add template literal spans (microsoft#34699)

Author: Kingwl

src/services/outliningElementsCollector.ts

@@ -202,6 +202,9 @@ namespace ts.OutliningElementsCollector {
             case SyntaxKind.JsxSelfClosingElement:
             case SyntaxKind.JsxOpeningElement:
                 return spanForJSXAttributes((<JsxOpeningLikeElement>n).attributes);
+            case SyntaxKind.TemplateExpression:
+            case SyntaxKind.NoSubstitutionTemplateLiteral:
+                return spanForTemplateLiteral(<TemplateExpression | NoSubstitutionTemplateLiteral>n);
         }
 
         function spanForJSXElement(node: JsxElement): OutliningSpan | undefined {
@@ -225,6 +228,13 @@ namespace ts.OutliningElementsCollector {
             return createOutliningSpanFromBounds(node.getStart(sourceFile), node.getEnd(), OutliningSpanKind.Code);
         }
 
+        function spanForTemplateLiteral(node: TemplateExpression | NoSubstitutionTemplateLiteral) {
+            if (node.kind === SyntaxKind.NoSubstitutionTemplateLiteral && node.text.length === 0) {
+                return undefined;
+            }
+            return createOutliningSpanFromBounds(node.getStart(sourceFile), node.getEnd(), OutliningSpanKind.Code);
+        }
+
         function spanForObjectOrArrayLiteral(node: Node, open: SyntaxKind.OpenBraceToken | SyntaxKind.OpenBracketToken = SyntaxKind.OpenBraceToken): OutliningSpan | undefined {
             // If the block has no leading keywords and is inside an array literal or call expression,
             // we only want to collapse the span of the block.

tests/cases/fourslash/getOutliningSpansForTemplateLiteral.ts

@@ -0,0 +1,20 @@
+/// <reference path="fourslash.ts"/>
+
+//// declare function tag(...args: any[]): void
+//// const a = [|`signal line`|]
+//// const b = [|`multi
+//// line`|]
+//// const c = tag[|`signal line`|]
+//// const d = tag[|`multi
+//// line`|]
+//// const e = [|`signal ${1} line`|]
+//// const f = [|`multi
+//// ${1}
+//// line`|]
+//// const g = tag[|`signal ${1} line`|]
+//// const h = tag[|`multi
+//// ${1}
+//// line`|]
+//// const i = ``
+
+verify.outliningSpansInCurrentFile(test.ranges());