fix(63726): fix declaration emit for multiline jsdoc literal types

[Oleksandr Tarasiuk (a-tarasyuk)]

Fixes microsoft/TypeScript#63726

[Copilot]

Pull request overview

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Adds a regression test and adjusts scanner trivia-skipping to correctly preserve multiline JSDoc literal union types during declaration emit (fixes TypeScript issue #63726).

Changes:

• Added a new compiler test case for multiline JSDoc union literal typedefs in JS files.
• Updated the reference baseline to validate correct .d.ts output and preserved JSDoc formatting.
• Adjusted GetTextOfNodeFromSourceText to use JSDoc-aware trivia skipping when extracting text from JSDoc nodes.

Reviewed changes

Copilot reviewed 3 out of 3 changed files in this pull request and generated 3 comments.

File	Description
testdata/tests/cases/compiler/jsdocMultilineUnion.ts	New regression test covering multiline JSDoc literal union typedef formatting.
testdata/baselines/reference/compiler/jsdocMultilineUnion.js	Baseline validating correct declaration emit and preserved multiline JSDoc formatting.
internal/scanner/utilities.go	Uses JSDoc-aware trivia skipping when extracting node text for JSDoc nodes.

[Copilot]

Pull request overview

Copilot reviewed 3 out of 3 changed files in this pull request and generated no new comments.

Suppressed comments (1)

internal/scanner/utilities.go:33

• SkipTriviaEx only removes a JSDoc asterisk while locating the node start; it does not remove prefixes inside a node's span. JSDoc types accept multiline template literals (parser.go:2823), so a type such as @typedef {`a\n * b`} T still emits the embedded *. Normalize every extracted line for descendants of JSDocTypeExpression (as the reference implementation does in utilities.ts:1290-1330) and cover a multiline template literal.

		pos = SkipTriviaEx(sourceText, pos, &SkipTriviaOptions{
			InJSDoc: node.Flags&ast.NodeFlagsJSDoc != 0,
		})

[Jake Bailey (jakebailey)]

The suppressed comment actually seems possibly true, have not checked.

[Jake Bailey (jakebailey)]

Checked, and what it noted is already a 6.0 problem, so nothing new

[Jake Bailey (jakebailey)]

Though, perhaps worth fixing:

diff --git a/internal/scanner/utilities.go b/internal/scanner/utilities.go
index d62247c6e4..096583636f 100644
--- a/internal/scanner/utilities.go
+++ b/internal/scanner/utilities.go
@@ -8,6 +8,7 @@ import (
 	"github.com/microsoft/typescript-go/internal/ast"
 	"github.com/microsoft/typescript-go/internal/core"
 	"github.com/microsoft/typescript-go/internal/debug"
+	"github.com/microsoft/typescript-go/internal/stringutil"
 )
 
 func tokenIsIdentifierOrKeyword(token ast.Kind) bool {
@@ -22,6 +23,32 @@ func GetSourceTextOfNodeFromSourceFile(sourceFile *ast.SourceFile, node *ast.Nod
 	return GetTextOfNodeFromSourceText(sourceFile.Text(), node, includeTrivia)
 }
 
+func isJSDocTypeExpressionOrChild(node *ast.Node) bool {
+	if node.Flags&ast.NodeFlagsJSDoc == 0 {
+		return false
+	}
+	for current := node; current != nil; current = current.Parent {
+		if ast.IsJSDocTypeExpression(current) || ast.IsTypeNode(current) {
+			return true
+		}
+	}
+	return false
+}
+
+func stripJSDocTypePrefixes(text string) string {
+	text = strings.ReplaceAll(text, "\r\n", "\n")
+	text = strings.ReplaceAll(text, "\r", "\n")
+	lines := strings.Split(text, "\n")
+	for i, line := range lines {
+		line = strings.TrimLeftFunc(line, stringutil.IsWhiteSpaceLike)
+		if strings.HasPrefix(line, "*") {
+			line = strings.TrimLeftFunc(line[1:], stringutil.IsWhiteSpaceLike)
+		}
+		lines[i] = line
+	}
+	return strings.Join(lines, "\n")
+}
+
 func GetTextOfNodeFromSourceText(sourceText string, node *ast.Node, includeTrivia bool) string {
 	if ast.NodeIsMissing(node) {
 		return ""
@@ -33,6 +60,9 @@ func GetTextOfNodeFromSourceText(sourceText string, node *ast.Node, includeTrivi
 		})
 	}
 	text := sourceText[pos:node.End()]
+	if isJSDocTypeExpressionOrChild(node) {
+		text = stripJSDocTypePrefixes(text)
+	}
 	if node.Flags&ast.NodeFlagsReparserTransformedLiteral != 0 {
 		// This is similar to `getLiteralTextOfNode` in the printer, but without the context of an `emitContext` to provide overrides
 		if ast.IsStringLiteral(node) {
@@ -48,10 +78,6 @@ func GetTextOfNodeFromSourceText(sourceText string, node *ast.Node, includeTrivi
 		// Fail on any other kinds.
 		debug.FailBadSyntaxKind(node, "Unexpected reparser-transformed node kind")
 	}
-	// if (isJSDocTypeExpressionOrChild(node)) {
-	//     // strip space + asterisk at line start
-	//     text = text.split(/\r\n|\n|\r/).map(line => line.replace(/^\s*\*/, "").trimStart()).join("\n");
-	// }
 	return text
 }