Add optionalReplacementSpan to completions response (#40347)

* Add optionalReplacementRange to completions response

* Get the name right

* Fix unit tests

* Fix comment typo

* Fix comment typo

* Baseline

src/server/protocol.ts

@@ -2256,6 +2256,12 @@ namespace ts.server.protocol {
         readonly isGlobalCompletion: boolean;
         readonly isMemberCompletion: boolean;
         readonly isNewIdentifierLocation: boolean;
+        /**
+         * In the absence of `CompletionEntry["replacementSpan"]`, the editor may choose whether to use
+         * this span or its default one. If `CompletionEntry["replacementSpan"]` is defined, that span
+         * must be used to commit that completion entry.
+         */
+        readonly optionalReplacementSpan?: TextSpan;
         readonly entries: readonly CompletionEntry[];
     }
 

src/server/session.ts

@@ -1783,6 +1783,7 @@ namespace ts.server {
 
             const res: protocol.CompletionInfo = {
                 ...completions,
+                optionalReplacementSpan: completions.optionalReplacementSpan && toProtocolTextSpan(completions.optionalReplacementSpan, scriptInfo),
                 entries,
             };
             return res;