fix: patch flashlist autoscroll behaviour (#3614)

## 🎯 Goal

This is a forward fix of [this
PR](#3609)
towards V9.

## 🛠 Implementation details

<!-- Provide a description of the implementation -->

## 🎨 UI Changes

<!-- Add relevant screenshots -->

<details>
<summary>iOS</summary>


<table>
    <thead>
        <tr>
            <td>Before</td>
            <td>After</td>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>
                <!--<img src="" /> -->
            </td>
            <td>
                <!--<img src="" /> -->
            </td>
        </tr>
    </tbody>
</table>
</details>


<details>
<summary>Android</summary>

<table>
    <thead>
        <tr>
            <td>Before</td>
            <td>After</td>
        </tr>
    </thead>
    <tbody>
        <tr>
            <td>
                <!--<img src="" /> -->
            </td>
            <td>
                <!--<img src="" /> -->
            </td>
        </tr>
    </tbody>
</table>
</details>

## 🧪 Testing

<!-- Explain how this change can be tested (or why it can't be tested)
-->

## ☑️ Checklist

- [ ] I have signed the [Stream
CLA](https://docs.google.com/forms/d/e/1FAIpQLScFKsKkAJI7mhCr7K9rEIOpqIDThrWxuvxnwUq2XkHyG154vQ/viewform)
(required)
- [ ] PR targets the `develop` branch
- [ ] Documentation is updated
- [ ] New code is tested in main example apps, including all possible
scenarios
  - [ ] SampleApp iOS and Android
  - [ ] Expo iOS and Android

Author: isekovanic

examples/SampleApp/package.json

@@ -21,6 +21,7 @@
     "lint-fix": "eslint . --fix",
     "extract-changelog": "FILTER_PATH='examples/SampleApp' TAG_FORMAT=$npm_package_name'@v${version}' node ../../release/extract-changelog.js",
     "bootstrap": "yarn install",
+    "postinstall": "patch-package",
     "release": "FILTER_PATH='examples/SampleApp' TAG_FORMAT=$npm_package_name'@v${version}' node ../../release/prod",
     "release-next": "echo \"Skipping next release for SampleApp\"",
     "test:unit": "echo \"Skipping unit tests for SampleApp\"",
@@ -102,6 +103,8 @@
     "eslint-plugin-react-hooks": "^5.2.0",
     "eslint-plugin-react-native": "^5.0.0",
     "jest": "^30.0.0",
+    "patch-package": "^8.0.1",
+    "postinstall-postinstall": "^2.1.0",
     "prettier": "^3.5.3",
     "react-test-renderer": "19.1.0",
     "typescript": "5.8.3",

examples/SampleApp/patches/@shopify+flash-list+2.3.1.patch

@@ -0,0 +1,19 @@
+diff --git a/node_modules/@shopify/flash-list/dist/recyclerview/hooks/useBoundDetection.js b/node_modules/@shopify/flash-list/dist/recyclerview/hooks/useBoundDetection.js
+index 767fc5d..f8d4644 100644
+--- a/node_modules/@shopify/flash-list/dist/recyclerview/hooks/useBoundDetection.js
++++ b/node_modules/@shopify/flash-list/dist/recyclerview/hooks/useBoundDetection.js
+@@ -100,6 +100,14 @@ export function useBoundDetection(recyclerViewManager, scrollViewRef) {
+         }
+     }, [recyclerViewManager]);
+     const runAutoScrollToBottomCheck = useCallback(() => {
++        // Suppress MVCP autoscroll while a programmatic scrollToIndex is in
++        // flight. FlashList disables offset projection at the start of
++        // scrollToIndex and re-enables it ~200-300ms after settling. Without
++        // this guard, the sticky pendingAutoscrollToBottom ref races against
++        // scrollToIndex and fires scrollToEnd mid-flight.
++        if (!recyclerViewManager.isOffsetProjectionEnabled) {
++            return;
++        }
+         if (pendingAutoscrollToBottom.current) {
+             pendingAutoscrollToBottom.current = false;
+             requestAnimationFrame(() => {

examples/SampleApp/yarn.lock

@@ -3319,6 +3319,11 @@
   resolved "https://registry.yarnpkg.com/@vscode/sudo-prompt/-/sudo-prompt-9.3.1.tgz#c562334bc6647733649fd42afc96c0eea8de3b65"
   integrity sha512-9ORTwwS74VaTn38tNbQhsA5U44zkJfcb0BdTSyyG6frP4e8KMtHuTXYmwefe5dpL8XB1aGSIVTaLjD3BbWb5iA==
 
