map(|p| p.components().count()),
+        gix_path::env::installation_config_prefix().map(|p| p.components().count()),
+        "the prefix is a bit shorter than the installation config path itself"
+    );
+}
+
+#[test]
+fn system_prefix() {
+    assert_ne!(
+        gix_path::env::system_prefix(),
+        None,
+        "git should be present when running tests"
+    );
+}
+
+#[test]
+fn home_dir() {
+    assert_ne!(
+        gix_path::env::home_dir(),
+        None,
+        "we find a home on every system these tests execute"
+    );
+}
+
+mod xdg_config {
+    use std::ffi::OsStr;
+
+    #[test]
+    fn prefers_xdg_config_bases() {
+        let actual = gix_path::env::xdg_config("test", &mut |n| {
+            (n == OsStr::new("XDG_CONFIG_HOME")).then(|| "marker".into())
+        })
+        .expect("set");
+        #[cfg(unix)]
+        assert_eq!(actual.to_str(), Some("marker/git/test"));
+        #[cfg(windows)]
+        assert_eq!(actual.to_str(), Some("marker\\git\\test"));
+    }
+
+    #[test]
+    fn falls_back_to_home() {
+        let actual = gix_path::env::xdg_config("test", &mut |n| (n == OsStr::new("HOME")).then(|| "marker".into()))
+            .expect("set");
+        #[cfg(unix)]
+        assert_eq!(actual.to_str(), Some("marker/.config/git/test"));
+        #[cfg(windows)]
+        assert_eq!(actual.to_str(), Some("marker\\.config\\git\\test"));
+    }
+}

gix-path/tests/path/main.rs

@@ -0,0 +1,18 @@
+pub type Result<T = ()> = std::result::Result<T, Box<dyn std::error::Error>>;
+
+mod convert;
+mod realpath;
+mod home_dir {
+    #[test]
+    fn returns_existing_directory() {
+        if let Some(home) = gix_path::env::home_dir() {
+            assert!(
+                home.is_dir(),
+                "the home directory would typically exist, even though on unix we don't test for that."
+            );
+        }
+    }
+}
+
+mod env;
+mod util;