microsoft · Copilot · Oct 22, 2025 · Oct 22, 2025 · Oct 22, 2025 · Oct 23, 2025
diff --git a/internal/printer/printer.go b/internal/printer/printer.go
@@ -4384,14 +4384,21 @@ func (p *Printer) emitSourceFile(node *ast.SourceFile) {
 
 	p.writeLine()
 
-	state := p.emitDetachedCommentsBeforeStatementList(node.AsNode(), node.Statements.Loc)
 	p.pushNameGenerationScope(node.AsNode())
 	p.generateAllNames(node.Statements)
 
 	index := 0
+	var state *commentState
 	if node.ScriptKind != core.ScriptKindJSON {
 		p.emitShebangIfNeeded(node)
 		index = p.emitPrologueDirectives(node.Statements)
+		// Emit detached comments after prologue directives but before helpers
+		if !p.writer.IsAtStartOfLine() {
+			p.writeLine()
+		}
+		p.emitDetachedCommentsAndUpdateCommentsInfo(node.Statements.Loc)
+		emitFlags := p.emitContext.EmitFlags(node.AsNode())
+		state = &commentState{emitFlags, node.Statements.Loc, p.containerPos, p.containerEnd, p.declarationListContainerEnd}
 		p.emitHelpers(node.AsNode())
 		if node.IsDeclarationFile {
 			p.emitTripleSlashDirectives(node)

diff --git a/testdata/baselines/reference/compiler/declarationEmitNoCrashOnCrossFileNode.js b/testdata/baselines/reference/compiler/declarationEmitNoCrashOnCrossFileNode.js
diff --git a/testdata/baselines/reference/compiler/emitEndOfFileJSDocComments2.js b/testdata/baselines/reference/compiler/emitEndOfFileJSDocComments2.js
@@ -23,8 +23,8 @@ function test(param) {
 
 //// [emitEndOfFileJSDocComments2.js]
 "use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
 /** @typedef {number} A */
+Object.defineProperty(exports, "__esModule", { value: true });
 /**
  * JSDoc comment for function
  * @param {string} param - A string parameter

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_Watch.js b/testdata/baselines/reference/submodule/compiler/APISample_Watch.js
@@ -85,6 +85,11 @@ watchMain();
 
 //// [APISample_Watch.js]
 "use strict";
+/*
+ * Note: This test is a public API sample. The sample sources can be found
+ *       at: https://github.com/Microsoft/TypeScript-wiki/blob/master/Using-the-Compiler-API.md#writing-an-incremental-program-watcher
+ *       Please log a "breaking change" issue for any API breaking change affecting this issue
+ */
 Object.defineProperty(exports, "__esModule", { value: true });
 const ts = require("typescript");
 const formatHost = {

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_Watch.js.diff b/testdata/baselines/reference/submodule/compiler/APISample_Watch.js.diff
@@ -1,14 +1,8 @@
 --- old.APISample_Watch.js
 +++ new.APISample_Watch.js
-@@= skipped -84, +84 lines =@@
-
- //// [APISample_Watch.js]
- "use strict";
--/*
-- * Note: This test is a public API sample. The sample sources can be found
-- *       at: https://github.com/Microsoft/TypeScript-wiki/blob/master/Using-the-Compiler-API.md#writing-an-incremental-program-watcher
-- *       Please log a "breaking change" issue for any API breaking change affecting this issue
-- */
+@@= skipped -90, +90 lines =@@
+  *       Please log a "breaking change" issue for any API breaking change affecting this issue
+  */
  Object.defineProperty(exports, "__esModule", { value: true });
 -var ts = require("typescript");
 +const ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_WatchWithDefaults.js b/testdata/baselines/reference/submodule/compiler/APISample_WatchWithDefaults.js
@@ -58,6 +58,10 @@ watchMain();
 
 //// [APISample_WatchWithDefaults.js]
 "use strict";
+/*
+ * Note: This test is a public API sample. This uses default sys interface without having to pass anything
+ *       Please log a "breaking change" issue for any API breaking change affecting this issue
+ */
 Object.defineProperty(exports, "__esModule", { value: true });
 const ts = require("typescript");
 function watchMain() {

