From 675f71369d2f7adc4baae3ed08841ed38d638417 Mon Sep 17 00:00:00 2001
From: Sean LeBlanc <sean.s.leblanc@gmail.com>
Date: Sat, 5 Sep 2020 11:24:37 -0700
Subject: [PATCH] feat: add support for multiple followers (with option for
 stack/chain) (#170)

adds support for multiple followers, with an option for whether to stack (keep all followers one step behind player) or chain (keep followers one step behind the follower ahead of them in the list of active followers)

also fixes an issue in the hack options injection regex in the test code

BREAKING CHANGE: this changes the `follower` export to `followers`, since it's now a list
---
 .../follower-test-js-follower-1-snap.png      | Bin 1228 -> 1241 bytes
 ...est-js-multiple-followers-chain-1-snap.png | Bin 0 -> 1234 bytes
 ...est-js-multiple-followers-chain-2-snap.png | Bin 0 -> 1234 bytes
 ...est-js-multiple-followers-stack-1-snap.png | Bin 0 -> 1208 bytes
 ...est-js-multiple-followers-stack-2-snap.png | Bin 0 -> 1206 bytes
 src/follower.js                               |  80 +++++++++----
 src/follower.test.js                          | 110 ++++++++++++++++++
 src/test/bitsy.js                             |   4 +-
 8 files changed, 168 insertions(+), 26 deletions(-)
 create mode 100644 src/__image_snapshots__/follower-test-js-multiple-followers-chain-1-snap.png
 create mode 100644 src/__image_snapshots__/follower-test-js-multiple-followers-chain-2-snap.png
 create mode 100644 src/__image_snapshots__/follower-test-js-multiple-followers-stack-1-snap.png
 create mode 100644 src/__image_snapshots__/follower-test-js-multiple-followers-stack-2-snap.png

diff --git a/src/__image_snapshots__/follower-test-js-follower-1-snap.png b/src/__image_snapshots__/follower-test-js-follower-1-snap.png
index 11254057eee9d58c17b7dda17184289057e58ebe..3059ab51c6b7d1ad4acb87431fe330aeaa88affe 100644
GIT binary patch
delta 22
ecmX@Zd6RR3GB*Qbage(c!@6@aFE=W#W&r?ILkGtI

delta 10
Rcmcb~d4_X>@<xM|EC3iS1Ni^|

diff --git a/src/__image_snapshots__/follower-test-js-multiple-followers-chain-1-snap.png b/src/__image_snapshots__/follower-test-js-multiple-followers-chain-1-snap.png
new file mode 100644
index 0000000000000000000000000000000000000000..c081c05a428ecc2faccc545ce5d72c0459a1f1fe
GIT binary patch
literal 1234
zcmeAS@N?(olHy`uVBq!ia0y~yU<5K5893O0R7}x|G!U;i$lZxy-8q?;3=Awio-U3d
z6?5L+H7pADlyD22o#eiznZ@i0ui!@Bh{>HY3$#R?g1-M=TJ2}?_?yMd-?z^Hc>MM0
z?e*Wq6<%Jx7|&23!`NUz9NKVxdtKA^_3`gMmNJA_{QmiS+2=e4fwIrM4-WsI_TtO4
z2YWuBi?9C|1r$^Rqq6Pg49l0*_CMM4dFkirMa)o(Hk7_+$on(zXyx;{@#lFN4zYky
zT>jtNjepG)WRB-EGlfTg3vTd!TXmaLShlvgjJaWhVKqZQ8b8AgKL!OK28EnAatu>$
zGBZpQX5auK>D}xMsoxkHo<fXz_kB0Rza0CRw=4eF-vO%!YB?jvz>@$s0K`k-XNZ6p
zhsi@#iOL(*2a1BhAD($P{Tchd{d@d=(Z0Ix!JHOP*%%VPF(fclGaM-M|IPOx&hDP-
zo4WP~vTW8n7#(h0e#<z=&eH$?&!zsCisz?qEslR4XfD{72uvmKGVd|Q{5rDli|4P8
z@5}GA*!;YC5}0u1>i8dg;rzK?{oBjqzO|eD{{M<NEyu9o&f)#c7T;TJzVH3A|J>Z)
zKVto#6#u`=pT}}%vNS`>O=gS7E7aGj*G#r$NZ8$8&tCBAQaMwDG{cgc%ngih7#VJJ
zGPD4Z?Oizr8)l$ei<lS^frx)UJHz=CK;!2yILrVdTLy^(K;GSl)eL!j1v2KqT(FrP
zBMX|9@gD%@v;F`6EQRL;VCHG~e9n6RJfLeJcJ19)^ZRSvY4s1cYYOH>-xmc1$60fR
l2ZcKs!FEAxBt+hjFP0GWoq15P3|L4pc)I$ztaD0e0ssIqlAZtn

