add IIFETranspiler

Author: KSDaemon

packages/cubejs-schema-compiler/src/compiler/DataSchemaCompiler.ts

@@ -688,18 +688,7 @@ export class DataSchemaCompiler {
       return this.compiledScriptCache.get(cacheKey)!;
     }
 
-    // As we run all data model files in the same context,
-    // we need to wrap the code in an IIFE to avoid errors like:
-    // Identifier 'xxx' has already been declared,
-    // avoid polluting and modifying the global scope,
-    // and to provide a controlled environment for the code execution.
-    const wrappedCode = `
-      (function() {
-        ${file.content}
-      })();
-    `;
-
-    const script = new vm.Script(wrappedCode, { filename: file.fileName });
+    const script = new vm.Script(file.content, { filename: file.fileName });
     this.compiledScriptCache.set(cacheKey, script);
     return script;
   }

packages/cubejs-schema-compiler/src/compiler/PrepareCompiler.ts

@@ -9,6 +9,7 @@ import { DataSchemaCompiler } from './DataSchemaCompiler';
 import {
   CubeCheckDuplicatePropTranspiler,
   CubePropContextTranspiler,
+  IIFETranspiler,
   ImportExportTranspiler,
   TranspilerInterface,
   ValidationTranspiler,
@@ -63,6 +64,7 @@ export const prepareCompiler = (repo: SchemaFileRepository, options: PrepareComp
     new ValidationTranspiler(),
     new ImportExportTranspiler(),
     new CubePropContextTranspiler(cubeSymbols, cubeDictionary, viewCompiler),
+    new IIFETranspiler(),
   ];
 
   if (!options.allowJsDuplicatePropsInSchema) {

packages/cubejs-schema-compiler/src/compiler/transpilers/IIFETranspiler.ts

@@ -0,0 +1,36 @@
+import * as t from '@babel/types';
+import type { NodePath } from '@babel/traverse';
+import type { TranspilerInterface, TraverseObject } from './transpiler.interface';
+import type { ErrorReporter } from '../ErrorReporter';
+
+/**
+ * IIFETranspiler wraps the entire file content in an Immediately Invoked Function Expression (IIFE).
+ * This prevents:
+ * - Variable redeclaration errors when multiple files define the same variables
+ * - Global scope pollution between data model files
+ * - Provides isolated execution context for each file
+ */
+export class IIFETranspiler implements TranspilerInterface {
+  public traverseObject(_reporter: ErrorReporter): TraverseObject {
+    return {
+      Program: (path: NodePath<t.Program>) => {
+        const { body } = path.node;
+
+        if (body.length > 0) {
+          // Create an IIFE that wraps all the existing statements
+          const iife = t.callExpression(
+            t.functionExpression(
+              null, // anonymous function
+              [],
+              t.blockStatement(body)
+            ),
+            []
+          );
+
+          // Replace the program body with the IIFE
+          path.node.body = [t.expressionStatement(iife)];
+        }
+      }
+    };
+  }
+}

packages/cubejs-schema-compiler/src/compiler/transpilers/index.ts

@@ -2,4 +2,5 @@ export * from './ImportExportTranspiler';
 export * from './CubePropContextTranspiler';
 export * from './CubeCheckDuplicatePropTranspiler';
 export * from './ValidationTranspiler';
+export * from './IIFETranspiler';
 export * from './transpiler.interface';

packages/cubejs-schema-compiler/src/compiler/transpilers/transpiler_worker.ts

@@ -10,6 +10,7 @@ import { CubePropContextTranspiler } from './CubePropContextTranspiler';
 import { ErrorReporter } from '../ErrorReporter';
 import { LightweightSymbolResolver } from './LightweightSymbolResolver';
 import { LightweightNodeCubeDictionary } from './LightweightNodeCubeDictionary';
+import { IIFETranspiler } from './IIFETranspiler';
 
 type TransferContent = {
   fileName: string;
@@ -28,6 +29,7 @@ const transpilers = {
   ImportExportTranspiler: new ImportExportTranspiler(),
   CubeCheckDuplicatePropTranspiler: new CubeCheckDuplicatePropTranspiler(),
   CubePropContextTranspiler: new CubePropContextTranspiler(cubeSymbols, cubeDictionary, cubeSymbols),
+  IIFETranspiler: new IIFETranspiler(),
 };
 
 const transpile = (data: TransferContent) => {