exchange_test.v

1//! Two-machine tests: two repos and one folder remote standing in for the Mac2//! and the PC. This is where offer, steal and combine are actually proven —3//! the folder backend exists so these run offline.45module exchange67import os8import src.events9import src.history10import src.remote11import src.snapshot12import src.storage1314// Machines keep their repo in a folder of the same NAME, because the remote key15// is the folder's name; that is what makes them the same repo to the remote.16fn machine(name string) !string {17	dir := os.join_path(os.temp_dir(), 'koh3_sync_${os.getpid()}_${name}', 'proj')18	os.rmdir_all(os.dir(dir)) or {}19	os.mkdir_all(dir, os.MkdirParams{})!20	return dir21}2223fn scratch(name string) !string {24	dir := os.join_path(os.temp_dir(), 'koh3_sync_${os.getpid()}_${name}')25	os.rmdir_all(dir) or {}26	os.mkdir_all(dir, os.MkdirParams{})!27	return dir28}2930fn open_repo(dir string) !storage.Store {31	mut store := storage.create(dir)!32	os.write_file(os.join_path(dir, '.kohignore'), '*.log\n')!33	return store34}3536fn put(root string, rel string, text string) ! {37	full := os.join_path(root, rel)38	os.mkdir_all(os.dir(full), os.MkdirParams{})!39	os.write_file(full, text)!40}4142fn make_save(store &storage.Store, message string) !history.Save {43	return history.save_worktree(store, store.root, snapshot.load(store.root), history.SaveInput{44		message: message45	})!46}4748fn offer_now(store &storage.Store, mut backend remote.Backend) !OfferReport {49	return offer(store, mut backend)!50}5152fn steal_now(store &storage.Store, mut backend remote.Backend) !StealReport {53	return steal(store, mut backend, StealOptions{54		theirs: true55	})!56}5758fn test_first_offer_publishes_the_whole_line() {59	base := scratch('first')!60	defer {61		os.rmdir_all(base) or {}62	}63	mut a := open_repo(machine('first_a')!)!64	defer {65		a.close()66	}67	put(a.root, 'a.txt', 'one\n')!68	make_save(a, 'first')!69	put(a.root, 'a.txt', 'two\n')!70	make_save(a, 'second')!71	mut backend := remote.new_folder(os.join_path(base, 'remote'))!7273	report := offer_now(a, mut backend)!74	assert report.repo == 'proj'75	assert report.saves == 276	assert report.objects >= 277	assert backend.get(head_key('proj'))!.found78	assert backend.list('proj/saves')!.len == 27980	// A second offer with nothing new uploads nothing and still succeeds.81	again := offer_now(a, mut backend)!82	assert again.saves == 083}8485fn test_the_repo_name_is_remembered_and_head_offered() {86	base := scratch('remember')!87	defer {88		os.rmdir_all(base) or {}89	}90	mut a := open_repo(machine('remember_a')!)!91	defer {92		a.close()93	}94	put(a.root, 'a.txt', 'one\n')!95	make_save(a, 'first')!96	mut backend := remote.new_folder(os.join_path(base, 'remote'))!97	offer_now(a, mut backend)!98	assert a.state('remote_repo') or { '' } == 'proj'99	assert backend.get(head_key('proj'))!.body.bytestr() == head_of(a).id100	// Offer's step 3: the new remote head is recorded in state.101	assert a.state('remote_head') or { '' } == head_of(a).id102103	// A second offer, with the remote already holding our head, must not104	// refuse: the name is remembered, so the remote is ours.105	put(a.root, 'a.txt', 'two\n')!106	make_save(a, 'second')!107	offer_now(a, mut backend)!108	assert backend.get(head_key('proj'))!.body.bytestr() == head_of(a).id109}110111fn test_steal_fast_forwards_a_machine_that_has_nothing_of_its_own() {112	base := scratch('forward')!113	defer {114		os.rmdir_all(base) or {}115	}116	mut backend := remote.new_folder(os.join_path(base, 'remote'))!117	mut a := open_repo(machine('fwd_a')!)!118	defer {119		a.close()120	}121	put(a.root, 'a.txt', 'from A\n')!122	make_save(a, 'A writes')!123	offer_now(a, mut backend)!124125	// B starts empty and pulls the whole repo.126	mut b := open_repo(machine('fwd_b')!)!127	defer {128		b.close()129	}130	fetched := fetch_repo(mut backend, 'proj')!131	b.begin()!132	write_fetched(b, fetched)!133	history.set_head(b, fetched.head)!134	b.commit()!135	snapshot.restore_files(b, b.root, snapshot.load(b.root), history.files_of(b, fetched.head)!, [])!136	assert os.read_file(os.join_path(b.root, 'a.txt'))! == 'from A\n'137	assert head_of(b).id == fetched.head138}139140// A machine that is only ahead has nothing to combine: stealing must leave its141// saves, and their IDs, exactly where they are.142fn test_steal_while_only_ahead_leaves_the_line_alone() {143	base := scratch('ahead')!144	defer {145		os.rmdir_all(base) or {}146	}147	mut backend := remote.new_folder(os.join_path(base, 'remote'))!148	mut a := open_repo(machine('ahead_a')!)!149	defer {150		a.close()151	}152	put(a.root, 'a.txt', 'one\n')!153	make_save(a, 'offered')!154	offer_now(a, mut backend)!155	put(a.root, 'a.txt', 'two\n')!156	ahead := make_save(a, 'not offered yet')!157	report := steal_now(a, mut backend)!158	assert report.replayed == 0159	assert head_of(a).id == ahead.id160	// Nothing was restored, so nothing is left marked as half-restored.161	assert !snapshot.restore_pending(a)162	assert history.all_saves(a)!.len == 2163	offer_now(a, mut backend)!164	assert backend.get(head_key('proj'))!.body.bytestr() == ahead.id165}166167// A link is invisible to the walk, so a tree holding one is clean; the files168// a steal brings in must still never land in the folder it points at.169fn test_steal_never_writes_through_a_symlinked_folder() {170	base := scratch('steal_link')!171	defer {172		os.rmdir_all(base) or {}173	}174	mut backend := remote.new_folder(os.join_path(base, 'remote'))!175	mut a := open_repo(machine('steal_link_a')!)!176	defer {177		a.close()178	}179	mut b := open_repo(machine('steal_link_b')!)