literal 0
HcmV?d00001

diff --git a/src/__image_snapshots__/follower-test-js-multiple-followers-chain-2-snap.png b/src/__image_snapshots__/follower-test-js-multiple-followers-chain-2-snap.png
new file mode 100644
index 0000000000000000000000000000000000000000..e17ec602f7fd2283be6f60c2d9cae00390d7e5a6
GIT binary patch
literal 1234
zcmeAS@N?(olHy`uVBq!ia0y~yU<5K5893O0R7}x|G!U;i$lZxy-8q?;3=Awio-U3d
z6?5L+H7pZxmv9R_*)Cft>-VAUhQP$_jn`G&xg_RWZmC+fs{Z3U-bNvnJ$hR&9DjZK
zx_rLA!zKCf|BMZ<IT%_vi9@xOUzlrtzdoP-$Ff0q-`~&gouA)jP<ZoD`oQk~X)nG#
zd$8y8x%u|>)1+a>*}j!Mur_nPvgP}lmwy8D7zEV7Xxls41I_a{TfE=%`SnglhZzhY
zbmR5n|JEDcv$eebk>~JWOKLo;Mb`D(eluRYlHLL|u=gf&gHbiZfifnBL?BB3&amK&
z9K(h=5WP2S88kMtGw7&;&HuLNJ?n@3-w(H}{`YSO%={U)3=#)`I_83PfOse1`Z0N^
zDp7f(`oK{(=)?2wru9rVuipMX?^^TscDU$+n|Bx#fN6#&fuG?<-W%(N^ve3_A1;=2
z+;a?gz{ZgH_!~ps{5{+4>%Mr_ynifXTmJj^oV}h0B)>5<JUzCD+2Yp`yI(4G|9|%1
zW3l<ES;*Y5;q-T)jt%>(lJ5W873!bnU$-uWpCRJir*ekx^EQ096aRm8XZ8MnFNFWz
z+qrnZevKM11AM#vj&V+HQ1zi=R#0M|zMpwV>6f_-A1urnIDiS5`35t?Hem)1Ad=qB
z&H&_@34nRKYxo&{*aNi`LDK*Jw{i?MYCxyG)w|DJP~7kun9gqilkxMp<^TTt+zj-o
z4;baVk!$#T&bs~|QuZ?|<3CXOd~W=CUWP*~U=$a>?_Wjr6XqXzc00~3e$NHe4$RdI
jA1dLw6Ou>qlQ-&pl>~ibJ>@Ncg%pFQtDnm{r-UW|Ctk$k

