Remove duplication from transformers

src/compiler/transformer.ts

@@ -73,7 +73,7 @@ namespace ts {
 
         addRange(transformers, customTransformers && customTransformers.after);
 
-        return transformers;
+        return map(transformers, (tf: TransformerFactory<SourceFile>) => (context: TransformationContext) => chainBundle(tf(context)));
     }
 
     export function noEmitSubstitution(_hint: EmitHint, node: Node) {

src/compiler/transformers/es2015.ts

@@ -305,7 +305,7 @@ namespace ts {
          */
         let enabledSubstitutions: ES2015SubstitutionFlags;
 
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
             if (node.isDeclarationFile) {

src/compiler/transformers/es2016.ts

@@ -3,7 +3,7 @@ namespace ts {
     export function transformES2016(context: TransformationContext) {
         const { hoistVariableDeclaration } = context;
 
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
             if (node.isDeclarationFile) {

src/compiler/transformers/es2017.ts

@@ -49,7 +49,7 @@ namespace ts {
         context.onEmitNode = onEmitNode;
         context.onSubstituteNode = onSubstituteNode;
 
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
             if (node.isDeclarationFile) {

src/compiler/transformers/es2018.ts

@@ -33,7 +33,7 @@ namespace ts {
         /** A set of node IDs for generated super accessors. */
         const substitutedSuperAccessors: boolean[] = [];
 
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
             if (node.isDeclarationFile) {

src/compiler/transformers/es2019.ts

@@ -1,7 +1,7 @@
 /*@internal*/
 namespace ts {
     export function transformES2019(context: TransformationContext) {
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
             if (node.isDeclarationFile) {

src/compiler/transformers/es5.ts

@@ -24,7 +24,7 @@ namespace ts {
         context.onSubstituteNode = onSubstituteNode;
         context.enableSubstitution(SyntaxKind.PropertyAccessExpression);
         context.enableSubstitution(SyntaxKind.PropertyAssignment);
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         /**
          * Transforms an ES5 source file to ES3.

src/compiler/transformers/esnext.ts

@@ -1,7 +1,7 @@
 /*@internal*/
 namespace ts {
     export function transformESNext(context: TransformationContext) {
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
             if (node.isDeclarationFile) {

src/compiler/transformers/generators.ts

@@ -290,7 +290,7 @@ namespace ts {
         let currentExceptionBlock: ExceptionBlock | undefined; // The current exception block.
         let withBlockStack: WithBlock[] | undefined; // A stack containing `with` blocks.
 
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
             if (node.isDeclarationFile || (node.transformFlags & TransformFlags.ContainsGenerator) === 0) {

src/compiler/transformers/jsx.ts

@@ -4,7 +4,7 @@ namespace ts {
         const compilerOptions = context.getCompilerOptions();
         let currentSourceFile: SourceFile;
 
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         /**
          * Transform JSX-specific syntax in a SourceFile.

src/compiler/transformers/module/es2015.ts

@@ -10,7 +10,7 @@ namespace ts {
         context.enableSubstitution(SyntaxKind.Identifier);
 
         let currentSourceFile: SourceFile | undefined;
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         function transformSourceFile(node: SourceFile) {
             if (node.isDeclarationFile) {

src/compiler/transformers/module/module.ts

@@ -45,7 +45,7 @@ namespace ts {
         let noSubstitution: boolean[]; // Set of nodes for which substitution rules should be ignored.
         let needUMDDynamicImportHelper: boolean;
 
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         /**
          * Transforms the module aspects of a SourceFile.

src/compiler/transformers/module/system.ts

@@ -39,7 +39,7 @@ namespace ts {
         let enclosingBlockScopedContainer: Node;
         let noSubstitution: boolean[] | undefined; // Set of nodes for which substitution rules should be ignored.
 
-        return chainBundle(transformSourceFile);
+        return transformSourceFile;
 
         /**
          * Transforms the module aspects of a SourceFile.

src/compiler/transformers/ts.ts

@@ -89,23 +89,7 @@ namespace ts {
          */
         let pendingExpressions: Expression[] | undefined;
 
-        return transformSourceFileOrBundle;
-
-        function transformSourceFileOrBundle(node: SourceFile | Bundle) {
-            if (node.kind === SyntaxKind.Bundle) {
-                return transformBundle(node);
-            }
-            return transformSourceFile(node);
-        }
-
-        function transformBundle(node: Bundle) {
-            return createBundle(node.sourceFiles.map(transformSourceFile), mapDefined(node.prepends, prepend => {
-                if (prepend.kind === SyntaxKind.InputFiles) {
-                    return createUnparsedSourceFile(prepend, "js");
-                }
-                return prepend;
-            }));
-        }
+        return transformSourceFile;
 
         /**
          * Transform TypeScript-specific syntax in a SourceFile.

src/compiler/transformers/utilities.ts

@@ -33,7 +33,12 @@ namespace ts {
         }
 
         function transformBundle(node: Bundle) {
-            return createBundle(map(node.sourceFiles, transformSourceFile), node.prepends);
+            return createBundle(node.sourceFiles.map(transformSourceFile), mapDefined(node.prepends, prepend => {
+                if (prepend.kind === SyntaxKind.InputFiles) {
+                    return createUnparsedSourceFile(prepend, "js");
+                }
+                return prepend;
+            }));
         }
     }
 
@@ -255,4 +260,4 @@ namespace ts {
             return result;
         };
     }
-}
+}