From 0f920d7c619bacf3d033ec551a9194fd075cd909 Mon Sep 17 00:00:00 2001
From: Nathan Pixodeo <nathan@pixodeo.net>
Date: Fri, 26 Jun 2026 09:22:30 +0200
Subject: [PATCH] Use project hashtag for OSMCha filters

---
 frontend/src/utils/osmchaLink.js            | 15 ++++++++++++++-
 frontend/src/utils/tests/osmchaLink.test.js | 16 ++++++++++++++++
 2 files changed, 30 insertions(+), 1 deletion(-)

diff --git a/frontend/src/utils/osmchaLink.js b/frontend/src/utils/osmchaLink.js
index 7d3dc7bbfd..e517781f90 100644
--- a/frontend/src/utils/osmchaLink.js
+++ b/frontend/src/utils/osmchaLink.js
@@ -1,3 +1,5 @@
+import { retrieveDefaultChangesetComment } from './defaultChangesetComment';
+
 export function formatOSMChaLink(infoObj) {
   const baseURL = 'https://osmcha.org/';
   // If a custom filter id is given, ignores everything else
@@ -26,7 +28,7 @@ export function formatOSMChaLink(infoObj) {
   }
 
   if (infoObj.changesetComment) {
-    filterParams['comment'] = buildFilter(infoObj.changesetComment);
+    filterParams['comment'] = buildFilter(getOsmchaCommentFilter(infoObj));
   }
 
   if (typeof infoObj.usernames === 'object') {
@@ -36,6 +38,17 @@ export function formatOSMChaLink(infoObj) {
   return `${baseURL}?filters=${encodeURIComponent(JSON.stringify(filterParams))}`;
 }
 
+function getOsmchaCommentFilter(infoObj) {
+  if (infoObj.projectId) {
+    const defaultProjectComment = retrieveDefaultChangesetComment(
+      infoObj.changesetComment,
+      infoObj.projectId,
+    );
+    return defaultProjectComment[0] || infoObj.changesetComment;
+  }
+  return infoObj.changesetComment;
+}
+
 function buildFilterValue(value) {
   return { label: value, value: value };
 }
diff --git a/frontend/src/utils/tests/osmchaLink.test.js b/frontend/src/utils/tests/osmchaLink.test.js
index a3d3940848..e15847c6e1 100644
--- a/frontend/src/utils/tests/osmchaLink.test.js
+++ b/frontend/src/utils/tests/osmchaLink.test.js
@@ -21,6 +21,22 @@ describe('test OSMCha link to project', () => {
     );
   });
 
+  it('uses only the default project hashtag from a project changeset comment', () => {
+    const project = {
+      projectId: 46866,
+      osmchaFilterId: null,
+      aoiBBOX: '139.408264,-5.163437,140.252838,-4.521666',
+      changesetComment:
+        '#hotosm-project-46866 mapped buildings in Indonesia for #msf #missingmaps #indonesia25',
+      created: '2026-03-23T12:20:42.460024Z',
+    };
+    expect(formatOSMChaLink(project)).toBe(
+      `https://osmcha.org/?filters=${encodeURIComponent(
+        '{"in_bbox":[{"label":"139.408264,-5.163437,140.252838,-4.521666","value":"139.408264,-5.163437,140.252838,-4.521666"}],"area_lt":[{"label":2,"value":2}],"date__gte":[{"label":"2026-03-23","value":"2026-03-23"}],"comment":[{"label":"#hotosm-project-46866","value":"#hotosm-project-46866"}]}',
+      )}`,
+    );
+  });
+
   it('with aoiBBOX as a list', () => {
     const project = {
       osmchaFilterId: null,