literal 0
HcmV?d00001

diff --git a/src/__image_snapshots__/follower-test-js-multiple-followers-stack-1-snap.png b/src/__image_snapshots__/follower-test-js-multiple-followers-stack-1-snap.png
new file mode 100644
index 0000000000000000000000000000000000000000..9ded9e3126a17c8f019a91c99ac821615250bcd1
GIT binary patch
literal 1208
zcmeAS@N?(olHy`uVBq!ia0y~yU<5K5893O0R7}x|G!U;i$lZxy-8q?;3=Awqo-U3d
z6?5L+HO!N77jX@|^r3GLpZce^EsE~<+V-ef1wCM6lkwfW>i-#Ab&&`b;k$ZfN0)!!
zo^Nk=uVKmkb^n+eUUM+Ca1w|9)_oJM`Tx0p{ST`K_L~3C?*~7>%b@V)3-5#F@wyj3
zK6|j|^Evyve}Q=n0%~CNE%iM^-?G~NCwo3G{rtU%xxs)Dgf^7EXYi{#{|Kmj{c|>k
zL?$qLpZ>o*VLva&^^dn34ji8LSL8w5?t5j2T*B`!0NRpsMvh_1O=gB|!VDZhB)yxR
zA@v(W!&4T9LqK%w9izicTZRNni23V($1?oiCNEcZ^}f70SUph7W_AYV8*l?aJfLyY
zAjV<xP*tMxM)iTBVDN`$^ta%K)wO^A{$I53|I_6{1y6u!?HfY^Lp8&JGX39t4|LuO
zXcRCvY?ywV*}`sTfBnCklmA>hez#g~UlTAb?VMi8Uhw*4{p-hhwkK_WY8C=jF24^{
zxzK($r;Po(Ym@Izp05o`3)R2M8TS9$`zQT*pZxRt%pXqOVNf_Dcc4+-CVT@sL(cav
zz+CXIR-Iu7qr)s)28jc53>)S$ILu&hxN-U|;{k1;8Xa{=e)&?(@S*DsBg1J(j=ag-
zzzF2sj@`%p;2FbpkP8f}8O~Y1|MU2{{8M<&N&e0-r~KZ}<LB?6<^^X5NRF_0zvuJo
zos1xhKz9AUy<J{D-LCQev*y=xYQrA@wJ*<SIPe*sEg_i`Ke^#QL(vcByzR<NHNc{X
N!PC{xWt~$(697zmdfWg2

literal 0
HcmV?d00001

diff --git a/src/__image_snapshots__/follower-test-js-multiple-followers-stack-2-snap.png b/src/__image_snapshots__/follower-test-js-multiple-followers-stack-2-snap.png
new file mode 100644
index 0000000000000000000000000000000000000000..4620638eb9b6be20d860b6cb7b976c15f5159047
GIT binary patch
literal 1206
zcmeAS@N?(olHy`uVBq!ia0y~yU<5K5893O0R7}x|G!U;i$lZxy-8q?;3=Av<o-U3d
z6?5L+bqo@56mbnSxHIu}L6dZnbKf1db)4>eIg6XOb)WfFab8kN<=~NMPsQ`c+m}zj
z&aUwC^38aL0y)M81LDwz^X~QsKVR2>|FM*zyyD--&lf7q891zKn18&D_b#a{F1T0u
z{Jnj>K2T5?jH<VnGfZDr+y7+G=cS*w7coOE+EDtQfv@iTqdlL`t$)tOkjMl^{qFzE
z6ZZ3RJpXvR;lSN#e?=aI?Y>ub$R+*$g1Za~IcMY;rrcy^*ak6KdN(^m>Nkdlrz{MI
zfauseMu(ZU3<;KCk8Jq<JC@=9Hu-mD*Y3;19kZF8f%yj901yvo+%$-Bm^@UKsJu~q
zp!gm9;TiocxM6YJ{{N9jj_22{Vt9X+m*LPG#sdt%bo2JuK4yzk)+`mXr5Rd!Z!_<x
zDT@F1Gur=CwtV^P${7db7&hFQQO<CE-k<As?`}=LGg&?llv0<!XN<91cz+jXOx>NW
z>buqL<w2=#=jHp1e_nt8ls|X(AB+ET4C{)S8#esU<3Augum1$lq`NQQGw9v@<;P%g
z4#@@3l>3$u<Q`rK&+k4n!@o3sh6q0f1s?{5H~VihH$aW3X2|0!kOQV>>CNm9fH~)W
z{lB<81_3oNGArXhQ2BiB{{Mg0-T~_bYR-8h*YNqA_5OK4A98|`t)0!@J#s%;>Sptw
tEB+GO2$YcB$H*W*9j*eR4nO&q$)}n*&#E%N09X()c)I$ztaD0e0svkmY`_2j

