Fix the issue 15232 (#16004)

Author: yuit

src/compiler/comments.ts

@@ -58,8 +58,10 @@ namespace ts {
                     }
 
                     const isEmittedNode = node.kind !== SyntaxKind.NotEmittedStatement;
-                    const skipLeadingComments = pos < 0 || (emitFlags & EmitFlags.NoLeadingComments) !== 0;
-                    const skipTrailingComments = end < 0 || (emitFlags & EmitFlags.NoTrailingComments) !== 0;
+                    // We have to explicitly check that the node is JsxText because if the compilerOptions.jsx is "preserve" we will not do any transformation.
+                    // It is expensive to walk entire tree just to set one kind of node to have no comments.
+                    const skipLeadingComments = pos < 0 || (emitFlags & EmitFlags.NoLeadingComments) !== 0 || node.kind === SyntaxKind.JsxText;
+                    const skipTrailingComments = end < 0 || (emitFlags & EmitFlags.NoTrailingComments) !== 0 || node.kind === SyntaxKind.JsxText;
 
                     // Emit leading comments if the position is not synthesized and the node
                     // has not opted out from emitting leading comments.

tests/baselines/reference/commentEmittingInPreserveJsx1.js

@@ -0,0 +1,57 @@
+//// [file.tsx]
+import React = require('react');
+
+<div>
+    // Not Comment
+</div>;
+
+<div>
+    // Not Comment
+    {
+        //Comment just Fine
+    }
+    // Another not Comment
+</div>;
+
+<div>
+    // Not Comment
+    {
+        //Comment just Fine
+        "Hi"
+    }
+    // Another not Comment
+</div>;
+
+<div>
+    /* Not Comment */
+    {
+        //Comment just Fine
+        "Hi"
+    }
+</div>;
+
+//// [file.jsx]
+"use strict";
+exports.__esModule = true;
+var React = require("react");
+<div>
+    // Not Comment
+</div>;
+<div>
+    // Not Comment
+    
+    // Another not Comment
+</div>;
+<div>
+    // Not Comment
+    {
+//Comment just Fine
+"Hi"}
+    // Another not Comment
+</div>;
+<div>
+    /* Not Comment */
+    {
+//Comment just Fine
+"Hi"}
+</div>;

tests/baselines/reference/commentEmittingInPreserveJsx1.symbols

@@ -0,0 +1,45 @@
+=== tests/cases/conformance/jsx/file.tsx ===
+import React = require('react');
+>React : Symbol(React, Decl(file.tsx, 0, 0))
+
+<div>
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+    // Not Comment
+</div>;
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+<div>
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+    // Not Comment
+    {
+        //Comment just Fine
+    }
+    // Another not Comment
+</div>;
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+<div>
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+    // Not Comment
+    {
+        //Comment just Fine
+        "Hi"
+    }
+    // Another not Comment
+</div>;
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+<div>
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+
+    /* Not Comment */
+    {
+        //Comment just Fine
+        "Hi"
+    }
+</div>;
+>div : Symbol(JSX.IntrinsicElements.div, Decl(react.d.ts, 2399, 45))
+

tests/baselines/reference/commentEmittingInPreserveJsx1.types

@@ -0,0 +1,51 @@
+=== tests/cases/conformance/jsx/file.tsx ===
+import React = require('react');
+>React : typeof React
+
+<div>
+><div>    // Not Comment</div> : JSX.Element
+>div : any
+
+    // Not Comment
+</div>;
+>div : any
+
+<div>
+><div>    // Not Comment    {        //Comment just Fine    }    // Another not Comment</div> : JSX.Element
+>div : any
+
+    // Not Comment
+    {
+        //Comment just Fine
+    }
+    // Another not Comment
+</div>;
+>div : any
+
+<div>
+><div>    // Not Comment    {        //Comment just Fine        "Hi"    }    // Another not Comment</div> : JSX.Element
+>div : any
+
+    // Not Comment
+    {
+        //Comment just Fine
+        "Hi"
+>"Hi" : "Hi"
+    }
+    // Another not Comment
+</div>;
+>div : any
+
+<div>
+><div>    /* Not Comment */    {        //Comment just Fine        "Hi"    }</div> : JSX.Element
+>div : any
+
+    /* Not Comment */
+    {
+        //Comment just Fine
+        "Hi"
+>"Hi" : "Hi"
+    }
+</div>;
+>div : any
+

tests/cases/conformance/jsx/commentEmittingInPreserveJsx1.tsx

@@ -0,0 +1,35 @@
+// @filename: file.tsx
+// @jsx: preserve
+// @noLib: true
+// @libFiles: react.d.ts,lib.d.ts
+
+import React = require('react');
+
+<div>
+    // Not Comment
+</div>;
+
+<div>
+    // Not Comment
+    {
+        //Comment just Fine
+    }
+    // Another not Comment
+</div>;
+
+<div>
+    // Not Comment
+    {
+        //Comment just Fine
+        "Hi"
+    }
+    // Another not Comment
+</div>;
+
+<div>
+    /* Not Comment */
+    {
+        //Comment just Fine
+        "Hi"
+    }
+</div>;