Fix check for allowMultipleSelections

FIX: Make sure transactions cannot add multiple selections when `allowMultipleSelections` is false. Closes codemirror/dev#1288
codemirror · Nov 2, 2023 · a14b093 · a14b093
1 parent 10d5f42
commit a14b093
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diff --git a/src/state.ts b/src/state.ts
@@ -120,7 +120,8 @@ export class EditorState {
     } else {
       startValues = tr.startState.values.slice()
     }
-    new EditorState(conf, tr.newDoc, tr.newSelection, startValues, (state, slot) => slot.update(state, tr), tr)
+    let selection = tr.startState.facet(allowMultipleSelections) ? tr.newSelection : tr.newSelection.asSingle()
+    new EditorState(conf, tr.newDoc, selection, startValues, (state, slot) => slot.update(state, tr), tr)
   }
 
   /// Create a [transaction spec](#state.TransactionSpec) that

diff --git a/test/test-state.ts b/test/test-state.ts
@@ -151,6 +151,16 @@ describe("EditorState", () => {
     ist(state3.facet(facet).join(), "2,1")
   })
 
+  it("blocks multiple selections when not allowed", () => {
+    let cursors = EditorSelection.create([EditorSelection.cursor(0), EditorSelection.cursor(1)])
+    let state = EditorState.create({
+      selection: cursors,
+      doc: "123"
+    })
+    ist(state.selection.ranges.length, 1)
+    ist(state.update({selection: cursors}).state.selection.ranges.length, 1)
+  })
+
   describe("changeByRange", () => {
     it("can make simple changes", () => {
       let state = EditorState.create({doc: "hi"})