+"@yarnpkg/lockfile@^1.1.0":
+  version "1.1.0"
+  resolved "https://registry.yarnpkg.com/@yarnpkg/lockfile/-/lockfile-1.1.0.tgz#e77a97fbd345b76d83245edcd17d393b1b41fb31"
+  integrity sha512-GpSwvyXOcOOlV70vbnzjj4fW5xW/FdUF6nQEt1ENy7m4ZCczi1+/buVUPAqmGfqznsORNFzUMjctTIp8a9tuCQ==
+
 abort-controller@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/abort-controller/-/abort-controller-3.0.0.tgz#eaf54d53b62bae4138e809ca225c8439a6efb392"
@@ -3935,7 +3940,7 @@ ci-info@^2.0.0:
   resolved "https://registry.yarnpkg.com/ci-info/-/ci-info-2.0.0.tgz#67a9e964be31a51e15e5010d58e6f12834002f46"
   integrity sha512-5tK7EtrZ0N+OLFMthtqOj4fI2Jeb88C4CAZPu25LDVUgXJ0A3Js4PMGqrn0JU1W0Mh1/Z8wZzYPxqUrXeBboCQ==
 
-ci-info@^3.2.0:
+ci-info@^3.2.0, ci-info@^3.7.0:
   version "3.9.0"
   resolved "https://registry.yarnpkg.com/ci-info/-/ci-info-3.9.0.tgz#4279a62028a7b1f262f3473fc9605f5e218c59b4"
   integrity sha512-NIxF55hv4nSqQswkAeiOi1r83xy8JldOFDTWiug55KBu9Jnblncd2U6ViHmYgHf01TPZS77NJBhBMKdWj9HQMQ==
@@ -5036,6 +5041,13 @@ find-up@^5.0.0:
     locate-path "^6.0.0"
     path-exists "^4.0.0"
 
+find-yarn-workspace-root@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/find-yarn-workspace-root/-/find-yarn-workspace-root-2.0.0.tgz#f47fb8d239c900eb78179aa81b66673eac88f7bd"
+  integrity sha512-1IMnbjt4KzsQfnhnzNd8wUEgXZ44IzZaZmnLYx7D5FZlaHt2gW20Cri8Q+E/t5tIj4+epTBub+2Zxu/vNILzqQ==
+  dependencies:
+    micromatch "^4.0.2"
+
 firebase@11.3.1:
   version "11.3.1"
   resolved "https://registry.yarnpkg.com/firebase/-/firebase-11.3.1.tgz#1507b2b1e3af17418fbe009e82d7bc30a6b5117c"
@@ -5150,6 +5162,15 @@ fresh@0.5.2:
   resolved "https://registry.yarnpkg.com/fresh/-/fresh-0.5.2.tgz#3d8cadd90d976569fa835ab1f8e4b23a105605a7"
   integrity sha512-zJ2mQYM18rEFOudeV4GShTGIQ7RbzA7ozbU9I/XBpm7kqgMywgmylMwXHxZJmkVoYkna9d2pVXVXPdYTP9ej8Q==
 
+fs-extra@^10.0.0:
+  version "10.1.0"
+  resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-10.1.0.tgz#02873cfbc4084dde127eaa5f9905eef2325d1abf"
+  integrity sha512-oRXApq54ETRj4eMiFzGnHWGy+zo5raudjuxN0b8H7s/RU2oW0Wvsx9O0ACRN/kRq9E8Vu/ReskGB5o3ji+FzHQ==
+  dependencies:
+    graceful-fs "^4.2.0"
+    jsonfile "^6.0.1"
+    universalify "^2.0.0"
+
 fs-extra@^8.1.0:
   version "8.1.0"
   resolved "https://registry.yarnpkg.com/fs-extra/-/fs-extra-8.1.0.tgz#49d43c45a88cd9677668cb7be1b46efdb8d2e1c0"
@@ -5333,7 +5354,7 @@ gopd@^1.0.1, gopd@^1.2.0:
   resolved "https://registry.yarnpkg.com/gopd/-/gopd-1.2.0.tgz#89f56b8217bdbc8802bd299df6d7f1081d7e51a1"
   integrity sha512-ZUKRh6/kUFoAiTAtTYPZJ3hw9wNxx+BIBOijnlG9PnrJsCcSjs1wyyD6vJpaYtgnzDrKYRSqf3OO6Rfa93xsRg==
 
