Put functional tests in `tests/functional`

I think it is bad for these reasons when `tests/` contains a mix of
functional and integration tests

 - Concepts is harder to understand, the documentation makes a good
   unit vs functional vs integration distinction, but when the
   integration tests are just two subdirs within `tests/` this is not
   clear.

 - Source filtering in the `flake.nix` is more complex. We need to
   filter out some of the dirs from `tests/`, rather than simply pick
   the dirs we want and take all of them. This is a good sign the
   structure of what we are trying to do is not matching the structure
   of the files.

With this change we have a clean:
```shell-session
$ git show 'HEAD:tests'
tree HEAD:tests

functional/
installer/
nixos/
```

(cherry picked from commit 68c81c737571794f7246db53fb4774e94fcf4b7e)

1 files changed, 53 insertions, 0 deletions

diff --git a/tests/functional/restricted.sh b/tests/functional/restricted.sh
new file mode 100644
index 000000000..197ae7a10
--- /dev/null
+++ b/tests/functional/restricted.sh
@@ -0,0 +1,53 @@
+source common.sh
+
+clearStore
+
+nix-instantiate --restrict-eval --eval -E '1 + 2'
+(! nix-instantiate --eval --restrict-eval ./restricted.nix)
+(! nix-instantiate --eval --restrict-eval <(echo '1 + 2'))
+nix-instantiate --restrict-eval ./simple.nix -I src=.
+nix-instantiate --restrict-eval ./simple.nix -I src1=simple.nix -I src2=config.nix -I src3=./simple.builder.sh
+
+(! nix-instantiate --restrict-eval --eval -E 'builtins.readFile ./simple.nix')
+nix-instantiate --restrict-eval --eval -E 'builtins.readFile ./simple.nix' -I src=../..
+
+(! nix-instantiate --restrict-eval --eval -E 'builtins.readDir ../../src/nix-channel')
+nix-instantiate --restrict-eval --eval -E 'builtins.readDir ../../src/nix-channel' -I src=../../src
+
+(! nix-instantiate --restrict-eval --eval -E 'let __nixPath = [ { prefix = "foo"; path = ./.; } ]; in <foo>')
+nix-instantiate --restrict-eval --eval -E 'let __nixPath = [ { prefix = "foo"; path = ./.; } ]; in <foo>' -I src=.
+
+p=$(nix eval --raw --expr "builtins.fetchurl file://$(pwd)/restricted.sh" --impure --restrict-eval --allowed-uris "file://$(pwd)")
+cmp $p restricted.sh
+
+(! nix eval --raw --expr "builtins.fetchurl file://$(pwd)/restricted.sh" --impure --restrict-eval)
+
+(! nix eval --raw --expr "builtins.fetchurl file://$(pwd)/restricted.sh" --impure --restrict-eval --allowed-uris "file://$(pwd)/restricted.sh/")
+
+nix eval --raw --expr "builtins.fetchurl file://$(pwd)/restricted.sh" --impure --restrict-eval --allowed-uris "file://$(pwd)/restricted.sh"
+
+(! nix eval --raw --expr "builtins.fetchurl https://github.com/NixOS/patchelf/archive/master.tar.gz" --impure --restrict-eval)
+(! nix eval --raw --expr "builtins.fetchTarball https://github.com/NixOS/patchelf/archive/master.tar.gz" --impure --restrict-eval)
+(! nix eval --raw --expr "fetchGit git://github.com/NixOS/patchelf.git" --impure --restrict-eval)
+
+ln -sfn $(pwd)/restricted.nix $TEST_ROOT/restricted.nix
+[[ $(nix-instantiate --eval $TEST_ROOT/restricted.nix) == 3 ]]
+(! nix-instantiate --eval --restrict-eval $TEST_ROOT/restricted.nix)
+(! nix-instantiate --eval --restrict-eval $TEST_ROOT/restricted.nix -I $TEST_ROOT)
+(! nix-instantiate --eval --restrict-eval $TEST_ROOT/restricted.nix -I .)
+nix-instantiate --eval --restrict-eval $TEST_ROOT/restricted.nix -I $TEST_ROOT -I .
+
+[[ $(nix eval --raw --impure --restrict-eval -I . --expr 'builtins.readFile "${import ./simple.nix}/hello"') == 'Hello World!' ]]
+
+# Check whether we can leak symlink information through directory traversal.
+traverseDir="$(pwd)/restricted-traverse-me"
+ln -sfn "$(pwd)/restricted-secret" "$(pwd)/restricted-innocent"
+mkdir -p "$traverseDir"
+goUp="..$(echo "$traverseDir" | sed -e 's,[^/]\+,..,g')"
+output="$(nix eval --raw --restrict-eval -I "$traverseDir" \
+    --expr "builtins.readFile \"$traverseDir/$goUp$(pwd)/restricted-innocent\"" \
+    2>&1 || :)"
+echo "$output" | grep "is forbidden"
+echo "$output" | grepInverse -F restricted-secret
+
+expectStderr 1 nix-instantiate --restrict-eval true ./dependencies.nix | grepQuiet "forbidden in restricted mode"