Handle externals2 if present

Author: aleksanderkatan

packages/typegpu/src/core/function/fnCore.ts

@@ -3,7 +3,7 @@ import { undecorate } from '../../data/dataTypes.ts';
 import { type ResolvedSnippet, snip } from '../../data/snippet.ts';
 import { type BaseData, isWgslData, isWgslStruct, Void } from '../../data/wgslTypes.ts';
 import { MissingLinksError } from '../../errors.ts';
-import { getMetaData, getName } from '../../shared/meta.ts';
+import { getMetaData, getName, type Externals2 } from '../../shared/meta.ts';
 import { $getNameForward } from '../../shared/symbols.ts';
 import type { ResolutionCtx } from '../../types.ts';
 import { applyExternals, type ExternalMap, replaceExternalsInWgsl } from '../resolve/externals.ts';
@@ -148,11 +148,14 @@ export function createFnCore(implementation: Implementation, fnAttribute = ''):
       const pluginData = getMetaData(implementation);
 
       // Passing a record happens prior to version 0.9.0
+      // Passing a function happens prior to version 0.12.0
       // TODO: Support for this can be removed down the line
-      const pluginExternals =
-        typeof pluginData?.externals === 'function'
-          ? pluginData.externals()
-          : pluginData?.externals;
+      let pluginExternals: ExternalMap | Record<string, unknown> | undefined =
+        pluginData?.externals2
+          ? externals2ToExternalMap(pluginData.externals2)
+          : typeof pluginData?.externals === 'function'
+            ? pluginData.externals()
+            : pluginData?.externals;
 
       if (pluginExternals) {
         const missing = Object.fromEntries(
@@ -220,6 +223,22 @@ export function createFnCore(implementation: Implementation, fnAttribute = ''):
   return core;
 }
 
+// TODO: deslopify, document, make sure it works as intended
+function externals2ToExternalMap(ext2: Externals2): ExternalMap {
+  const result: ExternalMap = {};
+  for (const [key, value] of Object.entries(ext2)) {
+    if (typeof value === 'function') {
+      Object.defineProperty(result, key, {
+        get: value,
+        enumerable: true,
+      });
+    } else {
+      result[key] = externals2ToExternalMap(value);
+    }
+  }
+  return result;
+}
+
 function isArgUsedInBody(argName: string, body: string): boolean {
   return new RegExp(`\\b${argName}\\b`).test(body);
 }

packages/typegpu/src/shared/meta.ts

@@ -8,6 +8,10 @@ export interface Externals {
   [key: string]: Externals | string;
 }
 
+export interface Externals2 {
+  [key: string]: Externals2 | (() => unknown);
+}
+
 export interface MetaData {
   v?: number;
   name?: string | undefined;
@@ -22,6 +26,7 @@ export interface MetaData {
     // Passing a record happens prior to version 0.9.0
     // TODO: Support for this can be removed down the line
     Record<string, unknown> | (() => Record<string, unknown>) | undefined;
+  externals2?: Externals2;
 }
 
 /**