!180	defer {181		b.close()182	}183	put(a.root, 'a.txt', 'one\n')!184	make_save(a, 'first')!185	offer_now(a, mut backend)!186	join(b, mut backend)!187	outside := os.join_path(base, 'outside')188	put(outside, 'a.md', 'precious\n')!189	os.symlink(outside, os.join_path(b.root, 'docs'))!190	put(a.root, 'docs/a.md', 'from A\n')!191	make_save(a, 'A adds docs')!192	offer_now(a, mut backend)!193	head_before := head_of(b).id194	if _ := steal_now(b, mut backend) {195		assert false, 'a steal writing through a symlinked folder must refuse'196	} else {197		assert err.msg().contains('docs')198	}199	assert os.read_file(os.join_path(outside, 'a.md'))! == 'precious\n'200	assert head_of(b).id == head_before201}202203// A steal onto a half-restored tree would replay it as somebody's work.204fn test_steal_refuses_after_a_restore_cut_short() {205	base := scratch('steal_cut')!206	defer {207		os.rmdir_all(base) or {}208	}209	mut backend := remote.new_folder(os.join_path(base, 'remote'))!210	mut a := open_repo(machine('steal_cut_a')!)!211	defer {212		a.close()213	}214	put(a.root, 'a.txt', 'one\n')!215	make_save(a, 'first')!216	offer_now(a, mut backend)!217	a.set_state('restoring', 'yes')!218	if _ := steal_now(a, mut backend) {219		assert false, 'steal must refuse while a restore is unfinished'220	} else {221		assert err.msg().contains('koh revert')222	}223}224225// A replayed save keeps its original time but sits on a newer parent, so a226// clone cannot order saves by time.227fn test_a_clone_imports_parents_before_children() {228	base := scratch('clone_order')!229	defer {230		os.rmdir_all(base) or {}231	}232	mut backend := remote.new_folder(os.join_path(base, 'remote'))!233	mut a := open_repo(machine('order_a')!)!234	defer {235		a.close()236	}237	put(a.root, 'a.txt', 'one\n')!238	parent := make_save(a, 'parent')!239	child := history.save_tree(a, '', history.files_of(a, parent.id)!, history.SaveInput{240		message:    'replayed, older than its parent'241		created_at: parent.created_at - 3600242	})!243	offer_now(a, mut backend)!244	mut b := open_repo(machine('order_b')!)!245	defer {246		b.close()247	}248	join(b, mut backend)!249	assert head_of(b).id == child.id250}251252// A chmod is unsaved work too: a steal would restore the old mode over it.253fn test_steal_refuses_an_unsaved_executable_bit_change() {254	base := scratch('chmod')!255	defer {256		os.rmdir_all(base) or {}257	}258	mut backend := remote.new_folder(os.join_path(base, 'remote'))!259	mut a := open_repo(machine('chmod_a')!)!260	defer {261		a.close()262	}263	put(a.root, 'run.sh', 'echo hi\n')!264	make_save(a, 'script')!265	offer_now(a, mut backend)!266	os.chmod(os.join_path(a.root, 'run.sh'), 0o755)!267	if _ := steal_now(a, mut backend) {268		assert false, 'a chmod-only change should make the tree dirty'269	} else {270		assert err.msg() == dirty_tree271	}272}273274fn test_divergence_without_clashes_keeps_both_machines_work() {275	base := scratch('diverge')!276	defer {277		os.rmdir_all(base) or {}278	}279	mut backend := remote.new_folder(os.join_path(base, 'remote'))!280	mut a := open_repo(machine('div_a')!)!281	defer {282		a.close()283	}284	mut b := open_repo(machine('div_b')!)!285	defer {286		b.close()287	}288	put(a.root, 'shared.txt', 'base\n')!289	make_save(a, 'base')!290	offer_now(a, mut backend)!291292	// B joins, then both machines change a different file.293	join(b, mut backend)!294	put(a.root, 'fromA.txt', 'A\n')!295	make_save(a, 'A adds a file')!296	put(b.root, 'fromB.txt', 'B\n')!297	make_save(b, 'B adds a file')!298	offer_now(a, mut backend)!299300	// B's offer is refused: the remote has moved on.301	if _ := offer_now(b, mut backend) {302		assert false, 'offering on top of unknown remote saves should be refused'303	} else {304		assert err.msg().contains('run koh steal')305	}306307	report := steal_now(b, mut backend)!308	assert !report.forward309	assert report.replayed == 1310	assert report.clashes.len == 0311	// Both files are on B's line now, and on disk.312	assert os.read_file(os.join_path(b.root, 'fromA.txt'))! == 'A\n'313	assert os.read_file(os.join_path(b.root, 'fromB.txt'))! == 'B\n'314	assert os.read_file(os.join_path(b.root, 'shared.txt'))! == 'base\n'315	// B's own save was replayed, not erased.316	mut saw_replay := false317	for save in history.all_saves(b)! {318		if save.replayed_from != '' {319			saw_replay = true320		}321	}322	assert saw_replay323	// And the remote now has B's work too.324	offer_now(b, mut backend)!325	line_head := backend.get(head_key('proj'))!.body.bytestr().trim_space()326	assert line_head == head_of(b).id327}328329// An agent that edits a file and then undoes the edit leaves no net change, so330// the file is not a clash when the other machine changed it. Replaying the331// edit itself must not stop the steal: the remote's version simply stands.332// Likewise a file both machines ended up changing the same way.333fn test_a_local_change_undone_does_not_block_a_combine() {334	base := scratch('undone')!335	defer {336		os.rmdir_all(base) or {}337	}338	mut backend := remote.new_folder(os.join_path(base, 'remote'))!339	mut a := open_repo(machine('undone_a')!)!340	defer {341		a.close()342	}343	mut b := open_repo(machine('undone_b')!)!344	defer {345		b.close()346	}347	put(a.root, 'f.txt', 'base\n')!348	put(a.root, 'g.txt', 'base\n')!349	make_save(a, 'base')!350	offer_now(a, mut backend)!351	join(b, mut backend)!352353	put(a.root, 'f.txt', 'from A\n')!354	put(a.root, 'g.txt', 'same\n')!355	make_save(a, 'A edits both')!356	offer_now(a, mut backend)!357358	put(b.root, 'f.txt', 'tried on B\n')!359	put(b.root, 'g.txt', 'first try\n')!360	tried := make_save(b, 'B tries')!361	put(b.root, 'f.txt', 'base\n')!362	put(b.root, 'g.txt', 'same\n')!363	put(b.root, 'h.txt', 'B\n')!364	undone := make_save(b, 'B undoes f, lands on the same g, adds h')!365366	report := steal_now(b, mut backend)!367	assert report.clashes.len == 0368	assert os.read_file(os.join_path(b.root, 'f.txt'))! == 'from A\n'369	assert os.read_file(os.join_path(b.root, 'g.txt'))! == 'same\n'370	assert os.read_file(os.join_path(b.root, 'h.txt'))! == 'B\n'371	// "B tries" only touched files A changed, so it has nothing left to372	// replay; the second save carries h.txt. Both originals stay in history.373	assert report.replayed == 1374	assert head_of(b).replayed_from == undone.id375	ids := history.all_saves(b)!.map(it.id)376	assert tried.id in ids && undone.id in ids377	assert history.files_of(b, tried.id)!.any(it.path == 'f.txt')378}379380// A person deciding a clash may take minutes; the question must come before381// the write lock, or every agent's save on this repo waits and then fails.382fn test_clash_questions_are_asked_before_the_write_lock() {383	base := scratch('ask_unlocked')!384	defer {385		os.rmdir_all(base) or {}386	}387	mut backend := remote.new_folder(os.join_path(base, 'remote'))!388	mut a := open_repo(machine('ask_a')!)