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_WatchWithDefaults.js.diff b/testdata/baselines/reference/submodule/compiler/APISample_WatchWithDefaults.js.diff
@@ -1,13 +1,8 @@
 --- old.APISample_WatchWithDefaults.js
 +++ new.APISample_WatchWithDefaults.js
-@@= skipped -57, +57 lines =@@
-
- //// [APISample_WatchWithDefaults.js]
- "use strict";
--/*
-- * Note: This test is a public API sample. This uses default sys interface without having to pass anything
-- *       Please log a "breaking change" issue for any API breaking change affecting this issue
-- */
+@@= skipped -62, +62 lines =@@
+  *       Please log a "breaking change" issue for any API breaking change affecting this issue
+  */
  Object.defineProperty(exports, "__esModule", { value: true });
 -var ts = require("typescript");
 +const ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_WatchWithOwnWatchHost.js b/testdata/baselines/reference/submodule/compiler/APISample_WatchWithOwnWatchHost.js
@@ -65,6 +65,10 @@ watchMain();
 
 //// [APISample_WatchWithOwnWatchHost.js]
 "use strict";
+/*
+ * Note: This test is a public API sample. This sample verifies creating abstract builder to watch list of root files
+ *       Please log a "breaking change" issue for any API breaking change affecting this issue
+ */
 Object.defineProperty(exports, "__esModule", { value: true });
 const ts = require("typescript");
 function watchMain() {

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_WatchWithOwnWatchHost.js.diff b/testdata/baselines/reference/submodule/compiler/APISample_WatchWithOwnWatchHost.js.diff
@@ -1,13 +1,8 @@
 --- old.APISample_WatchWithOwnWatchHost.js
 +++ new.APISample_WatchWithOwnWatchHost.js
-@@= skipped -64, +64 lines =@@
-
- //// [APISample_WatchWithOwnWatchHost.js]
- "use strict";
--/*
-- * Note: This test is a public API sample. This sample verifies creating abstract builder to watch list of root files
-- *       Please log a "breaking change" issue for any API breaking change affecting this issue
-- */
+@@= skipped -69, +69 lines =@@
+  *       Please log a "breaking change" issue for any API breaking change affecting this issue
+  */
  Object.defineProperty(exports, "__esModule", { value: true });
 -var ts = require("typescript");
 +const ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_compile.js b/testdata/baselines/reference/submodule/compiler/APISample_compile.js
@@ -48,6 +48,11 @@ compile(process.argv.slice(2), {
 
 //// [APISample_compile.js]
 "use strict";
+/*
+ * Note: This test is a public API sample. The sample sources can be found
+ *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#a-minimal-compiler
+ *       Please log a "breaking change" issue for any API breaking change affecting this issue
+ */
 Object.defineProperty(exports, "__esModule", { value: true });
 exports.compile = compile;
 const ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_compile.js.diff b/testdata/baselines/reference/submodule/compiler/APISample_compile.js.diff
@@ -1,14 +1,7 @@
 --- old.APISample_compile.js
 +++ new.APISample_compile.js
-@@= skipped -47, +47 lines =@@
-
- //// [APISample_compile.js]
- "use strict";
--/*
-- * Note: This test is a public API sample. The sample sources can be found
-- *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#a-minimal-compiler
-- *       Please log a "breaking change" issue for any API breaking change affecting this issue
-- */
+@@= skipped -54, +54 lines =@@
+  */
  Object.defineProperty(exports, "__esModule", { value: true });
  exports.compile = compile;
 -var ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_jsdoc.js b/testdata/baselines/reference/submodule/compiler/APISample_jsdoc.js
@@ -123,6 +123,12 @@ function getSomeOtherTags(node: ts.Node) {
 
 //// [APISample_jsdoc.js]
 "use strict";
+/*
+ * Note: This test is a public API sample. The original sources can be found
+ *       at: https://github.com/YousefED/typescript-json-schema
+ *           https://github.com/vega/ts-json-schema-generator
+ *       Please log a "breaking change" issue for any API breaking change affecting this issue
+ */
 Object.defineProperty(exports, "__esModule", { value: true });
 const ts = require("typescript");
 // excerpted from https://github.com/YousefED/typescript-json-schema

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_jsdoc.js.diff b/testdata/baselines/reference/submodule/compiler/APISample_jsdoc.js.diff
@@ -1,15 +1,8 @@
 --- old.APISample_jsdoc.js
 +++ new.APISample_jsdoc.js
-@@= skipped -122, +122 lines =@@
-
- //// [APISample_jsdoc.js]
- "use strict";
--/*
-- * Note: This test is a public API sample. The original sources can be found
-- *       at: https://github.com/YousefED/typescript-json-schema
-- *           https://github.com/vega/ts-json-schema-generator
-- *       Please log a "breaking change" issue for any API breaking change affecting this issue
-- */
+@@= skipped -129, +129 lines =@@
+  *       Please log a "breaking change" issue for any API breaking change affecting this issue
+  */
  Object.defineProperty(exports, "__esModule", { value: true });
 -var ts = require("typescript");
 +const ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_linter.js b/testdata/baselines/reference/submodule/compiler/APISample_linter.js
@@ -74,6 +74,11 @@ fileNames.forEach(fileName => {
 
