From f56a1c278e4241bbbdab280402ac8d4350b9e584 Mon Sep 17 00:00:00 2001
From: Ib Green <ib@unfolded.ai>
Date: Mon, 3 Aug 2026 11:10:30 -0400
Subject: [PATCH] Prune inlined WebGL constant imports

---
 .../index.ts                                  | 83 ++++++++++++++++++-
 ...s-transform-inline-webgl-constants.spec.ts | 56 +++++++++++++
 2 files changed, 138 insertions(+), 1 deletion(-)

diff --git a/modules/ts-plugins/src/ts-transform-inline-webgl-constants/index.ts b/modules/ts-plugins/src/ts-transform-inline-webgl-constants/index.ts
index 4aa4b6a..69f9576 100644
--- a/modules/ts-plugins/src/ts-transform-inline-webgl-constants/index.ts
+++ b/modules/ts-plugins/src/ts-transform-inline-webgl-constants/index.ts
@@ -14,6 +14,12 @@ import type {Program, TransformationContext, SourceFile, Node} from 'typescript'
 import type {TransformerExtras, PluginConfig} from 'ts-patch';
 import {GL} from '@luma.gl/constants';
 
+const WEBGL_CONSTANT_MODULES = new Set([
+  '@luma.gl/constants',
+  '@luma.gl/webgl/constants',
+  'luma.gl/constants'
+]);
+
 export default function (program: Program, pluginConfig: PluginConfig, {ts}: TransformerExtras) {
   return (ctx: TransformationContext) => {
     const {factory} = ctx;
@@ -25,6 +31,9 @@ export default function (program: Program, pluginConfig: PluginConfig, {ts}: Tra
 
     return (sourceFile: SourceFile) => {
       function visit(node: Node): Node {
+        if (ts.isImportDeclaration(node)) {
+          return node;
+        }
         if (ts.isPropertyAccessExpression(node) && filterLeftIdentifier(node)) {
           const key = node.getChildAt(2);
           if (ts.isIdentifier(key) && key.text in GL) {
@@ -39,7 +48,79 @@ export default function (program: Program, pluginConfig: PluginConfig, {ts}: Tra
         }
         return ts.visitEachChild(node, visit, ctx);
       }
-      return ts.visitNode(sourceFile, visit);
+
+      const transformedSourceFile = ts.visitEachChild(sourceFile, visit, ctx);
+      const runtimeIdentifiers = getRuntimeIdentifiers(transformedSourceFile);
+
+      const statements = transformedSourceFile.statements.flatMap((statement) => {
+        if (!ts.isImportDeclaration(statement) || !isWebGLConstantsImport(statement)) {
+          return [statement];
+        }
+
+        const importClause = statement.importClause;
+        const namedBindings = importClause?.namedBindings;
+        if (!importClause || !namedBindings || !ts.isNamedImports(namedBindings)) {
+          return [statement];
+        }
+
+        const elements = namedBindings.elements.filter((element) =>
+          runtimeIdentifiers.has(element.name.text)
+        );
+        if (elements.length === namedBindings.elements.length) {
+          return [statement];
+        }
+        if (!elements.length && !importClause.name) {
+          return [];
+        }
+
+        const updatedNamedBindings = elements.length
+          ? factory.updateNamedImports(namedBindings, elements)
+          : undefined;
+        const updatedImportClause = factory.updateImportClause(
+          importClause,
+          importClause.isTypeOnly,
+          importClause.name,
+          updatedNamedBindings
+        );
+        return [
+          factory.updateImportDeclaration(
+            statement,
+            statement.modifiers,
+            updatedImportClause,
+            statement.moduleSpecifier,
+            statement.assertClause
+          )
+        ];
+      });
+
+      return factory.updateSourceFile(transformedSourceFile, statements);
+
+      function getRuntimeIdentifiers(node: Node): Set<string> {
+        const identifiers = new Set<string>();
+
+        collectRuntimeIdentifiers(node);
+        return identifiers;
+
+        function collectRuntimeIdentifiers(child: Node): void {
+          if (ts.isImportDeclaration(child) || ts.isTypeNode(child)) {
+            return;
+          }
+          if (ts.isIdentifier(child)) {
+            identifiers.add(child.text);
+          }
+          ts.forEachChild(child, collectRuntimeIdentifiers);
+        }
+      }
+
+      function isWebGLConstantsImport(node: Node): boolean {
+        if (ts.isImportDeclaration(node)) {
+          return (
+            ts.isStringLiteral(node.moduleSpecifier) &&
+            WEBGL_CONSTANT_MODULES.has(node.moduleSpecifier.text)
+          );
+        }
+        return false;
+      }
     };
   };
 }
diff --git a/modules/ts-plugins/test/ts-transform-inline-webgl-constants.spec.ts b/modules/ts-plugins/test/ts-transform-inline-webgl-constants.spec.ts
index aa9ee5a..04e4b49 100644
--- a/modules/ts-plugins/test/ts-transform-inline-webgl-constants.spec.ts
+++ b/modules/ts-plugins/test/ts-transform-inline-webgl-constants.spec.ts
@@ -7,6 +7,8 @@ const testCases = [
   {
     title: 'drop GL import',
     input: `\
+import {GL} from '@luma.gl/webgl/constants';
+
 device.setParametersWebGL({
   blendFunc: [GL.ONE, GL.ONE_MINUS_DST_COLOR, GL.SRC_ALPHA, GL.DST_ALPHA]
 });
@@ -15,6 +17,60 @@ device.setParametersWebGL({
 device.setParametersWebGL({
   blendFunc: [1, 775, 770, 772]
 });
+export {};
+`
+  },
+  {
+    title: 'retain other named imports',
+    input: `\
+import {GL, OTHER_CONSTANT} from '@luma.gl/webgl/constants';
+
+console.log(GL.TRIANGLES, OTHER_CONSTANT);
+`,
+    output: `\
+import { OTHER_CONSTANT } from '@luma.gl/webgl/constants';
+console.log(4, OTHER_CONSTANT);
+`
+  },
+  {
+    title: 'retain GL import for dynamic access',
+    input: `\
+import {GL} from '@luma.gl/webgl/constants';
+
+const name = 'TRIANGLES';
+console.log(GL[name]);
+`,
+    output: `\
+import { GL } from '@luma.gl/webgl/constants';
+const name = 'TRIANGLES';
+console.log(GL[name]);
+`
+  },
+  {
+    title: 'retain GL import for direct access',
+    input: `\
+import {GL} from '@luma.gl/webgl/constants';
+
+console.log(GL);
+`,
+    output: `\
+import { GL } from '@luma.gl/webgl/constants';
+console.log(GL);
+`
+  },
+  {
+    title: 'drop GL import when remaining references are types',
+    input: `\
+import {GL, GLPrimitiveTopology, type GLTextureTarget} from '@luma.gl/webgl/constants';
+
+export function getTriangleMode(topology: GLPrimitiveTopology): GLTextureTarget | GL.TRIANGLES {
+  return GL.TRIANGLES;
+}
+`,
+    output: `\
+export function getTriangleMode(topology) {
+  return 4;
+}
 `
   },
   {