-graceful-fs@^4.1.3, graceful-fs@^4.1.6, graceful-fs@^4.2.0, graceful-fs@^4.2.11, graceful-fs@^4.2.4, graceful-fs@^4.2.9:
+graceful-fs@^4.1.11, graceful-fs@^4.1.3, graceful-fs@^4.1.6, graceful-fs@^4.2.0, graceful-fs@^4.2.11, graceful-fs@^4.2.4, graceful-fs@^4.2.9:
   version "4.2.11"
   resolved "https://registry.yarnpkg.com/graceful-fs/-/graceful-fs-4.2.11.tgz#4183e4e8bf08bb6e05bbb2f7d2e0c8f712ca40e3"
   integrity sha512-RbJ5/jmFcNNCcDV5o9eTnBLJ/HszWV0P73bc+Ff4nS/rJj+YaS6IGyiOL0VoBYX+l1Wrl3k63h/KrH+nhJ0XvQ==
@@ -6421,6 +6442,17 @@ json-stable-stringify-without-jsonify@^1.0.1:
   resolved "https://registry.yarnpkg.com/json-stable-stringify-without-jsonify/-/json-stable-stringify-without-jsonify-1.0.1.tgz#9db7b59496ad3f3cfef30a75142d2d930ad72651"
   integrity sha512-Bdboy+l7tA3OGW6FjyFHWkP5LuByj1Tk33Ljyq0axyzdk9//JSi2u3fP1QSmd1KNwq6VOKYGlAu87CisVir6Pw==
 
+json-stable-stringify@^1.0.2:
+  version "1.3.0"
+  resolved "https://registry.yarnpkg.com/json-stable-stringify/-/json-stable-stringify-1.3.0.tgz#8903cfac42ea1a0f97f35d63a4ce0518f0cc6a70"
+  integrity sha512-qtYiSSFlwot9XHtF9bD9c7rwKjr+RecWT//ZnPvSmEjpV5mmPOCN4j8UjY5hbjNkOwZ/jQv3J6R1/pL7RwgMsg==
+  dependencies:
+    call-bind "^1.0.8"
+    call-bound "^1.0.4"
+    isarray "^2.0.5"
+    jsonify "^0.0.1"
+    object-keys "^1.1.1"
+
 json5@^2.2.3:
   version "2.2.3"
   resolved "https://registry.yarnpkg.com/json5/-/json5-2.2.3.tgz#78cd6f1a19bdc12b73db5ad0c61efd66c1e29283"
@@ -6433,6 +6465,20 @@ jsonfile@^4.0.0:
   optionalDependencies:
     graceful-fs "^4.1.6"
 
+jsonfile@^6.0.1:
+  version "6.2.1"
+  resolved "https://registry.yarnpkg.com/jsonfile/-/jsonfile-6.2.1.tgz#b6e31717f22cc37330b081ce0051ed5de53af2f6"
+  integrity sha512-zwOTdL3rFQ/lRdBnntKVOX6k5cKJwEc1HdilT71BWEu7J41gXIB2MRp+vxduPSwZJPWBxEzv4yH1wYLJGUHX4Q==
+  dependencies:
+    universalify "^2.0.0"
+  optionalDependencies:
+    graceful-fs "^4.1.6"
+
+jsonify@^0.0.1:
+  version "0.0.1"
+  resolved "https://registry.yarnpkg.com/jsonify/-/jsonify-0.0.1.tgz#2aa3111dae3d34a0f151c63f3a45d995d9420978"
+  integrity sha512-2/Ki0GcmuqSrgFyelQq9M05y7PS0mEwuIzrf3f1fPqkVDVRvZrPZtVSMHxdgo8Aq0sxAOb/cr2aqqA3LeWHVPg==
+
 jsonwebtoken@^9.0.2:
   version "9.0.2"
   resolved "https://registry.yarnpkg.com/jsonwebtoken/-/jsonwebtoken-9.0.2.tgz#65ff91f4abef1784697d40952bb1998c504caaf3"
@@ -6516,6 +6562,13 @@ keyv@^4.5.4:
   dependencies:
     json-buffer "3.0.1"
 
