fix(hooks): use same branchless dir for all worktrees

Previously, all worktrees would have their own event log, which means that they wouldn't agree on the set of visible commits. They would also have to recalculate the same DAG, etc. After this commit, they all share the same event log, etc.

Author: arxanas

git-branchless-hook/tests/test_hook.rs

@@ -1,4 +1,4 @@
-use lib::testing::{make_git, GitRunOptions};
+use lib::testing::{make_git, make_git_worktree, GitRunOptions, GitWorktreeWrapper};
 
 #[test]
 fn test_is_rebase_underway() -> eyre::Result<()> {
@@ -148,3 +148,81 @@ fn test_rebase_no_process_new_commits_until_conclusion() -> eyre::Result<()> {
 
     Ok(())
 }
+
+#[test]
+fn test_hooks_in_worktree() -> eyre::Result<()> {
+    let git = make_git()?;
+    git.init_repo()?;
+    git.commit_file("test1", 1)?;
+    git.detach_head()?;
+
+    let GitWorktreeWrapper {
+        temp_dir: _temp_dir,
+        worktree,
+    } = make_git_worktree(&git, "new-worktree")?;
+
+    {
+        let (stdout, stderr) =
+            worktree.run(&["commit", "--allow-empty", "-m", "new empty commit"])?;
+        insta::assert_snapshot!(stderr, @r###"
+        branchless: processing 1 update: ref HEAD
+        branchless: processed commit: 1bed0d8 new empty commit
+        "###);
+        insta::assert_snapshot!(stdout, @r###"
+        [detached HEAD 1bed0d8] new empty commit
+        "###);
+    }
+
+    {
+        let stdout = git.smartlog()?;
+        insta::assert_snapshot!(stdout, @r###"
+        :
+        @ 62fc20d (master) create test1.txt
+        |
+        o 1bed0d8 new empty commit
+        "###);
+    }
+    {
+        let stdout = worktree.smartlog()?;
+        insta::assert_snapshot!(stdout, @r###"
+        :
+        O 62fc20d (master) create test1.txt
+        |
+        @ 1bed0d8 new empty commit
+        "###);
+    }
+
+    {
+        let (stdout, stderr) =
+            worktree.run(&["commit", "--amend", "--allow-empty", "--message", "amended"])?;
+        insta::assert_snapshot!(stderr, @r###"
+        branchless: processing 1 update: ref HEAD
+        branchless: processed commit: cc4313e amended
+        branchless: processing 1 rewritten commit
+        "###);
+        insta::assert_snapshot!(stdout, @r###"
+        [detached HEAD cc4313e] amended
+         Date: Thu Oct 29 12:34:56 2020 +0000
+        "###);
+    }
+    {
+        let stdout = git.smartlog()?;
+        insta::assert_snapshot!(stdout, @r###"
+        :
+        @ 62fc20d (master) create test1.txt
+        |
+        o cc4313e amended
+        "###);
+    }
+    {
+        let stdout = worktree.smartlog()?;
+        insta::assert_snapshot!(stdout, @r###"
+        :
+        O 62fc20d (master) create test1.txt
+        |
+        @ cc4313e amended
+        "###);
+    }
+
+    Ok(())
+}