Add baseline tests for tree-merges.

That way, Git can indicate what we need to match.

Author: Byron

gix-merge/tests/fixtures/tree-baseline.sh

@@ -0,0 +1,70 @@
+#!/usr/bin/env bash
+set -eu -o pipefail
+
+function tick () {
+  if test -z "${tick+set}"
+  then
+    tick=1112911993
+  else
+    tick=$(($tick + 60))
+  fi
+  GIT_COMMITTER_DATE="$tick -0700"
+  GIT_AUTHOR_DATE="$tick -0700"
+  export GIT_COMMITTER_DATE GIT_AUTHOR_DATE
+}
+
+function write_lines () {
+	printf "%s\n" "$@"
+}
+
+git init simple
+(cd simple
+  rm -Rf .git/hooks
+  write_lines 1 2 3 4 5 >numbers
+  echo hello >greeting
+  echo foo >whatever
+  git add numbers greeting whatever
+  tick
+  git commit -m initial
+
+  git branch side1
+  git branch side2
+  git branch side3
+  git branch side4
+
+  git checkout side1
+  write_lines 1 2 3 4 5 6 >numbers
+  echo hi >greeting
+  echo bar >whatever
+  git add numbers greeting whatever
+  tick
+  git commit -m modify-stuff
+
+  git checkout side2
+  write_lines 0 1 2 3 4 5 >numbers
+  echo yo >greeting
+  git rm whatever
+  mkdir whatever
+  >whatever/empty
+  git add numbers greeting whatever/empty
+  tick
+  git commit -m other-modifications
+
+  git checkout side3
+  git mv numbers sequence
+  tick
+  git commit -m rename-numbers
+
+  git checkout side4
+  write_lines 0 1 2 3 4 5 >numbers
+  echo yo >greeting
+  git add numbers greeting
+  tick
+  git commit -m other-content-modifications
+
+  git switch --orphan unrelated
+  >something-else
+  git add something-else
+  tick
+  git commit -m first-commit
+)