literal 0
HcmV?d00001

diff --git a/src/follower.js b/src/follower.js
index b4ecd031..50164710 100644
--- a/src/follower.js
+++ b/src/follower.js
@@ -57,15 +57,25 @@ import {
 
 export var hackOptions = {
 	allowFollowerCollision: false, // if true, the player can walk into the follower and talk to them (possible to get stuck this way)
-	follower: 'a', // id or name of sprite to be the follower; use '' to start without a follower
+	followers: ['a'], // ids or names of sprites to be followers; use [] to start without a follower
 	delay: 200, // delay between each follower step (0 is immediate, 400 is twice as slow as normal)
+	stack: false, // if true, followers stack on top of each other; otherwise, they will form a chain
 };
 
-export var follower;
+export var followers = [];
 var paths = {};
 
 function setFollower(followerName) {
-	follower = followerName && getImage(followerName, bitsy.sprite);
+	var follower = followerName && getImage(followerName, bitsy.sprite);
+	if (!follower) {
+		throw new Error('Failed to find sprite with id/name "' + followerName + '"');
+	}
+	var idx = followers.indexOf(follower);
+	if (idx > 0) {
+		followers.splice(idx, 1);
+	} else {
+		followers.push(follower);
+	}
 	paths[follower.id] = paths[follower.id] || [];
 	takeStep();
 }
@@ -78,22 +88,28 @@ function takeStep() {
 	}
 	walking = true;
 	setTimeout(() => {
-		var path = paths[follower.id];
-		var point = path.shift();
-		if (point) {
-			follower.x = point.x;
-			follower.y = point.y;
-			follower.room = point.room;
-		}
-		walking = false;
-		if (path.length) {
+		let takeAnother = false;
+		followers.forEach(function (follower) {
+			var path = paths[follower.id];
+			var point = path.shift();
+			if (point) {
+				follower.x = point.x;
+				follower.y = point.y;
+				follower.room = point.room;
+			}
+			walking = false;
+			if (path.length) {
+				takeAnother = true;
+			}
+		});
+		if (takeAnother) {
 			takeStep();
 		}
 	}, hackOptions.delay);
 }
 
 after('startExportedGame', function () {
-	setFollower(hackOptions.follower);
+	hackOptions.followers.forEach(setFollower);
 
 	// remove + add player to sprite list to force rendering them on top of follower
 	var p = bitsy.sprite[bitsy.playerId];
@@ -119,7 +135,7 @@ after('update', function () {
 		return;
 	}
 
-	if (!follower) {
+	if (!followers.length) {
 		return;
 	}
 
@@ -146,25 +162,41 @@ after('update', function () {
 	default:
 		break;
 	}
-	paths[follower.id].push(step);
+	followers.forEach(function (follower, idx) {
+		if (idx === 0 || hackOptions.stack) {
+			paths[follower.id].push(step);
+		} else {
+			var prevFollower = followers[idx - 1];
+			var prev = paths[prevFollower.id];
+			paths[follower.id].push(prev[prev.length - 2] || {
+				x: prevFollower.x,
+				y: prevFollower.y,
+				room: prevFollower.room,
+			});
+		}
+	});
 	takeStep();
 });
 
 // make follower walk "through" exits
 before('movePlayerThroughExit', function (exit) {
-	if (follower) {
+	if (followers.length) {
 		movedFollower = true;
-		paths[follower.id].push({
-			x: exit.dest.x,
-			y: exit.dest.y,
-			room: exit.dest.room,
+		followers.forEach(function (follower) {
+			paths[follower.id].push({
+				x: exit.dest.x,
+				y: exit.dest.y,
+				room: exit.dest.room,
+			});
 		});
 		takeStep();
 	}
 });
 
 function filterFollowing(id) {
-	return follower === bitsy.sprite[id] ? null : id;
+	return followers.some(function (follower) {
+		return follower.id === id;
+	}) ? null : id;
 }
 
 var originalGetSpriteLeft;
@@ -221,13 +253,13 @@ addDualDialogTag('followerDelay', function (environment, parameters) {
 	hackOptions.delay = parseInt(parameters[0], 10);
 });
 addDualDialogTag('followerSync', function () {
-	if (follower) {
-		var player = bitsy.player();
+	var player = bitsy.player();
+	followers.forEach(function (follower) {
 		follower.room = player.room;
 		follower.x = player.x;
 		follower.y = player.y;
 		paths[follower.id].length = 0;
-	}
+	});
 });
 
 before('moveSprites', function () {
diff --git a/src/follower.test.js b/src/follower.test.js
index e4a7f7e4..ac22e3ca 100644
--- a/src/follower.test.js
+++ b/src/follower.test.js
@@ -6,6 +6,83 @@ import {
 	delay,
 } from './test/bitsy';
 
