Handful more usages of emitIfPresent on optional nodes (#22274)

Author: weswigham

src/compiler/emitter.ts

@@ -568,7 +568,7 @@ namespace ts {
             writeSpace();
             writeKeyword("in");
             writeSpace();
-            emit(node.constraint);
+            emitIfPresent(node.constraint);
         }
 
         function pipelineEmitUnspecified(node: Node): void {
@@ -1046,7 +1046,7 @@ namespace ts {
             }
             emitIfPresent(node.questionToken);
             if (node.parent && node.parent.kind === SyntaxKind.JSDocFunctionType && !node.name) {
-                emit(node.type);
+                emitIfPresent(node.type);
             }
             else {
                 emitTypeAnnotation(node.type);
@@ -1174,14 +1174,14 @@ namespace ts {
             writeSpace();
             writePunctuation("=>");
             writeSpace();
-            emit(node.type);
+            emitIfPresent(node.type);
         }
 
         function emitJSDocFunctionType(node: JSDocFunctionType) {
             write("function");
             emitParameters(node, node.parameters);
             write(":");
-            emit(node.type);
+            emitIfPresent(node.type);
         }
 
 
@@ -1208,7 +1208,7 @@ namespace ts {
             writeSpace();
             writePunctuation("=>");
             writeSpace();
-            emit(node.type);
+            emitIfPresent(node.type);
         }
 
         function emitTypeQuery(node: TypeQueryNode) {
@@ -1322,7 +1322,7 @@ namespace ts {
             }
             writePunctuation(":");
             writeSpace();
-            emit(node.type);
+            emitIfPresent(node.type);
             writeSemicolon();
             if (emitFlags & EmitFlags.SingleLine) {
                 writeSpace();
@@ -1593,7 +1593,7 @@ namespace ts {
 
         function emitYieldExpression(node: YieldExpression) {
             emitTokenWithComment(SyntaxKind.YieldKeyword, node.pos, writeKeyword, node);
-            emit(node.asteriskToken);
+            emitIfPresent(node.asteriskToken);
             emitExpressionWithLeadingSpace(node.expression);
         }
 
@@ -2156,12 +2156,12 @@ namespace ts {
         }
 
         function emitImportClause(node: ImportClause) {
-            emit(node.name);
+            emitIfPresent(node.name);
             if (node.name && node.namedBindings) {
                 emitTokenWithComment(SyntaxKind.CommaToken, node.name.end, writePunctuation, node);
                 writeSpace();
             }
-            emit(node.namedBindings);
+            emitIfPresent(node.namedBindings);
         }
 
         function emitNamespaceImport(node: NamespaceImport) {

src/harness/unittests/printer.ts

@@ -63,6 +63,8 @@ namespace ts {
             // github #18071
             printsCorrectly("regularExpressionLiteral", {}, printer => printer.printFile(createSourceFile("source.ts", "let regex = /abc/;", ScriptTarget.ES2017)));
 
+            // github #22239
+            printsCorrectly("importStatementRemoveComments", { removeComments: true }, printer => printer.printFile(createSourceFile("source.ts", "import {foo} from 'foo';", ScriptTarget.ESNext)));
             printsCorrectly("classHeritageClauses", {}, printer => printer.printFile(createSourceFile(
                 "source.ts",
                 `class A extends B implements C implements D {}`,

tests/baselines/reference/printerApi/printsFileCorrectly.importStatementRemoveComments.js

@@ -0,0 +1 @@
+import { foo } from "foo";