2 files changed, 98 insertions, 0 deletions
diff --git a/tests/fetchGitSubmodules.sh b/tests/fetchGitSubmodules.sh
new file mode 100644
index 000000000..4c2c13f1a
--- /dev/null
+++ b/tests/fetchGitSubmodules.sh
@@ -0,0 +1,97 @@
+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
+
+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 $rootRepo rev-parse HEAD)
+
+r1=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; rev = \"$rev\"; }).outPath")
+r2=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; rev = \"$rev\"; submodules = false; }).outPath")
+r3=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; rev = \"$rev\"; submodules = true; }).outPath")
+
+[[ $r1 == $r2 ]]
+[[ $r2 != $r3 ]]
+
+r4=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; ref = \"master\"; rev = \"$rev\"; }).outPath")
+r5=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; ref = \"master\"; rev = \"$rev\"; submodules = false; }).outPath")
+r6=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; ref = \"master\"; rev = \"$rev\"; submodules = true; }).outPath")
+r7=$(nix eval --raw "(builtins.fetchGit { url = $rootRepo; ref = \"master\"; rev = \"$rev\"; submodules = true; }).outPath")
+r8=$(nix eval --raw "(builtins.fetchGit { url = $rootRepo; rev = \"$rev\"; submodules = true; }).outPath")
+
+[[ $r1 == $r4 ]]
+[[ $r4 == $r5 ]]
+[[ $r3 == $r6 ]]
+[[ $r6 == $r7 ]]
+[[ $r7 == $r8 ]]
+
+have_submodules=$(nix eval "(builtins.fetchGit { url = $rootRepo; rev = \"$rev\"; }).submodules")
+[[ $have_submodules == false ]]
+
+have_submodules=$(nix eval "(builtins.fetchGit { url = $rootRepo; rev = \"$rev\"; submodules = false; }).submodules")
+[[ $have_submodules == false ]]
+
+have_submodules=$(nix eval "(builtins.fetchGit { url = $rootRepo; rev = \"$rev\"; submodules = true; }).submodules")
+[[ $have_submodules == true ]]
+
+pathWithoutSubmodules=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; rev = \"$rev\"; }).outPath")
+pathWithSubmodules=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; rev = \"$rev\"; submodules = true; }).outPath")
+pathWithSubmodulesAgain=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; rev = \"$rev\"; submodules = true; }).outPath")
+pathWithSubmodulesAgainWithRef=$(nix eval --raw "(builtins.fetchGit { url = file://$rootRepo; ref = \"master\"; rev = \"$rev\"; submodules = true; }).outPath")
+
+# The resulting store path cannot be the same.
+[[ $pathWithoutSubmodules != $pathWithSubmodules ]]
+
+# Checking out the same repo with submodules returns in the same store path.
+[[ $pathWithSubmodules == $pathWithSubmodulesAgain ]]
+
+# Checking out the same repo with submodules returns in the same store path.
+[[ $pathWithSubmodulesAgain == $pathWithSubmodulesAgainWithRef ]]
+
+# The submodules flag is actually honored.
+[[ ! -e $pathWithoutSubmodules/sub/content ]]
+[[ -e $pathWithSubmodules/sub/content ]]
+
+[[ -e $pathWithSubmodulesAgainWithRef/sub/content ]]
+
+# No .git directory or submodule reference files must be left
+test "$(find "$pathWithSubmodules" -name .git)" = ""
+
+# Git repos without submodules can be fetched with submodules = true.
+subRev=$(git -C $subRepo rev-parse HEAD)
+noSubmoduleRepoBaseline=$(nix eval --raw "(builtins.fetchGit { url = file://$subRepo; rev = \"$subRev\"; }).outPath")
+noSubmoduleRepo=$(nix eval --raw "(builtins.fetchGit { url = file://$subRepo; rev = \"$subRev\"; submodules = true; }).outPath")
+
+[[ $noSubmoduleRepoBaseline == $noSubmoduleRepo ]]
diff --git a/tests/local.mk b/tests/local.mk
index dab3a23b6..01fac4fcd 100644
--- a/tests/local.mk
+++ b/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 \