RyanCavanaugh · Copilot · Jun 28, 2025 · Jun 28, 2025 · Jun 28, 2025 · Jun 28, 2025
diff --git a/.github/copilot-questions.md b/.github/copilot-questions.md
@@ -1,4 +1,5 @@
-Questions I have that I think the developers of this project can help me with:
- * How does control flow analysis represent a circular graph? I checked the documentation server for "cfa" and "control flow"
- * How do I tell if a symbol is in the global scope? I checked the documentation server for topics referencing "symbol" and "global"
- * What is an `EscapedName`, exactly?
+Questions I have that I think the developers of this project can help me with:
+ * How does control flow analysis represent a circular graph? I checked the documentation server for "cfa" and "control flow"
+ * How do I tell if a symbol is in the global scope? I checked the documentation server for topics referencing "symbol" and "global"
+ * What is an `EscapedName`, exactly?
+ * How does TypeScript distinguish between comments inside JSX text vs regular TypeScript comments? I searched for "JSX text comments emitter forEachTrailingCommentRange JSX text ranges" - The issue was that comment iteration doesn't understand JSX context and treats JSX text content as regular comments.
diff --git a/src/compiler/emitter.ts b/src/compiler/emitter.ts
@@ -1253,6 +1253,7 @@ export function createPrinter(printerOptions: PrinterOptions = {}, handlers: Pri
     var detachedCommentsInfo: { nodePos: number; detachedCommentEndPos: number; }[] | undefined;
     var hasWrittenComment = false;
     var commentsDisabled = !!printerOptions.removeComments;
+    var jsxTextPositionCache: Map<number, boolean> | undefined;
     var lastSubstitution: Node | undefined;
     var currentParenthesizerRule: ParenthesizerRule<any> | undefined;
     var { enter: enterComment, exit: exitComment } = performance.createTimerIf(extendedDiagnostics, "commentTime", "beforeComment", "afterComment");
@@ -1387,6 +1388,8 @@ export function createPrinter(printerOptions: PrinterOptions = {}, handlers: Pri
         currentSourceFile = sourceFile;
         currentLineMap = undefined;
         detachedCommentsInfo = undefined;
+        jsxTextPositionCache = undefined; // Clear cache for new source file
+
         if (sourceFile) {
             setSourceMapSource(sourceFile);
         }
@@ -1402,6 +1405,40 @@ export function createPrinter(printerOptions: PrinterOptions = {}, handlers: Pri
         sourceMapsDisabled = !writer || !sourceMapGenerator;
     }
 
+    function isPositionInJsxText(pos: number): boolean {
+        if (!currentSourceFile) return false;
+
+        // Use cache if available
+        if (!jsxTextPositionCache) {
+            jsxTextPositionCache = new Map();
+        }
+
+        if (jsxTextPositionCache.has(pos)) {
+            return jsxTextPositionCache.get(pos)!;
+        }
+
+        // Walk the AST to find if this position is within a JSX text node
+        let found = false;
+
+        function visitNode(node: Node): void {
+            if (found) return;
+
+            if (node.kind === SyntaxKind.JsxText && pos >= node.pos && pos < node.end) {
+                found = true;
+                return;
+            }
+
+            // Only continue traversing if this node might contain the position
+            if (pos >= node.pos && pos < node.end) {
+                forEachChild(node, visitNode);
+            }
+        }
+
+        visitNode(currentSourceFile);
+        jsxTextPositionCache.set(pos, found);
+        return found;
+    }
+
     function reset() {
         nodeIdToGeneratedName = [];
         nodeIdToGeneratedPrivateName = [];
@@ -6096,15 +6133,25 @@ export function createPrinter(printerOptions: PrinterOptions = {}, handlers: Pri
                 forEachLeadingCommentWithoutDetachedComments(cb);
             }
             else {
-                forEachLeadingCommentRange(currentSourceFile.text, pos, cb, /*state*/ pos);
+                forEachLeadingCommentRange(currentSourceFile.text, pos, (commentPos, commentEnd, kind, hasTrailingNewLine, rangePos) => {
+                    // Skip comments that are within JSX text nodes
+                    if (!isPositionInJsxText(commentPos)) {
+                        cb(commentPos, commentEnd, kind, hasTrailingNewLine, rangePos);
+                    }
+                }, /*state*/ pos);
             }
         }
     }
 
