fix: Cannot export a block as a reserved namespace identifier.

Author: chriseppstein

packages/@css-blocks/core/src/BlockParser/features/export-blocks.ts

@@ -1,6 +1,6 @@
 import { postcss } from "opticss";
 
-import { BLOCK_EXPORT, CLASS_NAME_IDENT, DEFAULT_EXPORT } from "../../BlockSyntax";
+import { BLOCK_EXPORT, CLASS_NAME_IDENT, DEFAULT_EXPORT, RESERVED_BLOCK_NAMES } from "../../BlockSyntax";
 import { Block } from "../../BlockTree";
 import * as errors from "../../errors";
 import { sourceRange } from "../../SourceLocation";
@@ -77,7 +77,8 @@ export async function exportBlocks(block: Block, factory: BlockFactory, file: st
             sourceRange(factory.configuration, block.stylesheet, file, atRule),
           );
         }
-        if (remoteName === DEFAULT_EXPORT) {
+
+        if (RESERVED_BLOCK_NAMES.has(remoteName)) {
           throw new errors.InvalidBlockSyntax(
             `Cannot export "${localName}" as reserved word "${remoteName}"`,
             sourceRange(factory.configuration, block.stylesheet, file, atRule),

packages/@css-blocks/core/test/BlockParser/import-export-test.ts

@@ -612,6 +612,25 @@ export class BlockImportExport extends BEMProcessor {
     );
   }
 
+  @test async "svg is a reserved word – bare exports"() {
+    let imports = new MockImportRegistry();
+    imports.registerSource(
+      "images.block.css",
+      `:scope { color: red; }`,
+    );
+
+
+    let inputCSS = `
+      @export (default as svg) from "./images.block.css";
+    `;
+
+    return assertError(
+      InvalidBlockSyntax,
+      `Cannot export "default" as reserved word "svg" (test.css:2:7)`,
+      this.process("test.css", inputCSS, {importer: imports.importer()}),
+    );
+  }
+
   @test async "default is a reserved word – named exports"() {
     let imports = new MockImportRegistry();
     imports.registerSource(