fix(rsc): attach positions to string export errors

Co-authored-by: Codex <noreply@openai.com>

Author: hi-ogawa

packages/plugin-rsc/src/transforms/expand-export-all.ts

@@ -148,7 +148,10 @@ function collectExplicitExportNames(ast: Program): Set<string> {
           if (spec.exported.type === 'Identifier') {
             names.add(spec.exported.name)
           } else {
-            throw new Error('unsupported string literal export name')
+            throw Object.assign(
+              new Error('unsupported string literal export name'),
+              { pos: spec.exported.start },
+            )
           }
         }
       }

packages/plugin-rsc/src/transforms/proxy-export.ts

@@ -107,7 +107,10 @@ export function transformProxyExport(
         const names: string[] = []
         for (const spec of node.specifiers) {
           if (spec.exported.type !== 'Identifier') {
-            throw new Error('unsupported string literal export name')
+            throw Object.assign(
+              new Error('unsupported string literal export name'),
+              { pos: spec.exported.start },
+            )
           }
           names.push(spec.exported.name)
         }

packages/plugin-rsc/src/transforms/wrap-export.ts

@@ -147,7 +147,10 @@ export function transformWrapExport(
           for (const spec of node.specifiers) {
             tinyassert(spec.local.type === 'Identifier')
             if (spec.exported.type !== 'Identifier') {
-              throw new Error('unsupported string literal export name')
+              throw Object.assign(
+                new Error('unsupported string literal export name'),
+                { pos: spec.exported.start },
+              )
             }
             const name = spec.local.name
             toAppend.push(
@@ -163,7 +166,10 @@ export function transformWrapExport(
           for (const spec of node.specifiers) {
             tinyassert(spec.local.type === 'Identifier')
             if (spec.exported.type !== 'Identifier') {
-              throw new Error('unsupported string literal export name')
+              throw Object.assign(
+                new Error('unsupported string literal export name'),
+                { pos: spec.exported.start },
+              )
             }
             wrapExport(spec.local.name, spec.exported.name)
           }