Move new tests up into a tests subdirectory

The new tests of `gix_testtools::Env` are effectively end-to-end
tests, since they are involve modifying the actual environment, and
more importantly they are only testing the public surface of the
crate (`Env` is public), and therefore need not be inside any
non-test module.

So this moves from residing inside the nested `tests::env` module
within `tests/tools/src/lib.rs`, into the newly created
`tests/tools/tests/env.rs`.

(As expected, they still all pass, and when the fix in
`tests/tools/src/lib.rs` is temporarily undone, the `overlapping_*`
tests fail again, confirming they still work as regression tests.)

Author: EliahKagan

tests/tools/src/lib.rs

@@ -883,98 +883,4 @@ mod tests {
     fn parse_version_with_trailing_newline() {
         assert_eq!(git_version_from_bytes(b"git version 2.37.2\n").unwrap(), (2, 37, 2));
     }
-
-    mod env {
-        use super::Env;
-        use serial_test::serial;
-
-        // We rely on these not already existing, to test `Env` without using or rewriting it.
-        static VAR1: &str = "VAR_03FC4045_6043_4A61_9D15_852236CB632B";
-        static VAR2: &str = "VAR_8C135840_05DB_4F3A_BFDD_FC755EC35B89";
-        static VAR3: &str = "VAR_9B23A2BE_E20B_4670_93E2_3A6A8D47F274";
-
-        struct TestEnv;
-
-        impl TestEnv {
-            fn new() -> Self {
-                assert_eq!(std::env::var_os(VAR1), None);
-                assert_eq!(std::env::var_os(VAR2), None);
-                assert_eq!(std::env::var_os(VAR3), None);
-                Self
-            }
-        }
-
-        impl Drop for TestEnv {
-            fn drop(&mut self) {
-                std::env::remove_var(VAR1);
-                std::env::remove_var(VAR2);
-                std::env::remove_var(VAR3);
-            }
-        }
-
-        #[test]
-        #[serial]
-        fn nonoverlapping() {
-            let _meta = TestEnv::new();
-            std::env::set_var(VAR1, "old1");
-            std::env::set_var(VAR2, "old2");
-            {
-                let _env = Env::new().set(VAR1, "new1").unset(VAR2).set(VAR3, "new3");
-                assert_eq!(std::env::var_os(VAR1), Some("new1".into()));
-                assert_eq!(std::env::var_os(VAR2), None);
-                assert_eq!(std::env::var_os(VAR3), Some("new3".into()));
-            }
-            assert_eq!(std::env::var_os(VAR1), Some("old1".into()));
-            assert_eq!(std::env::var_os(VAR2), Some("old2".into()));
-            assert_eq!(std::env::var_os(VAR3), None);
-        }
-
-        #[test]
-        #[serial]
-        fn overlapping_reset() {
-            let _meta = TestEnv::new();
-            {
-                let _env = Env::new().set(VAR1, "new1A").set(VAR1, "new1B");
-                assert_eq!(std::env::var_os(VAR1), Some("new1B".into()));
-            }
-            assert_eq!(std::env::var_os(VAR1), None);
-        }
-
-        #[test]
-        #[serial]
-        fn overlapping_unset() {
-            let _meta = TestEnv::new();
-            std::env::set_var(VAR1, "old1");
-            {
-                let _env = Env::new().unset(VAR1).unset(VAR1);
-                assert_eq!(std::env::var_os(VAR1), None);
-            }
-            assert_eq!(std::env::var_os(VAR1), Some("old1".into()));
-        }
-
-        #[test]
-        #[serial]
-        fn overlapping_combo() {
-            let _meta = TestEnv::new();
-            std::env::set_var(VAR1, "old1");
-            std::env::set_var(VAR2, "old2");
-            {
-                let _env = Env::new()
-                    .set(VAR1, "new1A")
-                    .unset(VAR2)
-                    .set(VAR1, "new1B")
-                    .unset(VAR3)
-                    .set(VAR2, "new2")
-                    .set(VAR3, "new3")
-                    .unset(VAR1)
-                    .unset(VAR3);
-                assert_eq!(std::env::var_os(VAR1), None);
-                assert_eq!(std::env::var_os(VAR2), Some("new2".into()));
-                assert_eq!(std::env::var_os(VAR3), None);
-            }
-            assert_eq!(std::env::var_os(VAR1), Some("old1".into()));
-            assert_eq!(std::env::var_os(VAR2), Some("old2".into()));
-            assert_eq!(std::env::var_os(VAR3), None);
-        }
-    }
 }

