Adds `nix-shell` test for special-cased ruby interpreter.

The test fakes the interpreter only to verify the arguments it would be
given.

3 files changed, 23 insertions, 0 deletions

diff --git a/tests/nix-shell.sh b/tests/nix-shell.sh
index 063e97ce2c75..7f14b6c31db6 100644
--- a/tests/nix-shell.sh
+++ b/tests/nix-shell.sh
@@ -39,3 +39,12 @@ chmod a+rx $TEST_ROOT/shell.shebang.sh
 
 output=$($TEST_ROOT/shell.shebang.sh abc def)
 [ "$output" = "foo bar abc def" ]
+
+# Test nix-shell shebang mode for ruby
+# This uses a fake interpreter that returns the arguments passed
+# This, in turn, verifies the `rc` script is valid and the `load()` script (given using `-e`) is as expected.
+sed -e "s|@ENV_PROG@|$(type -p env)|" shell.shebang.rb > $TEST_ROOT/shell.shebang.rb
+chmod a+rx $TEST_ROOT/shell.shebang.rb
+
+output=$($TEST_ROOT/shell.shebang.rb abc ruby)
+[ "$output" = '-e load("'"$TEST_ROOT"'/shell.shebang.rb") -- abc ruby' ]
diff --git a/tests/shell.nix b/tests/shell.nix
index 5845d36fc161..eb39f9039a88 100644
--- a/tests/shell.nix
+++ b/tests/shell.nix
@@ -45,5 +45,12 @@ let pkgs = rec {
 
   bash = shell;
 
+  # ruby "interpreter" that outputs "$@"
+  ruby = runCommand "ruby" {} ''
+    mkdir -p $out/bin
+    echo 'printf -- "$*"' > $out/bin/ruby
+    chmod a+rx $out/bin/ruby
+  '';
+
   inherit pkgs;
 }; in pkgs
diff --git a/tests/shell.shebang.rb b/tests/shell.shebang.rb
new file mode 100644
index 000000000000..ea3953ae21ba
--- /dev/null
+++ b/tests/shell.shebang.rb
@@ -0,0 +1,7 @@
+#! @ENV_PROG@ nix-shell
+#! ruby
+#! nix-shell -I nixpkgs=shell.nix --no-substitute
+#! nix-shell --pure -p ruby -i ruby
+
+# Contents doesn't matter.
+abort("This shouldn't be executed.")