git-preview: init

1 files changed, 17 insertions, 0 deletions

diff --git a/krebs/5pkgs/simple/git-preview.nix b/krebs/5pkgs/simple/git-preview.nix
new file mode 100644
index 00000000..d6c9579a
--- /dev/null
+++ b/krebs/5pkgs/simple/git-preview.nix
@@ -0,0 +1,17 @@
+{ coreutils, git, writeDashBin }:
+
+writeDashBin "git-preview" ''
+  set -efu
+  head_commit=$(${git}/bin/git log -1 --format=%H)
+  merge_commit=$1; shift
+  merge_message='Merge for git-preview'
+  preview_dir=$(${coreutils}/bin/mktemp --tmpdir -d git-preview.XXXXXXXX)
+  preview_branch=$(${coreutils}/bin/basename "$preview_dir")
+  ${git}/bin/git worktree add -b "$preview_branch" "$preview_dir" >/dev/null
+  ${git}/bin/git -C "$preview_dir" checkout "$head_commit"
+  ${git}/bin/git -C "$preview_dir" merge -m "$merge_message" "$merge_commit"
+  ${git}/bin/git -C "$preview_dir" diff "$head_commit.." "$@" &
+  ${git}/bin/git branch -fd "$preview_branch"
+  ${coreutils}/bin/rm -fR "$preview_dir"
+  wait
+''