+klaw-sync@^6.0.0:
+  version "6.0.0"
+  resolved "https://registry.yarnpkg.com/klaw-sync/-/klaw-sync-6.0.0.tgz#1fd2cfd56ebb6250181114f0a581167099c2b28c"
+  integrity sha512-nIeuVSzdCCs6TDPTqI8w1Yre34sSq7AkZ4B3sfOBbI2CgVSB4Du4aLQijFU2+lhAFCwt9+42Hel6lQNIv6AntQ==
+  dependencies:
+    graceful-fs "^4.1.11"
+
 kleur@^3.0.3:
   version "3.0.3"
   resolved "https://registry.yarnpkg.com/kleur/-/kleur-3.0.3.tgz#a79c9ecc86ee1ce3fa6206d1216c501f147fc07e"
@@ -6948,7 +7001,7 @@ metro@0.83.5, metro@^0.83.1:
     ws "^7.5.10"
     yargs "^17.6.2"
 
-micromatch@^4.0.0, micromatch@^4.0.4, micromatch@^4.0.8:
+micromatch@^4.0.0, micromatch@^4.0.2, micromatch@^4.0.4, micromatch@^4.0.8:
   version "4.0.8"
   resolved "https://registry.yarnpkg.com/micromatch/-/micromatch-4.0.8.tgz#d66fa18f3a47076789320b9b1af32bd86d9fa202"
   integrity sha512-PXwfBhYu0hBCPw8Dn0E+WDYb7af3dSLVWKi3HGv84IdF4TyFoC0ysxFd0Goxw7nSv4T/PzEJQxsYsEiFCKo2BA==
@@ -7019,6 +7072,11 @@ minimatch@^9.0.4:
   dependencies:
     brace-expansion "^2.0.1"
 
+minimist@^1.2.6:
+  version "1.2.8"
+  resolved "https://registry.yarnpkg.com/minimist/-/minimist-1.2.8.tgz#c1a464e7693302e082a075cee0c057741ac4772c"
+  integrity sha512-2yyAR8qBkN3YuheJanUpWC5U3bb5osDywNB8RzDVlDwDHbocAJveqqj1u8+SVD7jkWT4yvsHCpWqqWqAxb0zCA==
+
 "minipass@^5.0.0 || ^6.0.2 || ^7.0.0", minipass@^7.1.2:
   version "7.1.2"
   resolved "https://registry.yarnpkg.com/minipass/-/minipass-7.1.2.tgz#93a9626ce5e5e66bd4db86849e7515e92340a707"
@@ -7236,7 +7294,7 @@ open@^6.2.0:
   dependencies:
     is-wsl "^1.1.0"
 
-open@^7.0.3:
+open@^7.0.3, open@^7.4.2:
   version "7.4.2"
   resolved "https://registry.yarnpkg.com/open/-/open-7.4.2.tgz#b8147e26dcf3e426316c730089fd71edd29c2321"
   integrity sha512-MVHddDVweXZF3awtlAS+6pgKLlm/JgxZ90+/NBurBoQctVOOB/zDdVjcyPzQ+0laDGbsWgrRkflI65sQeOgT9Q==
@@ -7340,6 +7398,26 @@ parseurl@~1.3.3:
   resolved "https://registry.yarnpkg.com/parseurl/-/parseurl-1.3.3.tgz#9da19e7bee8d12dff0513ed5b76957793bc2e8d4"
   integrity sha512-CiyeOxFT/JZyN5m0z9PfXw4SCBJ6Sygz1Dpl0wqjlhDEGGBP1GnsUVEL0p63hoG1fcj3fHynXi9NYO4nWOL+qQ==
 