!389	defer {390		a.close()391	}392	mut b := open_repo(machine('ask_b')!)!393	defer {394		b.close()395	}396	put(a.root, 'same.txt', 'base\n')!397	make_save(a, 'base')!398	offer_now(a, mut backend)!399	join(b, mut backend)!400	put(a.root, 'same.txt', 'A version\n')!401	make_save(a, 'A edits same')!402	offer_now(a, mut backend)!403	put(b.root, 'same.txt', 'B version\n')!404	make_save(b, 'B edits same')!405	root := b.root406	// An agent saves while the person is still choosing.407	if _ := steal(b, mut backend, StealOptions{408		ask: fn [root] (clash Clash) Side {409			other := storage.open(root) or { panic(err) }410			defer {411				other.close()412			}413			os.write_file(os.join_path(root, 'agent.txt'), 'saved meanwhile\n') or { panic(err) }414			history.save_worktree(other, root, snapshot.load(root), history.SaveInput{415				message: 'agent saves during the question'416			}) or { panic('steal held the write lock while asking: ${err}') }417			return .mine418		}419	})420	{421		assert false, 'a steal whose line moved during the question must refuse'422	} else {423		assert err.msg().contains('changed while')424	}425	// The agent's save is still head, and a second steal combines it too.426	assert head_of(b).message == 'agent saves during the question'427	report := steal(b, mut backend, StealOptions{428		mine: true429	})!430	assert report.kept_mine == 1431	assert os.read_file(os.join_path(b.root, 'agent.txt'))! == 'saved meanwhile\n'432	assert os.read_file(os.join_path(b.root, 'same.txt'))! == 'B version\n'433}434435fn test_clashing_files_are_chosen_one_at_a_time() {436	base := scratch('clash')!437	defer {438		os.rmdir_all(base) or {}439	}440	mut backend := remote.new_folder(os.join_path(base, 'remote'))!441	mut a := open_repo(machine('clash_a')!)!442	defer {443		a.close()444	}445	mut b := open_repo(machine('clash_b')!)!446	defer {447		b.close()448	}449	put(a.root, 'same.txt', 'base\n')!450	put(a.root, 'other.txt', 'quiet\n')!451	make_save(a, 'base')!452	offer_now(a, mut backend)!453	join(b, mut backend)!454455	// Both machines edit the same file, differently.456	put(a.root, 'same.txt', 'A version\n')!457	make_save(a, 'A edits same')!458	offer_now(a, mut backend)!459	put(b.root, 'same.txt', 'B version\n')!460	make_save(b, 'B edits same')!461462	// Without a decision, steal refuses and says which files clash.463	if _ := steal(b, mut backend, StealOptions{}) {464		assert false, 'an undecided clash must be refused'465	} else {466		assert err.msg().contains('--mine') || err.msg().contains('--theirs')467		// `koh offer` has no --mine or --theirs, so it needs the paths, not this sentence.468		if err is ClashError {469			assert err.paths == ['same.txt']470		} else {471			assert false, 'an undecided clash must be a ClashError, not ${err}'472		}473	}474	assert find_clashes(history.files_of(b, head_of(b).id)!, history.files_of(b, head_of(b).id)!, history.files_of(b,475		head_of(b).id)!).len == 0476477	// Choosing the remote's version ends with A's content.478	report := steal_now(b, mut backend)!479	assert report.clashes == ['same.txt']480	assert report.kept_mine == 0481	assert report.kept_versions == ['same.txt:${report.previous_head}']482	assert os.read_file(os.join_path(b.root, 'same.txt'))! == 'A version\n'483	assert os.read_file(os.join_path(b.root, 'other.txt'))! == 'quiet\n'484}485486fn test_cancelling_a_guided_steal_keeps_the_line_and_can_retry() {487	base := scratch('guided_cancel')!488	defer { os.rmdir_all(base) or {} }489	mut backend := remote.new_folder(os.join_path(base, 'remote'))!490	mut a := open_repo(machine('guided_cancel_a')!)!491	defer { a.close() }492	mut b := open_repo(machine('guided_cancel_b')!)!493	defer { b.close() }494	put(a.root, 'same.txt', 'base\n')!495	make_save(a, 'base')!496	offer_now(a, mut backend)!497	join(b, mut backend)!498	put(a.root, 'same.txt', 'remote\n')!499	remote_head := make_save(a, 'remote change')!500	offer_now(a, mut backend)!501	put(b.root, 'same.txt', 'mine\n')!502	local_head := make_save(b, 'local change')!503504	if _ := steal(b, mut backend, StealOptions{505		guide: fn (preview StealPreview) !map[string]Side {506			assert preview.clashes.len == 1507			return error('cancelled')508		}509	}) {510		assert false, 'the guide cancelled'511	} else {512		assert err.msg() == 'cancelled'513	}514	assert head_of(b).id == local_head.id515	assert os.read_file(os.join_path(b.root, 'same.txt'))! == 'mine\n'516	assert history.by_id(b, remote_head.id) != none517	assert steal(b, mut backend, StealOptions{ mine: true })!.kept_mine == 1518}519520fn test_choosing_mine_keeps_the_local_version() {521	base := scratch('mine')!522	defer {523		os.rmdir_all(base) or {}524	}525	mut backend := remote.new_folder(os.join_path(base, 'remote'))!526	mut a := open_repo(machine('mine_a')!)!527	defer {528		a.close()529	}530	mut b := open_repo(machine('mine_b')!)