From 9478f886810b8db87b7ebfe14343f77159c86a24 Mon Sep 17 00:00:00 2001
From: Samuel Dionne-Riel <samuel@dionne-riel.com>
Date: Sun, 8 Apr 2018 00:45:28 -0400
Subject: [PATCH] Adds `nix-shell` test for special-cased ruby interpreter.

The test fakes the interpreter only to verify the arguments it would be
given.
---
 tests/nix-shell.sh     | 9 +++++++++
 tests/shell.nix        | 7 +++++++
 tests/shell.shebang.rb | 7 +++++++
 3 files changed, 23 insertions(+)
 create mode 100644 tests/shell.shebang.rb

diff --git a/tests/nix-shell.sh b/tests/nix-shell.sh
index 063e97ce..7f14b6c3 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 5845d36f..eb39f903 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 00000000..ea3953ae
--- /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.")