tests/tools/tests/env.rs

@@ -0,0 +1,93 @@
+use std::env;
+
+use gix_testtools::Env;
+use serial_test::serial;
+
+// We rely on these not already existing, to test `Env` without using or rewriting it.
+static VAR1: &str = "VAR_03FC4045_6043_4A61_9D15_852236CB632B";
+static VAR2: &str = "VAR_8C135840_05DB_4F3A_BFDD_FC755EC35B89";
+static VAR3: &str = "VAR_9B23A2BE_E20B_4670_93E2_3A6A8D47F274";
+
+struct TestEnv;
+
+impl TestEnv {
+    fn new() -> Self {
+        assert_eq!(env::var_os(VAR1), None);
+        assert_eq!(env::var_os(VAR2), None);
+        assert_eq!(env::var_os(VAR3), None);
+        Self
+    }
+}
+
+impl Drop for TestEnv {
+    fn drop(&mut self) {
+        env::remove_var(VAR1);
+        env::remove_var(VAR2);
+        env::remove_var(VAR3);
+    }
+}
+
+#[test]
+#[serial]
+fn nonoverlapping() {
+    let _meta = TestEnv::new();
+    env::set_var(VAR1, "old1");
+    env::set_var(VAR2, "old2");
+    {
+        let _env = Env::new().set(VAR1, "new1").unset(VAR2).set(VAR3, "new3");
+        assert_eq!(env::var_os(VAR1), Some("new1".into()));
+        assert_eq!(env::var_os(VAR2), None);
+        assert_eq!(env::var_os(VAR3), Some("new3".into()));
+    }
+    assert_eq!(env::var_os(VAR1), Some("old1".into()));
+    assert_eq!(env::var_os(VAR2), Some("old2".into()));
+    assert_eq!(env::var_os(VAR3), None);
+}
+
+#[test]
+#[serial]
+fn overlapping_reset() {
+    let _meta = TestEnv::new();
+    {
+        let _env = Env::new().set(VAR1, "new1A").set(VAR1, "new1B");
+        assert_eq!(env::var_os(VAR1), Some("new1B".into()));
+    }
+    assert_eq!(env::var_os(VAR1), None);
+}
+
+#[test]
+#[serial]
+fn overlapping_unset() {
+    let _meta = TestEnv::new();
+    env::set_var(VAR1, "old1");
+    {
+        let _env = Env::new().unset(VAR1).unset(VAR1);
+        assert_eq!(env::var_os(VAR1), None);
+    }
+    assert_eq!(env::var_os(VAR1), Some("old1".into()));
+}
+
+#[test]
+#[serial]
+fn overlapping_combo() {
+    let _meta = TestEnv::new();
+    env::set_var(VAR1, "old1");
+    env::set_var(VAR2, "old2");
+    {
+        let _env = Env::new()
+            .set(VAR1, "new1A")
+            .unset(VAR2)
+            .set(VAR1, "new1B")
+            .unset(VAR3)
+            .set(VAR2, "new2")
+            .set(VAR3, "new3")
+            .unset(VAR1)
+            .unset(VAR3);
+        assert_eq!(env::var_os(VAR1), None);
+        assert_eq!(env::var_os(VAR2), Some("new2".into()));
+        assert_eq!(env::var_os(VAR3), None);
+    }
+    assert_eq!(env::var_os(VAR1), Some("old1".into()));
+    assert_eq!(env::var_os(VAR2), Some("old2".into()));
+    assert_eq!(env::var_os(VAR3), None);
+}