!531	defer {532		b.close()533	}534	put(a.root, 'same.txt', 'base\n')!535	make_save(a, 'base')!536	offer_now(a, mut backend)!537	join(b, mut backend)!538	put(a.root, 'same.txt', 'A version\n')!539	make_save(a, 'A edits')!540	offer_now(a, mut backend)!541	put(b.root, 'same.txt', 'B version\n')!542	make_save(b, 'B edits')!543544	report := steal(b, mut backend, StealOptions{545		mine: true546	})!547	assert report.kept_mine == 1548	assert os.read_file(os.join_path(b.root, 'same.txt'))! == 'B version\n'549	// The final save says what it kept.550	assert head_of(b).message.contains('combine: kept mine for 1 file')551	// The pre-combine tree is still reachable in history.552	assert head_of(b).restores == ''553	assert history.all_saves(b)!.len >= 4554}555556fn test_flags_travel_with_the_saves() {557	base := scratch('flags')!558	defer {559		os.rmdir_all(base) or {}560	}561	mut backend := remote.new_folder(os.join_path(base, 'remote'))!562	mut a := open_repo(machine('flag_a')!)!563	defer {564		a.close()565	}566	mut b := open_repo(machine('flag_b')!)!567	defer {568		b.close()569	}570	put(a.root, 'a.txt', 'one\n')!571	save := make_save(a, 'suspect save')!572	events.flag(a, save.id, 'look at this')!573	offer_now(a, mut backend)!574575	// B has nothing yet, so a fetch brings the save and its flag across.576	fetched := fetch_back_to_known(b, mut backend, 'proj')!577	assert fetched.events_out.len == 1578	assert fetched.events_out[0].kind == events.kind_flag579	b.begin()!580	write_fetched(b, fetched)!581	history.set_head(b, fetched.head)!582	b.commit()!583	state := events.flag_state(b, save.id)!584	assert state.flagged585	assert state.reason == 'look at this'586}587588fn test_a_second_offer_racing_head_is_refused_not_forced() {589	base := scratch('race')!590	defer {591		os.rmdir_all(base) or {}592	}593	mut backend := remote.new_folder(os.join_path(base, 'remote'))!594	mut a := open_repo(machine('race_a')!)!595	defer {596		a.close()597	}598	put(a.root, 'a.txt', 'one\n')!599	make_save(a, 'base')!600	offer_now(a, mut backend)!601602	// Someone else replaces head behind our back.603	assert backend.put_if_match(head_key('proj'), 'a-save-we-do-not-have'.bytes(),604		backend.get(head_key('proj'))!.tag)!605606	put(a.root, 'a.txt', 'two\n')!607	make_save(a, 'second')!608	if _ := offer_now(a, mut backend) {609		assert false, 'offering while the remote head moved must be refused'610	} else {611		assert err.msg().contains('run koh steal')612	}613}614615// join makes a brand new machine share the remote's line.616fn join(store &storage.Store, mut backend remote.Backend) ! {617	fetched := fetch_repo(mut backend, 'proj')!618	store.begin()!619	write_fetched(store, fetched)!620	history.set_head(store, fetched.head)!621	store.commit()!622	snapshot.restore_files(store, store.root, snapshot.load(store.root), history.files_of(store,623		fetched.head)!, [])!624	store.set_state('remote_repo', 'proj')!625}626627struct FaultyBackend {628mut:629	inner      remote.Backend630	writes     int631	reads      int632	fail_write int // fail when the write counter reaches this, 0 never633	fail_read  int634	// fail every delete while set635	fail_delete bool636	// race_format stands in for another machine writing the format key first:637	// the first `format` write loses, to a value this koh does not speak.638	race_format bool639	raced       bool640}641642fn (mut f FaultyBackend) get(key string) !remote.Object {643	f.reads++644	if f.fail_read > 0 && f.reads >= f.fail_read {645		return error('injected read failure')646	}647	return f.inner.get(key)!648}649650fn (mut f FaultyBackend) list(prefix string) ![]string {651	return f.inner.list(prefix)!652}653654fn (mut f FaultyBackend) put_if_absent(key string, body []u8) !bool {655	f.writes++656	if f.fail_write > 0 && f.writes >= f.fail_write {657		return error('injected write failure')658	}659	if f.race_format && !f.raced && key.ends_with('/format') {660		f.raced = true661		f.inner.put_if_absent(key, 'koh-remote 2'.bytes())!662		return false663	}664	return f.inner.put_if_absent(key, body)!665}666667fn (mut f FaultyBackend) put_if_match(key string, body []u8, tag string) !bool {668	f.writes++669	if f.fail_write > 0 && f.writes >= f.fail_write {670		return error('injected write failure')671	}672	return f.inner.put_if_match(key, body, tag)!673}674675fn (mut f FaultyBackend) delete(key string) ! {676	if f.fail_delete {677		return error('injected delete failure')678	}679	f.inner.delete(key)!680}681682// Every save offers after it is made, so a one-file change must cost one683// object, not one conditional write per file in the repo: on S3 each of those684// is a round trip.685fn test_an_offer_sends_only_the_objects_a_save_adds() {686	base := scratch('offer_diff')!687	defer {688		os.rmdir_all(base) or {}689	}690	mut a := open_repo(machine('offer_diff_a')!)!691	defer {692		a.close()693	}694	for i in 0 .. 20 {695		put(a.root, 'f${i}.txt', 'file ${i}\n')!696	}697	make_save(a, 'twenty files')!698	mut backend := FaultyBackend{699		inner: remote.new_folder(os.join_path(base, 'remote'))!700	}701	offer(a, mut backend)!702	put(a.root, 'f3.txt', 'changed\n')!703	make_save(a, 'one change')!704	before := backend.writes705	report := offer(a, mut backend)!706	assert report.objects == 1707	// One object, one save record, one head swap.708	assert backend.writes - before == 3709}710711fn test_a_failed_offer_is_safe_to_re_run() {712	base := scratch('fault_offer')!713	defer {714		os.rmdir_all(base) or {}715	}716	remote_dir := os.join_path(base, 'remote')717	mut a := open_repo(machine('fault_a')!)