Fix JSX comment duplication in both React and preserve modes

src/compiler/scanner.ts

@@ -3720,6 +3720,9 @@ export function createScanner(
         // These initial values are special because the first line is:
         // firstNonWhitespace = 0 to indicate that we want leading whitespace,
 
+        // Build the text content excluding comments
+        let textContent = "";
+
         while (pos < end) {
             char = charCodeUnchecked(pos);
             if (char === CharacterCodes.openBrace) {
@@ -3739,6 +3742,21 @@ export function createScanner(
                 error(Diagnostics.Unexpected_token_Did_you_mean_or_rbrace, pos, 1);
             }
 
+            // Handle comments - skip /* ... */ style comments
+            if (char === CharacterCodes.slash && charCodeUnchecked(pos + 1) === CharacterCodes.asterisk) {
+                pos += 2; // Skip /*
+                // Find the end of the comment
+                while (pos < end) {
+                    if (charCodeUnchecked(pos) === CharacterCodes.asterisk && charCodeUnchecked(pos + 1) === CharacterCodes.slash) {
+                        pos += 2; // Skip */
+                        break;
+                    }
+                    pos++;
+                }
+                // Continue without adding comment content to textContent
+                continue;
+            }
+
             // FirstNonWhitespace is 0, then we only see whitespaces so far. If we see a linebreak, we want to ignore that whitespaces.
             // i.e (- : whitespace)
             //      <div>----
@@ -3754,13 +3772,16 @@ export function createScanner(
                 break;
             }
             else if (!isWhiteSpaceLike(char)) {
-                firstNonWhitespace = pos;
+                if (firstNonWhitespace === 0) {
+                    firstNonWhitespace = textContent.length;
+                }
             }
 
+            textContent += String.fromCharCode(char);
             pos++;
         }
 
-        tokenValue = text.substring(fullStartPos, pos);
+        tokenValue = textContent;
 
         return firstNonWhitespace === -1 ? SyntaxKind.JsxTextAllWhiteSpaces : SyntaxKind.JsxText;
     }

tests/baselines/reference/jsxCommentDuplication(jsx=preserve).js

@@ -0,0 +1,9 @@
+//// [tests/cases/compiler/jsxCommentDuplication.tsx] ////
+
+//// [jsxCommentDuplication.tsx]
+function App() {}
+const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;
+
+//// [jsxCommentDuplication.jsx]
+function App() { }
+var jsx = <App> /* no */{/* 1 */123 /* 2 */} /* no */</App>;

tests/baselines/reference/jsxCommentDuplication(jsx=preserve).symbols

@@ -0,0 +1,11 @@
+//// [tests/cases/compiler/jsxCommentDuplication.tsx] ////
+
+=== jsxCommentDuplication.tsx ===
+function App() {}
+>App : Symbol(App, Decl(jsxCommentDuplication.tsx, 0, 0))
+
+const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;
+>jsx : Symbol(jsx, Decl(jsxCommentDuplication.tsx, 1, 5))
+>App : Symbol(App, Decl(jsxCommentDuplication.tsx, 0, 0))
+>App : Symbol(App, Decl(jsxCommentDuplication.tsx, 0, 0))
+

tests/baselines/reference/jsxCommentDuplication(jsx=preserve).types

@@ -0,0 +1,17 @@
+//// [tests/cases/compiler/jsxCommentDuplication.tsx] ////
+
+=== jsxCommentDuplication.tsx ===
+function App() {}
+>App : () => void
+>    : ^^^^^^^^^^
+
+const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;
+>jsx : error
+><App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App> : error
+>App : () => void
+>    : ^^^^^^^^^^
+>123 : 123
+>    : ^^^
+>App : () => void
+>    : ^^^^^^^^^^
+

tests/baselines/reference/jsxCommentDuplication(jsx=react).errors.txt

@@ -0,0 +1,8 @@
+jsxCommentDuplication.tsx(2,14): error TS2874: This JSX tag requires 'React' to be in scope, but it could not be found.
+
+
+==== jsxCommentDuplication.tsx (1 errors) ====
+    function App() {}
+    const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;
+                 ~~~
+!!! error TS2874: This JSX tag requires 'React' to be in scope, but it could not be found.

tests/baselines/reference/jsxCommentDuplication(jsx=react).js

@@ -0,0 +1,12 @@
+//// [tests/cases/compiler/jsxCommentDuplication.tsx] ////
+
+//// [jsxCommentDuplication.tsx]
+function App() {}
+const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;
+
+//// [jsxCommentDuplication.js]
+function App() { }
+var jsx = React.createElement(App, null,
+    "", /* 1 */
+    123 /* 2 */,
+    "");

tests/baselines/reference/jsxCommentDuplication(jsx=react).symbols

@@ -0,0 +1,11 @@
+//// [tests/cases/compiler/jsxCommentDuplication.tsx] ////
+
+=== jsxCommentDuplication.tsx ===
+function App() {}
+>App : Symbol(App, Decl(jsxCommentDuplication.tsx, 0, 0))
+
+const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;
+>jsx : Symbol(jsx, Decl(jsxCommentDuplication.tsx, 1, 5))
+>App : Symbol(App, Decl(jsxCommentDuplication.tsx, 0, 0))
+>App : Symbol(App, Decl(jsxCommentDuplication.tsx, 0, 0))
+

tests/baselines/reference/jsxCommentDuplication(jsx=react).types

@@ -0,0 +1,19 @@
+//// [tests/cases/compiler/jsxCommentDuplication.tsx] ////
+
+=== jsxCommentDuplication.tsx ===
+function App() {}
+>App : () => void
+>    : ^^^^^^^^^^
+
+const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;
+>jsx : any
+>    : ^^^
+><App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App> : any
+>                                                 : ^^^
+>App : () => void
+>    : ^^^^^^^^^^
+>123 : 123
+>    : ^^^
+>App : () => void
+>    : ^^^^^^^^^^
+

tests/cases/compiler/jsxCommentDuplication.tsx

@@ -0,0 +1,5 @@
+// @jsx: react,preserve
+// @module: commonjs
+
+function App() {}
+const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;