 //// [APISample_linter.js]
 "use strict";
+/*
+ * Note: This test is a public API sample. The sample sources can be found
+ *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#traversing-the-ast-with-a-little-linter
+ *       Please log a "breaking change" issue for any API breaking change affecting this issue
+ */
 Object.defineProperty(exports, "__esModule", { value: true });
 exports.delint = delint;
 const ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_linter.js.diff b/testdata/baselines/reference/submodule/compiler/APISample_linter.js.diff
@@ -1,14 +1,7 @@
 --- old.APISample_linter.js
 +++ new.APISample_linter.js
-@@= skipped -73, +73 lines =@@
-
- //// [APISample_linter.js]
- "use strict";
--/*
-- * Note: This test is a public API sample. The sample sources can be found
-- *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#traversing-the-ast-with-a-little-linter
-- *       Please log a "breaking change" issue for any API breaking change affecting this issue
-- */
+@@= skipped -80, +80 lines =@@
+  */
  Object.defineProperty(exports, "__esModule", { value: true });
  exports.delint = delint;
 -var ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_parseConfig.js b/testdata/baselines/reference/submodule/compiler/APISample_parseConfig.js
@@ -46,6 +46,11 @@ export function createProgram(rootFiles: string[], compilerOptionsJson: string):
 
 //// [APISample_parseConfig.js]
 "use strict";
+/*
+ * Note: This test is a public API sample. The sample sources can be found
+ *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#a-minimal-compiler
+ *       Please log a "breaking change" issue for any API breaking change affecting this issue
+ */
 Object.defineProperty(exports, "__esModule", { value: true });
 exports.createProgram = createProgram;
 const ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_parseConfig.js.diff b/testdata/baselines/reference/submodule/compiler/APISample_parseConfig.js.diff
@@ -1,14 +1,7 @@
 --- old.APISample_parseConfig.js
 +++ new.APISample_parseConfig.js
-@@= skipped -45, +45 lines =@@
-
- //// [APISample_parseConfig.js]
- "use strict";
--/*
-- * Note: This test is a public API sample. The sample sources can be found
-- *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#a-minimal-compiler
-- *       Please log a "breaking change" issue for any API breaking change affecting this issue
-- */
+@@= skipped -52, +52 lines =@@
+  */
  Object.defineProperty(exports, "__esModule", { value: true });
  exports.createProgram = createProgram;
 -var ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_transform.js b/testdata/baselines/reference/submodule/compiler/APISample_transform.js
@@ -26,6 +26,11 @@ console.log(JSON.stringify(result));
 
 //// [APISample_transform.js]
 "use strict";
+/*
+ * Note: This test is a public API sample. The sample sources can be found
+ *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#a-simple-transform-function
+ *       Please log a "breaking change" issue for any API breaking change affecting this issue
+ */
 Object.defineProperty(exports, "__esModule", { value: true });
 const ts = require("typescript");
 const source = "let x: string  = 'string'";

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_transform.js.diff b/testdata/baselines/reference/submodule/compiler/APISample_transform.js.diff
@@ -1,14 +1,8 @@
 --- old.APISample_transform.js
 +++ new.APISample_transform.js
-@@= skipped -25, +25 lines =@@
-
- //// [APISample_transform.js]
- "use strict";
--/*
-- * Note: This test is a public API sample. The sample sources can be found
-- *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#a-simple-transform-function
-- *       Please log a "breaking change" issue for any API breaking change affecting this issue
-- */
+@@= skipped -31, +31 lines =@@
+  *       Please log a "breaking change" issue for any API breaking change affecting this issue
+  */
  Object.defineProperty(exports, "__esModule", { value: true });
 -var ts = require("typescript");
 +const ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_watcher.js b/testdata/baselines/reference/submodule/compiler/APISample_watcher.js
@@ -121,6 +121,11 @@ watch(currentDirectoryFiles, { module: ts.ModuleKind.CommonJS });
 