!718	defer {719		a.close()720	}721	put(a.root, 'a.txt', 'one\n')!722	make_save(a, 'first')!723	put(a.root, 'a.txt', 'two\n')!724	make_save(a, 'second')!725726	// The first offer dies after the first write.727	mut flaky := FaultyBackend{728		inner:      remote.new_folder(remote_dir)!729		fail_write: 2730	}731	if _ := offer(a, mut flaky) {732		assert false, 'the injected failure should have surfaced'733	}734735	// Re-running with a healthy remote finishes the job: "already exists" is736	// success, so nothing is lost and nothing is duplicated.737	mut healthy := remote.new_folder(remote_dir)!738	report := offer(a, mut healthy)!739	assert report.saves == 2740	assert healthy.get(head_key('proj'))!.body.bytestr().trim_space() == head_of(a).id741	assert healthy.list('proj/saves')!.len == 2742}743744fn test_a_failed_steal_leaves_nothing_behind() {745	base := scratch('fault_steal')!746	defer {747		os.rmdir_all(base) or {}748	}749	remote_dir := os.join_path(base, 'remote')750	mut a := open_repo(machine('fault_s_a')!)!751	defer {752		a.close()753	}754	mut b := open_repo(machine('fault_s_b')!)!755	defer {756		b.close()757	}758	put(a.root, 'a.txt', 'from A\n')!759	make_save(a, 'A writes')!760	mut healthy := remote.new_folder(remote_dir)!761	offer(a, mut healthy)!762763	// B's fetch fails half way through reading the remote.764	mut flaky := FaultyBackend{765		inner:     remote.new_folder(remote_dir)!766		fail_read: 2767	}768	if _ := fetch_back_to_known(b, mut flaky, 'proj') {769		assert false, 'the injected read failure should have surfaced'770	}771	// Nothing was written: the store is untouched and still has no saves.772	assert history.head(b) == none773	assert b.object_count()! == 0774775	// A healthy retry works.776	fetched := fetch_back_to_known(b, mut healthy, 'proj')!777	b.begin()!778	write_fetched(b, fetched)!779	history.set_head(b, fetched.head)!780	b.commit()!781	snapshot.restore_files(b, b.root, snapshot.load(b.root), history.files_of(b, fetched.head)!, [])!782	assert os.read_file(os.join_path(b.root, 'a.txt'))! == 'from A\n'783}784785fn test_an_interrupted_strip_is_idempotent() {786	// The local half of a strip is one transaction, so an interrupted strip is787	// simply a strip that did not happen; re-running it must land the same788	// result once, not twice.789	base := scratch('fault_strip')!790	defer {791		os.rmdir_all(base) or {}792	}793	mut a := open_repo(machine('fault_strip_a')!)!794	defer {795		a.close()796	}797	put(a.root, 'secret.txt', 'shh\n')!798	put(a.root, 'keep.txt', 'fine\n')!799	save := make_save(a, 'add both')!800801	for _ in 0 .. 2 {802		strip_local(a, 'secret.txt', '')!803	}804	files := history.files_of(a, save.id)!805	// The repo's own `.kohignore` is tracked content, so it stays; only the806	// stripped path goes.807	assert files.map(it.path) == ['.kohignore', 'keep.txt']808	assert events.strip_events(a)!.len == 1809}810811// SQLite's LIKE ignores ASCII case, so a strip of `docs` must not reach into812// `Docs/`, and `a_b` must not reach `aXb`: strip destroys, so it matches exactly.813// The tree is built by hand: on macOS `Docs` and `docs` are one folder on disk,814// but a save made on Linux can hold both.815fn test_a_strip_matches_the_path_exactly() {816	mut a := open_repo(machine('strip_exact')!)!817	defer {818		a.close()819	}820	hash := a.put_object('x\n'.bytes())!821	mut files := []snapshot.FileEntry{}822	for path in ['DOCS.txt', 'Docs/keep.txt', 'a_b/x.txt', 'aXb/y.txt', 'docs/secret.txt'] {823		files << snapshot.FileEntry{824			path: path825			hash: hash826		}827	}828	save := history.save_tree(a, '', files, history.SaveInput{829		message: 'add all'830	})!831	assert strip_scope(a, 'docs', '')!.files == 1832	strip_local(a, 'docs', '')!833	strip_local(a, 'a_b', '')!834	assert history.files_of(a, save.id)!.map(it.path) == ['DOCS.txt', 'Docs/keep.txt', 'aXb/y.txt']835}836837fn test_a_strip_reaches_the_remote_and_other_machines() {838	base := scratch('strip_sync')!839	defer {840		os.rmdir_all(base) or {}841	}842	mut a := open_repo(machine('strip_a')!)!843	defer {844		a.close()845	}846	mut b := open_repo(machine('strip_b')!)!847	defer {848		b.close()849	}850	put(a.root, 'secrets.env', 'api_key=1\n')!851	put(a.root, 'keep.txt', 'fine\n')!852	save := make_save(a, 'add both')!853	mut backend := remote.new_folder(os.join_path(base, 'remote'))!854	offer_now(a, mut backend)!855	join(b, mut backend)!856	assert b.object_count()! > 0857858	// A strips the path locally, the way `koh strip` does, then tells the859	// remote.860	mut secret_hash := ''861	for file in history.files_of(a, save.id)! {862		if file.path == 'secrets.env' {863			secret_hash = file.hash864		}865	}866	assert secret_hash != ''867	strip_local(a, 'secrets.env', '')!868	report := push_strip(a, mut backend, 'secrets.env')!869	assert report.event_sent870	assert report.records == 1871872	// The remote's copy of the save no longer lists the file, and the object is873	// gone from the remote.874	record := decode_save(backend.get(save_key('proj', save.id))!.body)!875	for file in record.files {876		assert file.path != 'secrets.env'877	}878	// The stripped object is gone from the remote; the ones still referenced879	// are not.880	assert !backend.get(object_key('proj', secret_hash))!.found881	assert backend.list('proj/objects')!.len == 2882883	// Another machine hears about it on its next steal and applies it.884	b.begin()!885	fetched := fetch_back_to_known(b, mut backend, 'proj')!886	write_fetched(b, fetched)!887	b.commit()!888	mut paths := []string{}889	for file in history.files_of(b, save.id)! {890		paths << file.path891	}892	assert 'secrets.env' !in paths893	assert 'keep.txt' in paths894895	// The event arrives under its own ID, so it is applied once: B's offer adds896	// no second copy, and a file B saves again after the strip stays saved897	// through B's next steal.898	assert events.strip_events(b)!.map(it.id) == events.strip_events(a)!.map(it.id)899	put(b.root, 'secrets.env', 'rotated\n')!900	readded := make_save(b, 'add the rotated key back')!901	offer_now(b, mut backend)!902	assert backend.list('proj/events')!.len == 1903	b.begin()!904	write_fetched(b, fetch_back_to_known(b, mut backend, 'proj')!)