     function forEachTrailingCommentToEmit(end: number, cb: (commentPos: number, commentEnd: number, kind: SyntaxKind, hasTrailingNewLine: boolean) => void) {
         // Emit the trailing comments only if the container's end doesn't match because the container should take care of emitting these comments
         if (currentSourceFile && (containerEnd === -1 || (end !== containerEnd && end !== declarationListContainerEnd))) {
-            forEachTrailingCommentRange(currentSourceFile.text, end, cb);
+            forEachTrailingCommentRange(currentSourceFile.text, end, (commentPos, commentEnd, kind, hasTrailingNewLine) => {
+                // Skip comments that are within JSX text nodes
+                if (!isPositionInJsxText(commentPos)) {
+                    cb(commentPos, commentEnd, kind, hasTrailingNewLine);
+                }
+            });
         }
     }
 
@@ -6123,7 +6170,12 @@ export function createPrinter(printerOptions: PrinterOptions = {}, handlers: Pri
             detachedCommentsInfo = undefined;
         }
 
-        forEachLeadingCommentRange(currentSourceFile.text, pos, cb, /*state*/ pos);
+        forEachLeadingCommentRange(currentSourceFile.text, pos, (commentPos, commentEnd, kind, hasTrailingNewLine, rangePos) => {
+            // Skip comments that are within JSX text nodes
+            if (!isPositionInJsxText(commentPos)) {
+                cb(commentPos, commentEnd, kind, hasTrailingNewLine, rangePos);
+            }
+        }, /*state*/ pos);
     }
 
