Allow drag&drop of link to quote in compose form (#36859)

app/javascript/mastodon/features/compose/containers/compose_form_container.js

@@ -18,6 +18,24 @@ import ComposeForm from '../components/compose_form';
 
 const urlLikeRegex = /^https?:\/\/[^\s]+\/[^\s]+$/i;
 
+const processPasteOrDrop = (transfer, e, dispatch) => {
+  if (transfer && transfer.files.length === 1) {
+    dispatch(uploadCompose(transfer.files));
+    e.preventDefault();
+  } else if (transfer && transfer.files.length === 0) {
+    const data = transfer.getData('text/plain');
+    if (!data.match(urlLikeRegex)) return;
+
+    try {
+      const url = new URL(data);
+      dispatch(pasteLinkCompose({ url }));
+      e.preventDefault();
+    } catch {
+      return;
+    }
+  }
+};
+
 const mapStateToProps = state => ({
   text: state.getIn(['compose', 'text']),
   suggestions: state.getIn(['compose', 'suggestions']),
@@ -85,20 +103,11 @@ const mapDispatchToProps = (dispatch, props) => ({
   },
 
   onPaste (e) {
-    if (e.clipboardData && e.clipboardData.files.length === 1) {
-      dispatch(uploadCompose(e.clipboardData.files));
-      e.preventDefault();
-    } else if (e.clipboardData && e.clipboardData.files.length === 0) {
-      const data = e.clipboardData.getData('text/plain');
-      if (!data.match(urlLikeRegex)) return;
+    processPasteOrDrop(e.clipboardData, e, dispatch);
+  },
 
-      try {
-        const url = new URL(data);
-        dispatch(pasteLinkCompose({ url }));
-      } catch {
-        return;
-      }
-    }
+  onDrop (e) {
+    processPasteOrDrop(e.dataTransfer, e, dispatch);
   },
 
   onPickEmoji (position, data, needsSpace) {