Fix smart select to include inner content selection for string literals (#2658)

Co-authored-by: copilot-swe-agent[bot] <198982749+Copilot@users.noreply.github.com>
Co-authored-by: jakebailey <5341706+jakebailey@users.noreply.github.com>

Author: Copilot

internal/ls/selectionranges.go

@@ -142,10 +142,35 @@ func getSmartSelectionRange(l *LanguageService, sourceFile *ast.SourceFile, pos
 						}
 					}
 
+					// Synthesize a stop for '${ ... }' since '${' and '}' actually belong to siblings.
+					if ast.IsTemplateSpan(parent) {
+						templateSpan := parent.AsTemplateSpan()
+						if templateSpan.Literal != nil {
+							// Start from just before the '${' and end after the '}'
+							// The '${' is 2 characters before the expression start
+							spanStart := node.Pos() - 2
+							// The '}' is the first character of the template literal (middle or tail)
+							spanEnd := astnav.GetStartOfNode(templateSpan.Literal, sourceFile, false) + 1
+							// Validate the positions are reasonable
+							text := sourceFile.Text()
+							if spanStart >= 0 && spanEnd <= len(text) && spanStart < spanEnd {
+								result = pushSelectionRange(result, spanStart, spanEnd)
+							}
+						}
+					}
+
 					if !shouldSkipNode(node, parent) {
 						start := astnav.GetStartOfNode(node, sourceFile, false)
 						end := node.End()
 						result = pushSelectionRange(result, start, end)
+
+						// String literals should have a stop both inside and outside their quotes.
+						if ast.IsStringLiteral(node) || node.Kind == ast.KindTemplateExpression || node.Kind == ast.KindNoSubstitutionTemplateLiteral {
+							// Only add inner content range if there's actually content (handles unterminated literals)
+							if start+1 < end-1 {
+								result = pushSelectionRange(result, start+1, end-1)
+							}
+						}
 					}
 
 					next = node
@@ -156,7 +181,7 @@ func getSmartSelectionRange(l *LanguageService, sourceFile *ast.SourceFile, pos
 
 		visitNodes := func(nodes *ast.NodeList, v *ast.NodeVisitor) *ast.NodeList {
 			if nodes != nil && len(nodes.Nodes) > 0 {
-				shouldSkipList := parent != nil && ast.IsVariableDeclarationList(parent)
+				shouldSkipList := parent != nil && (ast.IsVariableDeclarationList(parent) || ast.IsTemplateExpression(parent))
 
 				if !shouldSkipList {
 					start := astnav.GetStartOfNode(nodes.Nodes[0], sourceFile, false)

testdata/baselines/reference/submodule/fourslash/smartSelection/smartSelection_templateStrings.baseline

@@ -4,6 +4,10 @@
 } d`
 
 
+ a b ${
+  'c'
+} d 
+
 `a b ${
   'c'
 } d`
@@ -14,10 +18,16 @@
   '/**/c'
 } d`
 
+   c ↲
   'c'↲
 
+     ${
   'c'
-} d`
+}   
+
+ a b ${
+  'c'
+} d 
 
 `a b ${
   'c'

testdata/baselines/reference/submodule/fourslash/smartSelection/smartSelection_templateStrings.baseline.diff

@@ -1,17 +1,6 @@
 --- old.smartSelection_templateStrings.baseline
 +++ new.smartSelection_templateStrings.baseline
-@@= skipped -3, +3 lines =@@
- } d`
-
-
-- a b ${
--  'c'
--} d 
--
- `a b ${
-   'c'
- } d`
-@@= skipped -14, +10 lines =@@
+@@= skipped -17, +17 lines =@@
    '/**/c'
  } d`
 
@@ -21,18 +10,8 @@
 -
 -  'c'
 -
--
--     ${
--  'c'
--}   
--
-- a b ${
--  'c'
--} d 
++   c ↲
 +  'c'↲
-+
-+  'c'
-+} d`
 
- `a b ${
+      ${
    'c'

testdata/baselines/reference/submodule/fourslash/smartSelection/smartSelection_templateStrings2.baseline

@@ -1,5 +1,5 @@
 // === Smart Selection ===
 `a ${b} /**/c`
 
-     b} c`
+ a ${b} c 
 `a ${b} c`