     function emitDetachedCommentsAndUpdateCommentsInfo(range: TextRange) {

diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=preserve).js b/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>;
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=preserve).symbols b/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))
+
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=preserve).types b/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
+>    : ^^^^^^^^^^
+
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=react).errors.txt b/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.
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=react).js b/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,
+    "/* no */", /* 1 */
+    123 /* 2 */,
+    "/* no */");
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=react).symbols b/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))
+
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=react).types b/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
+>    : ^^^^^^^^^^
+
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=react-jsx).errors.txt b/tests/baselines/reference/jsxCommentDuplication(jsx=react-jsx).errors.txt
@@ -0,0 +1,8 @@
+jsxCommentDuplication.tsx(2,13): error TS2875: This JSX tag requires the module path 'react/jsx-runtime' to exist, but none could be found. Make sure you have types for the appropriate package installed.
+
+
+==== jsxCommentDuplication.tsx (1 errors) ====
+    function App() {}
+    const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;
+                ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
+!!! error TS2875: This JSX tag requires the module path 'react/jsx-runtime' to exist, but none could be found. Make sure you have types for the appropriate package installed.
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=react-jsx).js b/tests/baselines/reference/jsxCommentDuplication(jsx=react-jsx).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]
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+var jsx_runtime_1 = require("react/jsx-runtime");
+function App() { }
+var jsx = (0, jsx_runtime_1.jsxs)(App, { children: ["/* no */", /* 1 */ 123 /* 2 */, "/* no */"] });
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=react-jsx).symbols b/tests/baselines/reference/jsxCommentDuplication(jsx=react-jsx).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))
+
diff --git a/tests/baselines/reference/jsxCommentDuplication(jsx=react-jsx).types b/tests/baselines/reference/jsxCommentDuplication(jsx=react-jsx).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
+>    : ^^^^^^^^^^
+
diff --git a/tests/baselines/reference/jsxCommentDuplication.js b/tests/baselines/reference/jsxCommentDuplication.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>;
diff --git a/tests/baselines/reference/jsxCommentDuplication.symbols b/tests/baselines/reference/jsxCommentDuplication.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))
+
diff --git a/tests/baselines/reference/jsxCommentDuplication.types b/tests/baselines/reference/jsxCommentDuplication.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
+>    : ^^^^^^^^^^
+
diff --git a/tests/baselines/reference/jsxCommentDuplicationDebug.js b/tests/baselines/reference/jsxCommentDuplicationDebug.js
@@ -0,0 +1,9 @@
+//// [tests/cases/compiler/jsxCommentDuplicationDebug.tsx] ////
+
+//// [jsxCommentDuplicationDebug.tsx]
+function App() {}
+const jsx = <App>/* before */{/* 1 */ 123 /* 2 */}/* after */</App>;
+
+//// [jsxCommentDuplicationDebug.jsx]
+function App() { }
+var jsx = <App>/* before */{123}/* after */</App>;
diff --git a/tests/baselines/reference/jsxCommentDuplicationDebug.symbols b/tests/baselines/reference/jsxCommentDuplicationDebug.symbols
@@ -0,0 +1,11 @@
+//// [tests/cases/compiler/jsxCommentDuplicationDebug.tsx] ////
+
+=== jsxCommentDuplicationDebug.tsx ===
+function App() {}
+>App : Symbol(App, Decl(jsxCommentDuplicationDebug.tsx, 0, 0))
+
+const jsx = <App>/* before */{/* 1 */ 123 /* 2 */}/* after */</App>;
+>jsx : Symbol(jsx, Decl(jsxCommentDuplicationDebug.tsx, 1, 5))
+>App : Symbol(App, Decl(jsxCommentDuplicationDebug.tsx, 0, 0))
+>App : Symbol(App, Decl(jsxCommentDuplicationDebug.tsx, 0, 0))
+
diff --git a/tests/baselines/reference/jsxCommentDuplicationDebug.types b/tests/baselines/reference/jsxCommentDuplicationDebug.types
@@ -0,0 +1,17 @@
+//// [tests/cases/compiler/jsxCommentDuplicationDebug.tsx] ////
+
+=== jsxCommentDuplicationDebug.tsx ===
+function App() {}
+>App : () => void
+>    : ^^^^^^^^^^
+
+const jsx = <App>/* before */{/* 1 */ 123 /* 2 */}/* after */</App>;
+>jsx : error
+><App>/* before */{/* 1 */ 123 /* 2 */}/* after */</App> : error
+>App : () => void
+>    : ^^^^^^^^^^
+>123 : 123
+>    : ^^^
+>App : () => void
+>    : ^^^^^^^^^^
+
diff --git a/tests/baselines/reference/tsxAttributeResolution14.js b/tests/baselines/reference/tsxAttributeResolution14.js
@@ -35,11 +35,8 @@ function VerticalNavMenuItem(prop) {
 }
 function VerticalNav() {
     return (<div>
-      <VerticalNavMenuItem primaryText={2}/> // error
-      // error
-      <VerticalNavMenuItem justRandomProp={2} primaryText={"hello"}/> // ok
-      // ok
-      <VerticalNavMenuItem justRandomProp1={true} primaryText={"hello"}/> // error
-      // error
+      <VerticalNavMenuItem primaryText={2}/>  // error
+      <VerticalNavMenuItem justRandomProp={2} primaryText={"hello"}/>  // ok
+      <VerticalNavMenuItem justRandomProp1={true} primaryText={"hello"}/>  // error
     </div>);
 }
diff --git a/tests/cases/compiler/jsxCommentDuplication.tsx b/tests/cases/compiler/jsxCommentDuplication.tsx
@@ -0,0 +1,3 @@
+// @jsx: preserve,react,react-jsx
+function App() {}
+const jsx = <App>/* no */{/* 1 */ 123 /* 2 */}/* no */</App>;