Fix leading source file comment emit bugs (#1945)

Author: jakebailey

internal/printer/printer.go

@@ -4384,18 +4384,24 @@ 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)
+		if !p.writer.IsAtStartOfLine() {
+			p.writeLine()
+		}
+		state = p.emitDetachedCommentsBeforeStatementList(node.AsNode(), node.Statements.Loc)
 		p.emitHelpers(node.AsNode())
 		if node.IsDeclarationFile {
 			p.emitTripleSlashDirectives(node)
 		}
+	} else {
+		state = p.emitDetachedCommentsBeforeStatementList(node.AsNode(), node.Statements.Loc)
 	}
 
 	// !!! Emit triple-slash directives
@@ -5083,7 +5089,7 @@ func (p *Printer) emitDetachedCommentsBeforeStatementList(node *ast.Node, detach
 	containerPos := p.containerPos
 	containerEnd := p.containerEnd
 	declarationListContainerEnd := p.declarationListContainerEnd
-	skipLeadingComments := emitFlags&EFNoLeadingComments == 0 && !ast.PositionIsSynthesized(detachedRange.Pos())
+	skipLeadingComments := ast.PositionIsSynthesized(detachedRange.Pos()) || emitFlags&EFNoLeadingComments != 0
 
 	if !skipLeadingComments {
 		p.emitDetachedCommentsAndUpdateCommentsInfo(detachedRange)

testdata/baselines/reference/compiler/declarationEmitNoCrashOnCrossFileNode.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

testdata/baselines/reference/compiler/emitEndOfFileJSDocComments2.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 = {

testdata/baselines/reference/submodule/compiler/APISample_Watch.js

@@ -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");

testdata/baselines/reference/submodule/compiler/APISample_Watch.js.diff

@@ -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() {

testdata/baselines/reference/submodule/compiler/APISample_WatchWithDefaults.js

@@ -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");

testdata/baselines/reference/submodule/compiler/APISample_WatchWithDefaults.js.diff

@@ -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() {

testdata/baselines/reference/submodule/compiler/APISample_WatchWithOwnWatchHost.js

@@ -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");

testdata/baselines/reference/submodule/compiler/APISample_WatchWithOwnWatchHost.js.diff

@@ -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");