From 7a04fb1c56ca60652c2a44019b31fe8cf2e2bc46 Mon Sep 17 00:00:00 2001
From: Tom Bereknyei <tomberek@gmail.com>
Date: Fri, 20 May 2022 08:20:00 -0400
Subject: [PATCH] repl: add repl-flake experimental feature for gating

---
 src/libutil/experimental-features.cc | 1 +
 src/libutil/experimental-features.hh | 1 +
 src/nix/repl.cc                      | 2 +-
 tests/repl.sh                        | 6 +++---
 4 files changed, 6 insertions(+), 4 deletions(-)

diff --git a/src/libutil/experimental-features.cc b/src/libutil/experimental-features.cc
index 315de64a4..fa79cca6b 100644
--- a/src/libutil/experimental-features.cc
+++ b/src/libutil/experimental-features.cc
@@ -13,6 +13,7 @@ std::map<ExperimentalFeature, std::string> stringifiedXpFeatures = {
     { Xp::RecursiveNix, "recursive-nix" },
     { Xp::NoUrlLiterals, "no-url-literals" },
     { Xp::FetchClosure, "fetch-closure" },
+    { Xp::ReplFlake, "repl-flake" },
 };
 
 const std::optional<ExperimentalFeature> parseExperimentalFeature(const std::string_view & name)
diff --git a/src/libutil/experimental-features.hh b/src/libutil/experimental-features.hh
index 57512830c..d09ab025c 100644
--- a/src/libutil/experimental-features.hh
+++ b/src/libutil/experimental-features.hh
@@ -22,6 +22,7 @@ enum struct ExperimentalFeature
     RecursiveNix,
     NoUrlLiterals,
     FetchClosure,
+    ReplFlake,
 };
 
 /**
diff --git a/src/nix/repl.cc b/src/nix/repl.cc
index e9898c08c..b12f05c15 100644
--- a/src/nix/repl.cc
+++ b/src/nix/repl.cc
@@ -897,7 +897,7 @@ struct CmdRepl : InstallablesCommand
     }
     void prepare()
     {
-        if (!settings.isExperimentalFeatureEnabled(Xp::Flakes) && !(file) && this->_installables.size() >= 1) {
+        if (!settings.isExperimentalFeatureEnabled(Xp::ReplFlake) && !(file) && this->_installables.size() >= 1) {
             warn("future versions of Nix will require using `--file` to load a file");
             if (this->_installables.size() > 1)
                 warn("more than one input file is not currently supported");
diff --git a/tests/repl.sh b/tests/repl.sh
index 07f647585..5caf0a58a 100644
--- a/tests/repl.sh
+++ b/tests/repl.sh
@@ -87,7 +87,7 @@ drvPath
 testReplResponse '
 drvPath
 ' '".*-simple.drv"' \
---file $testDir/simple.nix --experimental-features 'flakes'
+--file $testDir/simple.nix --experimental-features 'repl-flake'
 
 mkdir -p flake && cat <<EOF > flake/flake.nix
 {
@@ -102,7 +102,7 @@ EOF
 testReplResponse '
 foo + baz
 ' "3" \
-    ./flake ./flake\#bar
+    ./flake ./flake\#bar --experimental-features 'flakes repl-flake'
 
 # Test the `:reload` mechansim with flakes:
 # - Eval `./flake#changingThing`
@@ -115,6 +115,6 @@ sleep 1 # Leave the repl the time to eval 'foo'
 sed -i 's/beforeChange/afterChange/' flake/flake.nix
 echo ":reload"
 echo "changingThing"
-) | nix repl ./flake)
+) | nix repl ./flake --experimental-features 'flakes repl-flake')
 echo "$replResult" | grep -qs beforeChange
 echo "$replResult" | grep -qs afterChange