From c7d4f16d3e54f156c853cd61b080977a0815f01b Mon Sep 17 00:00:00 2001
From: Hojun-Cho <ghwns6743@gmail.com>
Date: Wed, 12 Aug 2026 16:16:25 +0900
Subject: [PATCH] test: stress engine transitions

---
 tests/engine_test.c | 114 ++++++++++++++++++++++++++++++++++++++++++++
 tests/test.h        |   1 +
 tests/unit_test.c   |   1 +
 3 files changed, 116 insertions(+)

diff --git a/tests/engine_test.c b/tests/engine_test.c
index f69a05b..246ae2f 100644
--- a/tests/engine_test.c
+++ b/tests/engine_test.c
@@ -1166,3 +1166,117 @@ engine_emoji_dictionary_identity(struct ct *t)
 	checkstr(t, "matching response accepted", "right", &im.kouho[0]);
 	emojiend(&f);
 }
+
+static u32int
+stressrand(u32int *state)
+{
+	*state = *state * 1664525U + 1013904223U;
+	return *state;
+}
+
+static int
+stressstr(Str *s)
+{
+	return s->n >= 0 && s->n <= Maxrunes;
+}
+
+void
+engine_randomized_stress(struct ct *t)
+{
+	static Rune text[] = {
+		'a', 'e', 'g', 'i', 'j', 'k', 'm', 'n', 'o', 'r', 's', 't',
+		'u', 'w', 'y', '1', '2', '9', '\'', ' ', L'日',
+	};
+	static Rune modes[] = { 't', 'n', 'k', 's', 'v' };
+	Emojifix f;
+	Lang *vi;
+	Trie *vimap;
+	Keyres res;
+	Caret pos;
+	u32int rnd, mod;
+	uvlong owners[3], owner;
+	int i, j, op;
+
+	vi = getlang(LangVI);
+	if(!CT_CHECK(t, vi != nil))
+		return;
+	vimap = vi->map;
+	vi->map = testvi.map;
+	emojibegin(&f, 0);
+	owners[0] = ownernew();
+	owners[1] = ownernew();
+	owners[2] = ownernew();
+	rnd = 0x5eed1234U;
+	for(i = 0; i < 16000; i++){
+		rnd = stressrand(&rnd);
+		owner = owners[(rnd >> 8) % nelem(owners)];
+		op = rnd % 28;
+		mod = (rnd >> 16) & Mmask;
+		memset(&pos, 0, sizeof pos);
+		pos.valid = (rnd >> 25) & 1;
+		pos.x = (rnd >> 3) & 0x3ff;
+		pos.y = (rnd >> 13) & 0x3ff;
+		pos.w = 1 + ((rnd >> 23) & 0x1f);
+		pos.h = 1 + ((rnd >> 18) & 0x1f);
+		if(op < 13)
+			res = ownerrequestat(owner, Keypress,
+				text[(rnd >> 5) % nelem(text)], mod, &pos);
+		else if(op == 13)
+			res = ownerrequestat(owner, Keypress, Kback, 0, &pos);
+		else if(op == 14)
+			res = ownerrequestat(owner, Keypress, Kret, 0, &pos);
+		else if(op == 15)
+			res = ownerrequestat(owner, Keypress, Kesc, 0, &pos);
+		else if(op == 16)
+			res = ownerrequestat(owner, Keypress, Kdown, 0, &pos);
+		else if(op == 17)
+			res = ownerrequestat(owner, Keypress, Kup, 0, &pos);
+		else if(op == 18)
+			res = ownerrequestat(owner, Keypress, Ktab,
+				(rnd & 0x1000) ? Mshift : 0, &pos);
+		else if(op == 19)
+			res = ownerrequestat(owner, Keypress,
+				modes[(rnd >> 12) % nelem(modes)], Mctrl, &pos);
+		else if(op == 20)
+			res = ownerrequestat(owner, Keypress, 'e', Mctrl, &pos);
+		else if(op == 21)
+			res = ownerrequest(owner, Keyreset, 0, 0);
+		else if(op == 22)
+			res = ownerrequest(owner, Keyrelease, 0, 0);
+		else if(op == 23)
+			res = ownerrequestat(owner, Keycaret, 0, 0, &pos);
+		else if(op == 24)
+			res = ownerrequest(owner, Keypress,
+				Kmodfirst + ((rnd >> 20) & 7), 0);
+		else if(op == 25)
+			res = ownerrequestat(owner, Keypress, 'p', Mctrl, &pos);
+		else if(op == 26)
+			res = ownerrequestat(owner, Keypress, 0xf008, 0, &pos);
+		else
+			res = ownerrequestat(owner, Keypress,
+				'1' + ((rnd >> 11) % 9), 0, &pos);
+
+		if(!stressstr(&res.commit) || !stressstr(&res.preedit) ||
+		   !stressstr(&im.pre) || !stressstr(&im.raw) ||
+		   !stressstr(&search.raw) || !stressstr(&search.text) ||
+		   im.l == nil || im.nkouho < 0 || im.nkouho > Maxkouho ||
+		   im.sel < -1 || im.sel >= Maxkouho ||
+		   (im.nkouho > 0 && im.sel >= im.nkouho)){
+			CT_ERRORF(t, "invalid engine state after stress operation %d", i);
+			break;
+		}
+		for(j = 0; j < im.nkouho; j++)
+			if(!stressstr(&im.kouho[j])){
+				CT_ERRORF(t, "invalid candidate after stress operation %d", i);
+				i = 16000;
+				break;
+			}
+		if(activeowner != 0 && activeowner != owners[0] &&
+		   activeowner != owners[1] && activeowner != owners[2]){
+			CT_ERRORF(t, "unknown active owner after stress operation %d", i);
+			break;
+		}
+	}
+	emojiend(&f);
+	vi->map = vimap;
+}
diff --git a/tests/test.h b/tests/test.h
index 0776244..bff84af 100644
--- a/tests/test.h
+++ b/tests/test.h
@@ -60,6 +60,7 @@ void	engine_emoji_navigation(struct ct*);
 void	engine_emoji_preedit_languages(struct ct*);
 void	engine_emoji_start_and_unknown(struct ct*);
 void	engine_emoji_dictionary_identity(struct ct*);
+void	engine_randomized_stress(struct ct*);
 void	dictionary_candidates(struct ct*);
 void	dictionary_misses_clear_result(struct ct*);
 void	dictionary_emoji_identity(struct ct*);
diff --git a/tests/unit_test.c b/tests/unit_test.c
index 815d5e1..508df79 100644
--- a/tests/unit_test.c
+++ b/tests/unit_test.c
@@ -109,6 +109,7 @@ static const struct ct_test tests[] = {
 	{ "engine/emoji-preedit-languages", engine_emoji_preedit_languages },
 	{ "engine/emoji-start-and-unknown", engine_emoji_start_and_unknown },
 	{ "engine/emoji-dictionary-identity", engine_emoji_dictionary_identity },
+	{ "engine/randomized-stress", engine_randomized_stress },
 	{ "dict/candidates", dictionary_candidates },
 	{ "dict/misses-clear-result", dictionary_misses_clear_result },
 	{ "dict/emoji-identity", dictionary_emoji_identity },