feat(tvix/tests): check in Nix' language test suite r/4461

This adds scaffolding code for running the Nix language test suite.

The majority of eval-okay-* tests should eventually be runnable as-is
by Tvix, however the eval-fail-* tests might not as we intend to have
more useful error messages than upstream Nix.

Change-Id: I4f3227f0889c55e4274b804a3072850fb78dd1bd
Reviewed-on: https://cl.tvl.fyi/c/depot/+/6126
Tested-by: BuildkiteCI
Autosubmit: tazjin <tazjin@tvl.su>
Reviewed-by: grfn <grfn@gws.fyi>

1 files changed, 13 insertions, 0 deletions

diff --git a/tvix/eval/src/tests/nix_tests/eval-okay-tojson.nix b/tvix/eval/src/tests/nix_tests/eval-okay-tojson.nix
new file mode 100644
index 000000000000..ce67943bead5
--- /dev/null
+++ b/tvix/eval/src/tests/nix_tests/eval-okay-tojson.nix
@@ -0,0 +1,13 @@
+builtins.toJSON
+  { a = 123;
+    b = -456;
+    c = "foo";
+    d = "foo\n\"bar\"";
+    e = true;
+    f = false;
+    g = [ 1 2 3 ];
+    h = [ "a" [ "b" { "foo\nbar" = {}; } ] ];
+    i = 1 + 2;
+    j = 1.44;
+    k = { __toString = self: self.a; a = "foo"; };
+  }