!905	b.commit()!906	assert 'secrets.env' in history.files_of(b, readded.id)!.map(it.path)907}908909// A strip removes a path from the saves that existed when it was made. A key910// rotated and saved again afterwards is new work: a machine that clones the911// repo later must get it, not strip it on arrival.912fn test_a_clone_keeps_a_file_saved_again_after_a_strip() {913	base := scratch('strip_clone')!914	defer {915		os.rmdir_all(base) or {}916	}917	mut backend := remote.new_folder(os.join_path(base, 'remote'))!918	mut a := open_repo(machine('strip_clone_a')!)!919	defer {920		a.close()921	}922	put(a.root, 'secrets.env', 'api_key=1\n')!923	old := make_save(a, 'leak the key')!924	offer_now(a, mut backend)!925	strip_local(a, 'secrets.env', '')!926	push_strip(a, mut backend, 'secrets.env')!927	// Saves after the strip must be later in time, as they would be for real.928	put(a.root, 'secrets.env', 'api_key=2\n')!929	rotated := history.save_tree(a, a.root, snapshot.walk(a, a.root, snapshot.load(a.root))!, history.SaveInput{930		message:    'rotate the key'931		created_at: events.strip_events(a)!.last().created_at + 60932	})!933	offer_now(a, mut backend)!934935	mut c := open_repo(machine('strip_clone_c')!)!936	defer {937		c.close()938	}939	join(c, mut backend)!940	assert 'secrets.env' in history.files_of(c, rotated.id)!.map(it.path)941	assert 'secrets.env' !in history.files_of(c, old.id)!.map(it.path)942	assert os.read_file(os.join_path(c.root, 'secrets.env'))! == 'api_key=2\n'943}944945// The local half commits before the remote hears anything, so a remote failure946// leaves nothing to find locally; the pending note is what lets a re-run947// finish. Objects a remote-only save still needs must survive the strip.948fn test_an_interrupted_remote_strip_finishes_when_re_run() {949	base := scratch('strip_resume')!950	defer {951		os.rmdir_all(base) or {}952	}953	remote_dir := os.join_path(base, 'remote')954	mut backend := remote.new_folder(remote_dir)!955	mut a := open_repo(machine('resume_a')!)!956	defer {957		a.close()958	}959	mut b := open_repo(machine('resume_b')!)!960	defer {961		b.close()962	}963	put(a.root, 'secrets.env', 'api_key=1\n')!964	put(a.root, 'shared.env', 'same bytes on B\n')!965	save := make_save(a, 'add secrets')!966	offer_now(a, mut backend)!967	join(b, mut backend)!968	put(b.root, 'copy.txt', 'same bytes on B\n')!969	b_save := make_save(b, 'B keeps a copy')!970	offer_now(b, mut backend)!971	shared_hash := storage.hash_hex('same bytes on B\n'.bytes())972	secret_hash := storage.hash_hex('api_key=1\n'.bytes())973974	strip_local(a, 'secrets.env', '')!975	// Write 1 uploads the event and write 2 rewrites the first record; B's save,976	// made from A's tree, lists the file too, and its rewrite (write 3) fails.977	mut flaky := FaultyBackend{978		inner:      remote.new_folder(remote_dir)!979		fail_write: 3980	}981	if _ := push_strip(a, mut flaky, 'secrets.env') {982		assert false, 'the injected failure should have surfaced'983	}984	assert strip_pending(a, 'secrets.env')985	assert strip_local(a, 'secrets.env', '')!.files_removed == 0986	report := push_strip(a, mut backend, 'secrets.env')!987	assert report.records == 1988	assert !strip_pending(a, 'secrets.env')989	assert !backend.get(object_key('proj', secret_hash))!.found990	record := decode_save(backend.get(save_key('proj', save.id))!.body)!991	assert 'secrets.env' !in record.files.map(it.path)992	b_record := decode_save(backend.get(save_key('proj', b_save.id))!.body)!993	assert 'secrets.env' !in b_record.files.map(it.path)994995	// B's save still names the shared bytes, so stripping A's copy keeps them.996	strip_local(a, 'shared.env', '')!997	push_strip(a, mut backend, 'shared.env')!998	assert backend.get(object_key('proj', shared_hash))!.found999}10001001// A machine that has not heard of a strip must not offer: its records still1002// list the stripped path, and nothing would rewrite them on the remote again.1003fn test_offer_waits_for_an_unapplied_strip() {1004	base := scratch('strip_first')!1005	defer {1006		os.rmdir_all(base) or {}1007	}1008	mut backend := remote.new_folder(os.join_path(base, 'remote'))!1009	mut a := open_repo(machine('strip_first_a')!)!1010	defer {1011		a.close()1012	}1013	mut b := open_repo(machine('strip_first_b')!)!1014	defer {1015		b.close()1016	}1017	put(a.root, 'secrets.env', 'api_key=1\n')!1018	make_save(a, 'add secrets')!1019	offer_now(a, mut backend)!1020	join(b, mut backend)!1021	strip_local(a, 'secrets.env', '')!1022	push_strip(a, mut backend, 'secrets.env')!1023	put(b.root, 'more.txt', 'B keeps working\n')!1024	later := make_save(b, 'B saves with the secret still in its tree')!1025	if _ := offer_now(b, mut backend) {1026		assert false, 'B offered records that still list the stripped path'1027	}1028	steal_now(b, mut backend)!1029	offer_now(b, mut backend)!1030	record := decode_save(backend.get(save_key('proj', later.id))!.body)!1031	assert 'secrets.env' !in record.files.map(it.path)1032}10331034// A strip whose object deletions failed, followed by a second strip of the same1035// path, must still delete the first strip's objects when it finishes.1036fn test_a_second_strip_keeps_the_first_ones_unfinished_objects() {1037	base := scratch('strip_twice')!1038	defer {1039		os.rmdir_all(base) or {}1040	}1041	remote_dir := os.join_path(base, 'remote')1042	mut backend := remote.new_folder(remote_dir)!1043	mut a := open_repo(machine('strip_twice_a')!)!1044	defer {1045		a.close()1046	}1047	put(a.root, 'secrets.env', 'first key\n')!1048	make_save(a, 'first key')!1049	offer_now(a, mut backend)!1050	strip_local(a, 'secrets.env', '')!1051	mut flaky := FaultyBackend{1052		inner:       remote.new_folder(remote_dir)!1053		fail_delete: true1054	}1055	if _ := push_strip(a, mut flaky, 'secrets.env') {1056		assert false, 'the injected delete failure should have surfaced'1057	}1058	put(a.root, 'secrets.env', 'second key\n')!1059	make_save(a, 'second key')!1060	offer_now(a, mut backend)!1061	strip_local(a, 'secrets.env', '')!1062	push_strip(a, mut backend, 'secrets.env')!1063	for key in ['first key\n', 'second key\n'] {1064		assert !backend.get(object_key('proj', storage.hash_hex(key.bytes())))!.found1065	}1066}10671068// Unfinished strips of one path in different scopes finish together.1069fn test_unfinished_strips_of_one_path_in_different_saves_finish_together() {1070	base := scratch('strip_scopes')!1071	defer {1072		os.rmdir_all(base) or {}1073	}1074	remote_dir := os.join_path(base, 'remote')1075	mut backend := remote.new_folder(remote_dir)!1076	mut a := open_repo(machine('strip_scopes_a')!)