+patch-package@^8.0.1:
+  version "8.0.1"
+  resolved "https://registry.yarnpkg.com/patch-package/-/patch-package-8.0.1.tgz#79d02f953f711e06d1f8949c8a13e5d3d7ba1a60"
+  integrity sha512-VsKRIA8f5uqHQ7NGhwIna6Bx6D9s/1iXlA1hthBVBEbkq+t4kXD0HHt+rJhf/Z+Ci0F/HCB2hvn0qLdLG+Qxlw==
+  dependencies:
+    "@yarnpkg/lockfile" "^1.1.0"
+    chalk "^4.1.2"
+    ci-info "^3.7.0"
+    cross-spawn "^7.0.3"
+    find-yarn-workspace-root "^2.0.0"
+    fs-extra "^10.0.0"
+    json-stable-stringify "^1.0.2"
+    klaw-sync "^6.0.0"
+    minimist "^1.2.6"
+    open "^7.4.2"
+    semver "^7.5.3"
+    slash "^2.0.0"
+    tmp "^0.2.4"
+    yaml "^2.2.2"
+
 path-exists@^4.0.0:
   version "4.0.0"
   resolved "https://registry.yarnpkg.com/path-exists/-/path-exists-4.0.0.tgz#513bdbe2d3b95d7762e8c1137efa195c6c61b5b3"
@@ -7418,6 +7496,11 @@ possible-typed-array-names@^1.0.0:
   resolved "https://registry.yarnpkg.com/possible-typed-array-names/-/possible-typed-array-names-1.1.0.tgz#93e3582bc0e5426586d9d07b79ee40fc841de4ae"
   integrity sha512-/+5VFTchJDoVj3bhoqi6UeymcD00DAwb1nJwamzPvHEszJ4FpF6SNNbUbOS8yI56qHzdV8eK0qEfOSiodkTdxg==
 
+postinstall-postinstall@^2.1.0:
+  version "2.1.0"
+  resolved "https://registry.yarnpkg.com/postinstall-postinstall/-/postinstall-postinstall-2.1.0.tgz#4f7f77441ef539d1512c40bd04c71b06a4704ca3"
+  integrity sha512-7hQX6ZlZXIoRiWNrbMQaLzUUfH+sSx39u8EJ9HYuDc1kLo9IXKWjM5RSquZN1ad5GnH8CGFM78fsAAQi3OKEEQ==
+
 prelude-ls@^1.2.1:
   version "1.2.1"
   resolved "https://registry.yarnpkg.com/prelude-ls/-/prelude-ls-1.2.1.tgz#debc6489d7a6e6b0e7611888cec880337d316396"
@@ -8184,6 +8267,11 @@ sisteransi@^1.0.5:
   resolved "https://registry.yarnpkg.com/sisteransi/-/sisteransi-1.0.5.tgz#134d681297756437cc05ca01370d3a7a571075ed"
   integrity sha512-bLGGlR1QxBcynn2d5YmDX4MGjlZvy2MRBDRNHLJ8VI6l6+9FUiyTFNJ0IveOSP0bcXgVDPRcfGqA0pjaqUpfVg==
 
+slash@^2.0.0:
+  version "2.0.0"
+  resolved "https://registry.yarnpkg.com/slash/-/slash-2.0.0.tgz#de552851a1759df3a8f206535442f5ec4ddeab44"
+  integrity sha512-ZYKh3Wh2z1PpEXWr0MpSBZ0V6mZHAQfYevttO11c51CaWjGTaadiKZ+wVt1PbMlDV5qhMFslpZCemhwOK7C89A==
+
 slash@^3.0.0:
   version "3.0.0"
   resolved "https://registry.yarnpkg.com/slash/-/slash-3.0.0.tgz#6539be870c165adbd5240220dbe361f1bc4d4634"
@@ -8530,6 +8618,11 @@ throat@^5.0.0:
   resolved "https://registry.yarnpkg.com/throat/-/throat-5.0.0.tgz#c5199235803aad18754a667d659b5e72ce16764b"
   integrity sha512-fcwX4mndzpLQKBS1DVYhGAcYaYt7vsHNIvQV+WXMvnow5cgjPphq5CaayLaGsjRdSCKZFNGt7/GYAuXaNOiYCA==
 
