tests/functional2: Migrate symlink-resolution

the newly added f1/lang tests is required for the f1/lang framework
dismanteling to happen in a separate commit

Change-Id: Ic419c515262294c51a46d1513daa7848e4b71405

tests/functional/lang/eval-okay-empty.exp

@@ -0,0 +1 @@
+""

tests/functional/lang/eval-okay-empty.nix

@@ -0,0 +1 @@
+""

tests/functional/lang/eval-okay-symlink-resolution.exp

@@ -1 +0,0 @@
-"test"

tests/functional/lang/eval-okay-symlink-resolution.nix

@@ -1 +0,0 @@
-import symlink-resolution/foo/overlays/overlay.nix

tests/functional2/eval/assets/symlink-resolution.out.exp

@@ -0,0 +1 @@
+"test"

tests/functional2/eval/test_symlink_resoultion.py

@@ -0,0 +1,22 @@
+from collections.abc import Callable
+from pathlib import Path
+
+from functional2.testlib.fixtures.file_helper import with_files, File, AssetSymlink, Symlink
+from functional2.testlib.fixtures.nix import Nix
+from functional2.testlib.fixtures.snapshot import Snapshot
+
+
+@with_files(
+    {
+        "in.nix": File("import symlink-resolution/foo/overlays/overlay.nix"),
+        "out.exp": AssetSymlink("assets/symlink-resolution.out.exp"),
+        "symlink-resolution": {
+            "foo": {"lib": {"default.nix": File('"test"')}, "overlays": Symlink("../overlays")},
+            "overlays": {"overlay.nix": File("import ../lib")},
+        },
+    }
+)
+def test_symlink_resolution(nix: Nix, files: Path, snapshot: Callable[[str], Snapshot]):
+    res = nix.nix_instantiate(["--eval", "--strict", files / "in.nix"]).run().ok()
+    assert snapshot("out.exp") == res.stdout_plain
+    assert not res.stderr_plain