!1077	defer {1078		a.close()1079	}1080	put(a.root, 'secrets.env', 'first key\n')!1081	first := make_save(a, 'first key')!1082	put(a.root, 'secrets.env', 'second key\n')!1083	second := make_save(a, 'second key')!1084	offer_now(a, mut backend)!1085	strip_local(a, 'secrets.env', first.id)!1086	// Write 1 uploads the event; write 2, the record rewrite, fails.1087	mut flaky := FaultyBackend{1088		inner:      remote.new_folder(remote_dir)!1089		fail_write: 21090	}1091	if _ := push_strip(a, mut flaky, 'secrets.env') {1092		assert false, 'the injected failure should have surfaced'1093	}1094	strip_local(a, 'secrets.env', second.id)!1095	push_strip(a, mut backend, 'secrets.env')!1096	assert !strip_pending(a, 'secrets.env')1097	for save in [first, second] {1098		record := decode_save(backend.get(save_key('proj', save.id))!.body)!1099		assert 'secrets.env' !in record.files.map(it.path)1100	}1101	for key in ['first key\n', 'second key\n'] {1102		assert !backend.get(object_key('proj', storage.hash_hex(key.bytes())))!.found1103	}1104}11051106// Stripping a path, re-adding it, and stripping it again is two strips; a1107// machine that heard about the first must still apply the second.1108fn test_a_second_strip_of_the_same_path_reaches_other_machines() {1109	base := scratch('strip_again')!1110	defer {1111		os.rmdir_all(base) or {}1112	}1113	mut backend := remote.new_folder(os.join_path(base, 'remote'))!1114	mut a := open_repo(machine('strip_again_a')!)!1115	defer {1116		a.close()1117	}1118	mut b := open_repo(machine('strip_again_b')!)!1119	defer {1120		b.close()1121	}1122	put(a.root, 'secrets.env', 'first key\n')!1123	make_save(a, 'first key')!1124	offer_now(a, mut backend)!1125	join(b, mut backend)!1126	strip_local(a, 'secrets.env', '')!1127	push_strip(a, mut backend, 'secrets.env')!1128	steal_now(b, mut backend)!1129	// Strip leaves the file on disk; deleting it is the user's part.1130	os.rm(os.join_path(b.root, 'secrets.env'))!1131	put(a.root, 'secrets.env', 'second key\n')!1132	second := make_save(a, 'second key')!1133	offer_now(a, mut backend)!1134	steal_now(b, mut backend)!1135	assert 'secrets.env' in history.files_of(b, second.id)!.map(it.path)1136	strip_local(a, 'secrets.env', '')!1137	push_strip(a, mut backend, 'secrets.env')!1138	steal_now(b, mut backend)!1139	assert 'secrets.env' !in history.files_of(b, second.id)!.map(it.path)1140}11411142// A clash on a path the other machine stripped is no clash: the strip removes1143// the path from every save, so there is nothing to choose.1144fn test_a_stripped_path_is_not_asked_about() {1145	base := scratch('clash_strip')!1146	defer {1147		os.rmdir_all(base) or {}1148	}1149	mut backend := remote.new_folder(os.join_path(base, 'remote'))!1150	mut a := open_repo(machine('clash_strip_a')!)!1151	defer {1152		a.close()1153	}1154	mut b := open_repo(machine('clash_strip_b')!)!1155	defer {1156		b.close()1157	}1158	put(a.root, 'secrets.env', 'key one\n')!1159	make_save(a, 'base')!1160	offer_now(a, mut backend)!1161	join(b, mut backend)!1162	put(a.root, 'secrets.env', 'key two\n')!1163	make_save(a, 'A rotates')!1164	offer_now(a, mut backend)!1165	strip_local(a, 'secrets.env', '')!1166	push_strip(a, mut backend, 'secrets.env')!1167	put(b.root, 'secrets.env', 'key three\n')!1168	mine := make_save(b, 'B rotates')!1169	report := steal(b, mut backend, StealOptions{})!1170	assert report.clashes.len == 01171	for save in history.all_saves(b)! {1172		assert 'secrets.env' !in history.files_of(b, save.id)!.map(it.path)1173	}1174	assert history.by_id(b, mine.id) != none1175}11761177// A strip scoped to the shared base save changes what the replay sees; the1178// clashes must be found on the same trees, or the replay meets a conflict.1179fn test_a_strip_of_the_shared_base_is_seen_before_asking() {1180	base := scratch('clash_base_strip')!1181	defer {1182		os.rmdir_all(base) or {}1183	}1184	mut backend := remote.new_folder(os.join_path(base, 'remote'))!1185	mut a := open_repo(machine('base_strip_a')!)!1186	defer {1187		a.close()1188	}1189	mut b := open_repo(machine('base_strip_b')!)!1190	defer {1191		b.close()1192	}1193	put(a.root, 'notes.txt', 'shared\n')!1194	common := make_save(a, 'base')!1195	offer_now(a, mut backend)!1196	join(b, mut backend)!1197	put(a.root, 'other.txt', 'A moves on\n')!1198	make_save(a, 'A moves on')!1199	offer_now(a, mut backend)!1200	strip_local(a, 'notes.txt', common.id)!1201	push_strip(a, mut backend, 'notes.txt')!1202	put(b.root, 'notes.txt', 'B edits\n')!1203	make_save(b, 'B edits notes')!1204	if _ := steal(b, mut backend, StealOptions{}) {1205		assert false, 'with the base stripped, notes.txt differs on both sides'1206	} else {1207		assert err.msg().contains('notes.txt changed on both machines')1208	}1209	report := steal(b, mut backend, StealOptions{1210		mine: true1211	})!1212	assert report.clashes == ['notes.txt']1213	assert os.read_file(os.join_path(b.root, 'notes.txt'))! == 'B edits\n'1214}12151216// A folder with files but no saves has nothing to combine with; a steal that1217// fast-forwarded into it would overwrite whatever shares a name.1218fn test_steal_into_a_folder_with_unsaved_files_refuses() {1219	base := scratch('steal_unsaved')!1220	defer {1221		os.rmdir_all(base) or {}1222	}1223	mut backend := remote.new_folder(os.join_path(base, 'remote'))!1224	mut a := open_repo(machine('unsaved_a')!)