Fix: Only reference schema transformers when they exist

packages/openapi-ts/src/plugins/@hey-api/transformers/plugin.ts

@@ -27,15 +27,18 @@ const isNodeReturnStatement = ({
 
 const schemaResponseTransformerNodes = ({
   plugin,
+  processingSchemas,
   schema,
 }: {
   plugin: HeyApiTransformersPlugin['Instance'];
+  processingSchemas: Set<string>;
   schema: IR.SchemaObject;
 }): Array<ts.Expression | ts.Statement> => {
   const identifierData = tsc.identifier({ text: dataVariableName });
   const nodes = processSchemaType({
     dataExpression: identifierData,
     plugin,
+    processingSchemas,
     schema,
   });
   // append return statement if one does not already exist
@@ -51,19 +54,25 @@ const schemaResponseTransformerNodes = ({
 const processSchemaType = ({
   dataExpression,
   plugin,
+  processingSchemas,
   schema,
 }: {
   dataExpression?: ts.Expression | string;
   plugin: HeyApiTransformersPlugin['Instance'];
+  processingSchemas: Set<string>;
   schema: IR.SchemaObject;
 }): Array<ts.Expression | ts.Statement> => {
   if (schema.$ref) {
     const selector = plugin.api.selector('response-ref', schema.$ref);
+    const selectorKey = JSON.stringify(selector);
 
     if (!plugin.getSymbol(selector)) {
       // TODO: remove
       // create each schema response transformer only once
 
+      // Mark as processing to handle recursion
+      processingSchemas.add(selectorKey);
+
       // Register symbol early to prevent infinite recursion with self-referential schemas
       const symbol = plugin.registerSymbol({
         name: buildName({
@@ -81,8 +90,13 @@ const processSchemaType = ({
       );
       const nodes = schemaResponseTransformerNodes({
         plugin,
+        processingSchemas,
         schema: refSchema,
       });
+
+      // Done processing
+      processingSchemas.delete(selectorKey);
+
       if (nodes.length) {
         const node = tsc.constVariable({
           expression: tsc.arrowFunction({
@@ -103,7 +117,9 @@ const processSchemaType = ({
       }
     }
 
-    if (plugin.isSymbolRegistered(selector)) {
+    // Only reference the symbol if it has a value (transformer function was generated)
+    // OR is currently being processed (recursive case)
+    if (plugin.hasSymbolValue(selector) || processingSchemas.has(selectorKey)) {
       const ref = plugin.referenceSymbol(selector);
       const callExpression = tsc.callExpression({
         functionName: ref.placeholder,
@@ -145,6 +161,7 @@ const processSchemaType = ({
       : processSchemaType({
           dataExpression: 'item',
           plugin,
+          processingSchemas,
           schema: schema.items?.[0]
             ? schema.items[0]
             : {
@@ -209,6 +226,7 @@ const processSchemaType = ({
       const propertyNodes = processSchemaType({
         dataExpression: propertyAccessExpression,
         plugin,
+        processingSchemas,
         schema: property,
       });
       if (!propertyNodes.length) {
@@ -245,6 +263,7 @@ const processSchemaType = ({
       return processSchemaType({
         dataExpression: 'item',
         plugin,
+        processingSchemas,
         schema: schema.items[0]!,
       });
     }
@@ -262,6 +281,7 @@ const processSchemaType = ({
         const nodes = processSchemaType({
           dataExpression: dataExpression || 'item',
           plugin,
+          processingSchemas,
           schema: item,
         });
         if (nodes.length) {
@@ -319,6 +339,9 @@ const processSchemaType = ({
 
 // handles only response transformers for now
 export const handler: HeyApiTransformersPlugin['Handler'] = ({ plugin }) => {
+  // Track schemas currently being processed to handle recursion
+  const processingSchemas = new Set<string>();
+
   plugin.forEach(
     'operation',
     ({ operation }) => {
@@ -343,6 +366,7 @@ export const handler: HeyApiTransformersPlugin['Handler'] = ({ plugin }) => {
       // TODO: parser - consider handling simple string response which is also a date
       const nodes = schemaResponseTransformerNodes({
         plugin,
+        processingSchemas,
         schema: response,
       });
       if (!nodes.length) return;

packages/openapi-ts/src/plugins/shared/utils/instance.ts

@@ -297,6 +297,11 @@ export class PluginInstance<T extends Plugin.Types = Plugin.Types> {
     return this.gen.symbols.isRegistered(symbolIdOrSelector);
   }
 
+  hasSymbolValue(symbolIdOrSelector: number | Selector): boolean {
+    const symbol = this.getSymbol(symbolIdOrSelector);
+    return symbol ? this.gen.symbols.hasValue(symbol.id) : false;
+  }
+
   referenceSymbol(symbolIdOrSelector: number | Selector): Symbol {
     return this.gen.symbols.reference(symbolIdOrSelector);
   }