fix: fix multiple issues by adding break as first cmd to git-rebase-todo and --continueing after launching rebase

Signed-off-by: Kipras Melnikovas <kipras@kipras.org>

Author: kiprasmel

git-stacked-rebase.ts

@@ -91,6 +91,115 @@ function areOptionsIncompetible(
 	return reasons.length > 0;
 }
 
+/**
+ * some notes:
+ *
+ * 1. re: "the different ways to launch git rebase":
+ *
+ * 1.1 initially, we started probably the hardest way:
+ *     we tried to replicate the behavior of git rebase, by:
+ *
+ * 1) finding which commits we need (manually by ourselves),
+ * 2) letting the user edit our own git-rebase-todo file
+ *    (already containing branch boundaries generated by us),
+ * 3) creating & writing to files inside `.git/rebase-{merge|apply}/`,
+ *    just like git rebase would, to represent the current state [1].
+ * 4) and then exec'ing a `git rebase --continue`,
+ *    so that the user gets launched into the rebase.
+ *
+ *
+ * 1.2 later, we started using 2 rebases - 1st for finding the commits, 2nd for the actual rebase.
+ *
+ * important switch that i didn't think had significance until 1.3 --
+ * using `editorScript`s (providing an env var - a string of a path to a bash script
+ * that will move the user-edited & our-processed git-rebase-todo file
+ * into the proper place (.git/rebase-{merge|apply}/git-rebase-todo)
+ * right when the rebase starts, thus no longer having to `--continue` (!),
+ * which is what broke things that were discovered
+ * and fixed in 1.3 by (fabricately) introducing `--continue` back)
+ *
+ *
+ * 1.3 but soon after, things started breaking.
+ *
+ * i didn't understand why.
+ *
+ * but after playing w/ it for a while, realized that it's stuff like `reword`
+ * that breaks, as long as  we launch the rebase with an `editorScript`.
+ * e.g. git would ask to identify yourself - config wouldn't be detected,
+ * and our `--apply` was completely broken as well [2].
+ *
+ * thus we started manually adding a first command `break`
+ * into the proper `git-rebase-todo` file [3]
+ * so that we can launch `--continue` again,
+ * after the `editorScript` had finished,
+ * and that somehow fixed everything & we're back to normal.
+ *
+ *
+ *
+ * i am still not sure what the best approach is,
+ * though i think i know which one's aren't.
+ *
+ * 1.1 seems bad because imitating the full behavior is hard,
+ *
+ * e.g. respecting commit.gpgSign required creating a file `gpg_sign_opt`
+ * with content `-S` - there's probably a ton of stuff like this i didn't even realize
+ * that git has, and it's possible more will be added in the future.
+ * you can obviously see the problems that stem from this.
+ *
+ * 1.2 seems bad because it, apart from being broken until 1.3,
+ * also used 2 rebases instead of 1, and that is kinda hacky.
+ * stuff like git hooks exists, e.g. post-write,
+ * that even we ourselves utilize,
+ * and launching 2 rebases means producing side-effects
+ * like this, and we're potentially breaking end users' workflows.
+ *
+ * thus, 1.3 seems like a clear winner, at least for now.
+ * especially up until we investigate the break + continue thingie -
+ * ideally we wouldn't need it.
+ *
+ *
+ *
+ * ---
+ *
+ * [1]
+ * on representing the _state_ -- git rebase,
+ * specifically the --interactive one (which is what we have here as well),
+ * is _not_ a continuous command that goes through and is 100% done when it exits.
+ *
+ * there are some cases where it intentionally exits, to allow the user
+ * to do further interactions, and later --continue the rebase
+ * (e.g. `edit`, `break` etc.).
+ *
+ * thus, some state needs to be saved, so that the user, once they're done,
+ * can tell git to --continue.
+ *
+ * turns out, git does this very simply - by saving files inside `.git/`,
+ * and `.git/rebase-{merge|apply}/` folders.
+ * this simple design is a big part in allowing tools like us,
+ * git-stacked-rebase, to work, or rather - to expand upon the existing stuff,
+ * w/o having to re-implement everything ourselves.
+ *
+ * [2]
+ * on the --apply being broken - it's the logic of `parseNewGoodCommands` that seems broken.
+ *
+ * right before realizing 1.3 and writing this comment,
+ * i wrote a lengthy comment there as well, with thoughts of what's likely broken.
+ *
+ * but now, after discovering 1.3, i do not understand yet how the
+ * `--continue` exec fixes things, and am not sure if i want to mess
+ * with the `parseNewGoodCommands` logic before i do.
+ *
+ * [3]
+ * the user would never see the `break` command, since just like in 1.1 2),
+ * we give the user to edit our own git-rebase-todo file, which contains branch boundaries,
+ * and then extracting the normal git rebase commands and creating
+ * the git-rebase-todo file for git rebase to run on.
+ *
+ * ---
+ *
+ *
+ *
+ */
 export const gitStackedRebase = async (
 	nameOfInitialBranch: string,
 	specifiedOptions: SomeOptionsForGitStackedRebase = {}
@@ -305,6 +414,11 @@ export const gitStackedRebase = async (
 		// let lastCommitFromEditedTodo;
 		const regularRebaseTodoLines: string[] = [];
 
+		/**
+		 * part 1 of "the different ways to launch git rebase"
+		 */
+		regularRebaseTodoLines.push("break");
+
 		const goodCommands: GoodCommand[] = parseTodoOfStackedRebase(pathToStackedRebaseTodoFile);
 
 		const proms: Promise<void>[] = goodCommands.map(async (cmd) => {
@@ -600,6 +714,11 @@ mv -f "${preparedRegularRebaseTodoFile}" "${pathToRegularRebaseTodoFile}"
 		);
 		log("big buns - 2nd rebase returned (the proper one)");
 
+		/**
+		 * part 2 of "the different ways to launch git rebase"
+		 */
+		execSyncInRepo(`${options.gitCmd} rebase --continue`);
+
 		/** END COPY-PASTA */
 
 		/**