 //// [APISample_watcher.js]
 "use strict";
+/*
+ * Note: This test is a public API sample. The sample sources can be found
+ *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#incremental-build-support-using-the-language-services
+ *       Please log a "breaking change" issue for any API breaking change affecting this issue
+ */
 Object.defineProperty(exports, "__esModule", { value: true });
 const ts = require("typescript");
 function watch(rootFileNames, options) {

diff --git a/testdata/baselines/reference/submodule/compiler/APISample_watcher.js.diff b/testdata/baselines/reference/submodule/compiler/APISample_watcher.js.diff
@@ -1,14 +1,8 @@
 --- old.APISample_watcher.js
 +++ new.APISample_watcher.js
-@@= skipped -120, +120 lines =@@
-
- //// [APISample_watcher.js]
- "use strict";
--/*
-- * Note: This test is a public API sample. The sample sources can be found
-- *       at: https://github.com/Microsoft/TypeScript/wiki/Using-the-Compiler-API#incremental-build-support-using-the-language-services
-- *       Please log a "breaking change" issue for any API breaking change affecting this issue
-- */
+@@= skipped -126, +126 lines =@@
+  *       Please log a "breaking change" issue for any API breaking change affecting this issue
+  */
  Object.defineProperty(exports, "__esModule", { value: true });
 -var ts = require("typescript");
 +const ts = require("typescript");

diff --git a/testdata/baselines/reference/submodule/compiler/amdDependencyComment1.js b/testdata/baselines/reference/submodule/compiler/amdDependencyComment1.js
@@ -8,7 +8,7 @@ m1.f();
 
 //// [amdDependencyComment1.js]
 "use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
 ///<amd-dependency path='bar'/>
+Object.defineProperty(exports, "__esModule", { value: true });
 const m1 = require("m2");
 m1.f();
diff --git a/testdata/baselines/reference/submodule/compiler/amdDependencyComment1.js.diff b/testdata/baselines/reference/submodule/compiler/amdDependencyComment1.js.diff
@@ -1,12 +1,9 @@
 --- old.amdDependencyComment1.js
 +++ new.amdDependencyComment1.js
-@@= skipped -7, +7 lines =@@
-
- //// [amdDependencyComment1.js]
+@@= skipped -9, +9 lines =@@
  "use strict";
--///<amd-dependency path='bar'/>
+ ///<amd-dependency path='bar'/>
  Object.defineProperty(exports, "__esModule", { value: true });
 -var m1 = require("m2");
-+///<amd-dependency path='bar'/>
 +const m1 = require("m2");
  m1.f();
diff --git a/testdata/baselines/reference/submodule/compiler/amdDependencyCommentName1.js b/testdata/baselines/reference/submodule/compiler/amdDependencyCommentName1.js
@@ -8,7 +8,7 @@ m1.f();
 
 //// [amdDependencyCommentName1.js]
 "use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
 ///<amd-dependency path='bar' name='b'/>
+Object.defineProperty(exports, "__esModule", { value: true });
 const m1 = require("m2");
 m1.f();
diff --git a/testdata/baselines/reference/submodule/compiler/amdDependencyCommentName1.js.diff b/testdata/baselines/reference/submodule/compiler/amdDependencyCommentName1.js.diff
@@ -1,12 +1,9 @@
 --- old.amdDependencyCommentName1.js
 +++ new.amdDependencyCommentName1.js
-@@= skipped -7, +7 lines =@@
-
- //// [amdDependencyCommentName1.js]
+@@= skipped -9, +9 lines =@@
  "use strict";
--///<amd-dependency path='bar' name='b'/>
+ ///<amd-dependency path='bar' name='b'/>
  Object.defineProperty(exports, "__esModule", { value: true });
 -var m1 = require("m2");
-+///<amd-dependency path='bar' name='b'/>
 +const m1 = require("m2");
  m1.f();
diff --git a/testdata/baselines/reference/submodule/compiler/cachedContextualTypes.js b/testdata/baselines/reference/submodule/compiler/cachedContextualTypes.js
@@ -26,6 +26,7 @@ createInstance(MenuWorkbenchToolBar, {
 
 //// [cachedContextualTypes.js]
 "use strict";
+// Repro from #52198
 Object.defineProperty(exports, "__esModule", { value: true });
 class MenuWorkbenchToolBar {
     constructor(options) { }

diff --git a/testdata/baselines/reference/submodule/compiler/cachedContextualTypes.js.diff b/testdata/baselines/reference/submodule/compiler/cachedContextualTypes.js.diff
diff --git a/testdata/baselines/reference/submodule/compiler/checkJsdocTypeTagOnExportAssignment1.js b/testdata/baselines/reference/submodule/compiler/checkJsdocTypeTagOnExportAssignment1.js
@@ -20,12 +20,12 @@ a;
 //// [checkJsdocTypeTagOnExportAssignment1.js]
 //// [a.js]
 "use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
 /**
  * @typedef {Object} Foo
  * @property {boolean} a
  * @property {boolean} b
  */
+Object.defineProperty(exports, "__esModule", { value: true });
 /** @type {Foo} */
 exports.default = { c: false };
 //// [b.js]