feat(42735): add single line comments to selection ranges (microsoft#42763)

Author: a-tarasyuk

src/services/smartSelection.ts

@@ -13,10 +13,16 @@ namespace ts.SmartSelectionRange {
                 const prevNode: Node | undefined = children[i - 1];
                 const node: Node = children[i];
                 const nextNode: Node | undefined = children[i + 1];
+
                 if (getTokenPosOfNode(node, sourceFile, /*includeJsDoc*/ true) > pos) {
                     break outer;
                 }
 
+                const comment = singleOrUndefined(getTrailingCommentRanges(sourceFile.text, node.end));
+                if (comment && comment.kind === SyntaxKind.SingleLineCommentTrivia) {
+                    pushSelectionCommentRange(comment.pos, comment.end);
+                }
+
                 if (positionShouldSnapToNode(sourceFile, pos, node)) {
                     // 1. Blocks are effectively redundant with SyntaxLists.
                     // 2. TemplateSpans, along with the SyntaxLists containing them, are a somewhat unintuitive grouping
@@ -89,6 +95,16 @@ namespace ts.SmartSelectionRange {
                 }
             }
         }
+
+        function pushSelectionCommentRange(start: number, end: number): void {
+            pushSelectionRange(start, end);
+
+            let pos = start;
+            while (sourceFile.text.charCodeAt(pos) === CharacterCodes.slash) {
+                pos++;
+            }
+            pushSelectionRange(pos, end);
+        }
     }
 
     /**

tests/baselines/reference/smartSelection_comment1.baseline

@@ -0,0 +1,5 @@
+const a = 1; ///**/comment content
+
+               comment content
+             //comment content
+const a = 1; //comment content

tests/baselines/reference/smartSelection_comment2.baseline

@@ -0,0 +1,5 @@
+const a = 1; //a b/**/c d
+
+               a bc d
+             //a bc d
+const a = 1; //a bc d

tests/cases/fourslash/smartSelection_comment1.ts

@@ -0,0 +1,5 @@
+/// <reference path="fourslash.ts" />
+
+////const a = 1; ///**/comment content
+
+verify.baselineSmartSelection();

tests/cases/fourslash/smartSelection_comment2.ts

@@ -0,0 +1,5 @@
+/// <reference path="fourslash.ts" />
+
+////const a = 1; //a b/**/c d
+
+verify.baselineSmartSelection();