+		snapshot, start
+	} from './test/bitsy';
+
+const multiple = `
+
+# BITSY VERSION 7.2
+
+! ROOM_FORMAT 1
+
+PAL 0
+0,82,204
+128,159,255
+255,255,255
+
+ROOM 0
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+0,a,a,a,a,a,a,a,a,a,a,a,a,a,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,0,0,0,0,0,0,0,0,0,0,0,0,a,0
+0,a,a,a,a,a,a,a,a,a,a,a,a,a,a,0
+0,0,0,0,0,0,0,0,0,0,0,0,0,0,0,0
+PAL 0
+
+TIL a
+11111111
+10000001
+10000001
+10011001
+10011001
+10000001
+10000001
+11111111
+
+SPR A
+00011000
+00011000
+00011000
+00111100
+01111110
+10111101
+00100100
+00100100
+POS 0 4,12
+
+SPR a
+00000000
+00000000
+00001000
+00011000
+00001000
+00001000
+00011100
+00000000
+POS 0 6,12
+
+SPR b
+00000000
+00000000
+00011000
+00100100
+00001000
+00010000
+00111100
+00000000
+POS 0 8,12
+`;
+
 test('follower', async () => {
 	await start({
 		hacks: ['follower'],
@@ -19,3 +96,36 @@ test('follower', async () => {
 	await snapshot();
 	await end();
 });
+
+test('multiple followers (chain)', async () => {
+	await start({
+		hacks: [['follower', {
+			allowFollowerCollision: false,
+			followers: ['a', 'b'],
+			delay: 1,
+		}]],
+		gamedata: multiple,
+	});
+	await press('ArrowLeft');
+	await snapshot();
+	await press('ArrowLeft');
+	await snapshot();
+	await end();
+});
+
+test('multiple followers (stack)', async () => {
+	await start({
+		hacks: [['follower', {
+			allowFollowerCollision: false,
+			followers: ['a', 'b'],
+			delay: 1,
+			stack: true,
+		}]],
+		gamedata: multiple,
+	});
+	await press('ArrowLeft');
+	await snapshot();
+	await press('ArrowLeft');
+	await snapshot();
+	await end();
+});
diff --git a/src/test/bitsy.js b/src/test/bitsy.js
index c5e9b511..8eef963d 100644
--- a/src/test/bitsy.js
+++ b/src/test/bitsy.js
@@ -48,7 +48,7 @@ export function delay(ms) {
 	return new Promise((r) => setTimeout(r, ms));
 }
 
-// start pupeteer
+// start puppeteer
 // and configure it for testing a bitsy game
 export async function start({
 	gamedata = '',
@@ -80,7 +80,7 @@ export async function start({
 					return `<script>${hackDist[hack.replace(/\s/g, '-')].replace(/\$([0-9]+)/g, '$$$$$1')}</script>`;
 				}
 				const [hackStr, options] = hack;
-				return `<script>${hackDist[hackStr.replace(/\s/g, '-')].replace(/(var hackOptions.*=)[^]*?;/m, `$1 ${JSON.stringify(options, undefined, '\t')};`).replace(/\$([0-9]+)/g, '$$$$$1')}</script>`;
+				return `<script>${hackDist[hackStr.replace(/\s/g, '-')].replace(/(var hackOptions.*=)[^]*?;$/m, `$1 ${JSON.stringify(options, undefined, '\t')};`).replace(/\$([0-9]+)/g, '$$$$$1')}</script>`;
 			}).join('\n')
 		}$2`);
 	}