+tmp@^0.2.4:
+  version "0.2.5"
+  resolved "https://registry.yarnpkg.com/tmp/-/tmp-0.2.5.tgz#b06bcd23f0f3c8357b426891726d16015abfd8f8"
+  integrity sha512-voyz6MApa1rQGUxT3E+BK7/ROe8itEx7vD8/HEvt4xwXucvQ5G5oeEiHkmHZJuBO21RpOf+YYm9MOivj709jow==
+
 tmpl@1.0.5:
   version "1.0.5"
   resolved "https://registry.yarnpkg.com/tmpl/-/tmpl-1.0.5.tgz#8683e0b902bb9c20c4f726e3c0b69f36518c07cc"
@@ -8716,6 +8809,11 @@ universalify@^0.1.0:
   resolved "https://registry.yarnpkg.com/universalify/-/universalify-0.1.2.tgz#b646f69be3942dabcecc9d6639c80dc105efaa66"
   integrity sha512-rBJeI5CXAlmy1pV+617WB9J63U6XcazHHF2f2dbJix4XzpUF0RS3Zbj0FGIOCAva5P/d/GBOYaACQ1w+0azUkg==
 
+universalify@^2.0.0:
+  version "2.0.1"
+  resolved "https://registry.yarnpkg.com/universalify/-/universalify-2.0.1.tgz#168efc2180964e6386d061e094df61afe239b18d"
+  integrity sha512-gptHNQghINnc/vTGIk0SOFGFNXw7JVrlRUtConJRlvaw6DuX0wO5Jeko9sWrMBhh+PsYAZ7oXAiOnf/UKogyiw==
+
 unpipe@1.0.0, unpipe@~1.0.0:
   version "1.0.0"
   resolved "https://registry.yarnpkg.com/unpipe/-/unpipe-1.0.0.tgz#b2bf4ee8514aae6165b4817829d21b2ef49904ec"
@@ -9034,6 +9132,11 @@ yaml@^2.2.1:
   resolved "https://registry.yarnpkg.com/yaml/-/yaml-2.7.0.tgz#aef9bb617a64c937a9a748803786ad8d3ffe1e98"
   integrity sha512-+hSoy/QHluxmC9kCIJyL/uyFmLmc+e5CFR5Wa+bpIhIj85LVb9ZH2nVnqrHoSvKogwODv0ClqZkmiSSaIH5LTA==
 
+yaml@^2.2.2:
+  version "2.9.0"
+  resolved "https://registry.yarnpkg.com/yaml/-/yaml-2.9.0.tgz#78274afd93598a1dfdd6130df6a566defcbf9aa4"
+  integrity sha512-2AvhNX3mb8zd6Zy7INTtSpl1F15HW6Wnqj0srWlkKLcpYl/gMIMJiyuGq2KeI2YFxUPjdlB+3Lc10seMLtL4cA==
+
 yaml@^2.6.1:
   version "2.8.3"
   resolved "https://registry.yarnpkg.com/yaml/-/yaml-2.8.3.tgz#a0d6bd2efb3dd03c59370223701834e60409bd7d"

package/src/components/MessageList/MessageFlashList.tsx

@@ -431,7 +431,7 @@ const MessageFlashListWithContext = (props: MessageFlashListPropsWithContext) =>
     if (indexOfParentInMessageList === -1) {
       loadChannelAroundMessage({ messageId: targetedMessage, setTargetedMessage });
     } else {
-      scrollToDebounceTimeoutRef.current = setTimeout(() => {
+      scrollToDebounceTimeoutRef.current = setTimeout(async () => {
         clearTimeout(scrollToDebounceTimeoutRef.current);
 
         const scrollToIndex = async () => {
@@ -442,20 +442,18 @@ const MessageFlashListWithContext = (props: MessageFlashListPropsWithContext) =>
           }
 
           await list.scrollToIndex({
-            index: indexOfParentInMessageList,
             animated: true,
+            index: indexOfParentInMessageList,
             viewPosition: 0.5,
           });
 
           return true;
         };
 
+        await scrollToIndex();
         requestAnimationFrame(async () => {
           await scrollToIndex();
-          requestAnimationFrame(async () => {
-            await scrollToIndex();
-            setTargetedMessage(undefined);
-          });
+          setTargetedMessage(undefined);
         });
       }, WAIT_FOR_SCROLL_TIMEOUT);
     }