!1225	defer {1226		a.close()1227	}1228	put(a.root, 'notes.txt', 'from A\n')!1229	make_save(a, 'A writes')!1230	offer_now(a, mut backend)!1231	b_root := machine('unsaved_b')!1232	mut b := storage.create(b_root)!1233	defer {1234		b.close()1235	}1236	put(b_root, 'notes.txt', 'never saved\n')!1237	// Only a repo that already knows its remote name gets this far.1238	b.set_state('remote_repo', 'proj')!1239	if _ := steal(b, mut backend, StealOptions{}) {1240		assert false, 'steal overwrote a folder with unsaved files'1241	} else {1242		assert err.msg() == no_saves_here1243	}1244	assert os.read_file(os.join_path(b_root, 'notes.txt'))! == 'never saved\n'1245	// A fresh `koh init` folder, holding only the default ignore list, is fine.1246	os.rm(os.join_path(b_root, 'notes.txt'))!1247	put(b_root, snapshot.ignore_file, snapshot.default_ignore)!1248	steal(b, mut backend, StealOptions{})!1249	assert os.read_file(os.join_path(b_root, 'notes.txt'))! == 'from A\n'1250}12511252// The document asks steal to warn about every incoming flagged save, so the1253// report names them.1254fn test_steal_reports_incoming_flagged_saves() {1255	base := scratch('flag_warn')!1256	defer {1257		os.rmdir_all(base) or {}1258	}1259	mut backend := remote.new_folder(os.join_path(base, 'remote'))!1260	mut a := open_repo(machine('flag_warn_a')!)!1261	defer {1262		a.close()1263	}1264	mut b := open_repo(machine('flag_warn_b')!)!1265	defer {1266		b.close()1267	}1268	put(a.root, 'a.txt', 'one\n')!1269	make_save(a, 'fine')!1270	offer_now(a, mut backend)!1271	join(b, mut backend)!1272	put(a.root, 'a.txt', 'two\n')!1273	suspect := make_save(a, 'suspect')!1274	put(a.root, 'a.txt', 'three\n')!1275	make_save(a, 'also fine')!1276	events.flag(a, suspect.id, 'broke the build')!1277	offer_now(a, mut backend)!1278	report := steal_now(b, mut backend)!1279	assert report.flagged.map(it.save_id) == [suspect.id]1280	assert report.flagged[0].reason == 'broke the build'1281}12821283// head_of unwraps the head for tests that know the repo has saves.1284fn head_of(store &storage.Store) history.Save {1285	return history.head(store) or { panic('this repo has no head') }1286}12871288// A remote says what it is, so two koh versions never half-understand one1289// bucket. The first offer of a repo records the layout.1290fn test_the_first_offer_records_the_remote_format() {1291	base := scratch('format_write')!1292	defer {1293		os.rmdir_all(base) or {}1294	}1295	mut backend := remote.new_folder(os.join_path(base, 'remote'))!1296	mut a := open_repo(machine('format_write_a')!)!1297	defer {1298		a.close()1299	}1300	put(a.root, 'a.txt', 'one\n')!1301	make_save(a, 'first')!1302	offer_now(a, mut backend)!1303	assert backend.get(format_key('proj'))!.body.bytestr().trim_space() == format_value1304}13051306// A repo offered before the key existed is version 1: it still syncs, and the1307// next offer records the key then.1308fn test_a_remote_without_a_format_still_syncs() {1309	base := scratch('format_old')!1310	defer {1311		os.rmdir_all(base) or {}1312	}1313	mut backend := remote.new_folder(os.join_path(base, 'remote'))!1314	mut a := open_repo(machine('format_old_a')!)!1315	defer {1316		a.close()1317	}1318	put(a.root, 'a.txt', 'one\n')!1319	make_save(a, 'first')!1320	offer_now(a, mut backend)!1321	// Stand in for a bucket offered before the key existed.1322	backend.delete(format_key('proj'))!1323	mut b := open_repo(machine('format_old_b')!)!1324	defer {1325		b.close()1326	}1327	join(b, mut backend)!1328	assert head_of(b).id == head_of(a).id1329	put(a.root, 'a.txt', 'two\n')!1330	make_save(a, 'second')!1331	offer_now(a, mut backend)!1332	assert backend.get(format_key('proj'))!.body.bytestr().trim_space() == format_value1333	report := steal_now(b, mut backend)!1334	assert report.head == head_of(a).id1335}13361337// A remote that speaks another layout is refused loudly, on offer and on1338// steal, rather than half-read.1339fn test_an_unknown_remote_format_is_refused() {1340	base := scratch('format_unknown')!1341	defer {1342		os.rmdir_all(base) or {}1343	}1344	mut backend := remote.new_folder(os.join_path(base, 'remote'))!1345	mut a := open_repo(machine('format_bad_a')!)!1346	defer {1347		a.close()1348	}1349	put(a.root, 'a.txt', 'one\n')!1350	make_save(a, 'first')!1351	offer_now(a, mut backend)!1352	backend.delete(format_key('proj'))!1353	backend.put_if_absent(format_key('proj'), 'koh-remote 2'.bytes())!1354	if _ := offer_now(a, mut backend) {1355		assert false, 'offer must refuse a format it does not speak'1356	} else {1357		assert err.msg().contains('koh-remote 2')1358	}1359	if _ := steal_now(a, mut backend) {1360		assert false, 'steal must refuse a format it does not speak'1361	} else {1362		assert err.msg().contains('koh-remote 2')1363	}1364	if _ := fetch_repo(mut backend, 'proj') {1365		assert false, 'a clone must refuse a format it does not speak'1366	} else {1367		assert err.msg().contains('koh-remote 2')1368	}1369}13701371// Two machines offering a new repo at once both find no format key; the loser1372// of the conditional write must read back the winner's value and refuse it,1373// not carry on against a remote it cannot read.1374fn test_a_lost_format_write_is_read_back_and_refused() {1375	base := scratch('format_race')!1376	defer {1377		os.rmdir_all(base) or {}1378	}1379	mut inner := remote.new_folder(os.join_path(base, 'remote'))!1380	mut a := open_repo(machine('format_race_a')!)!1381	defer {1382		a.close()1383	}1384	put(a.root, 'a.txt', 'one\n')!1385	make_save(a, 'first')!1386	mut backend := remote.Backend(FaultyBackend{1387		inner:       inner1388		race_format: true1389	})1390	if _ := offer_now(a, mut backend) {1391		assert false, 'offer must refuse the format another machine wrote first'1392	} else {1393		assert err.msg().contains('koh-remote 2')1394	}1395}