Add test for fetchGit submodule support

tests/fetchGitSubmodules.sh

@@ -0,0 +1,50 @@
+source common.sh
+
+set -u
+
+if [[ -z $(type -p git) ]]; then
+    echo "Git not installed; skipping Git submodule tests"
+    exit 99
+fi
+
+clearStore
+
+rootRepo=$TEST_ROOT/gitSubmodulesRoot
+subRepo=$TEST_ROOT/gitSubmodulesSub
+
+rm -rf ${rootRepo} ${subRepo} $TEST_HOME/.cache/nix/gitv2
+
+initGitRepo() {
+    git init $1
+    git -C $1 config user.email "foobar@example.com"
+    git -C $1 config user.name "Foobar"
+}
+
+addGitContent() {
+    echo "lorem ipsum" > $1/content
+    git -C $1 add content
+    git -C $1 commit -m "Initial commit"
+}
+
+initGitRepo $subRepo
+addGitContent $subRepo
+
+initGitRepo $rootRepo
+
+git -C $rootRepo submodule init
+git -C $rootRepo submodule add $subRepo sub
+git -C $rootRepo add sub
+git -C $rootRepo commit -m "Add submodule"
+
+rev=$(git -C $rootRepo rev-parse HEAD)
+
+pathWithoutSubmodules=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; rev = \"$rev\"; }).outPath")
+pathWithSubmodules=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; rev = \"$rev\"; fetchSubmodules = true; }).outPath")
+
+# The resulting store path cannot be the same.
+[[ $pathWithoutSubmodules != $pathWithSubmodules ]]
+
+[[ ! -e $pathWithoutSubmodules/sub/content ]]
+[[ -e $pathWithSubmodules/sub/content ]]
+
+

tests/local.mk

@@ -17,6 +17,7 @@ nix_tests = \
   nar-access.sh \
   structured-attrs.sh \
   fetchGit.sh \
+  fetchGitSubmodules.sh \
   fetchMercurial.sh \
   signing.sh \
   run.sh \