fix: do not require index sig on vars (#659)

.vscode/settings.json

@@ -8,9 +8,8 @@
   "typescript.tsdk": "node_modules/typescript/lib",
   "typescript.enablePromptUseWorkspaceTsdk": true,
   "editor.codeActionsOnSave": {
-    "source.addMissingImports": true,
-    "source.fixAll.eslint": true,
-    // Disable this because it will conflict with ESLint based import organizing.
-    "source.organizeImports": false
+    "source.addMissingImports": "explicit",
+    "source.fixAll.eslint": "explicit",
+    "source.organizeImports": "never"
   }
 }

src/classes/ClientError.ts

@@ -0,0 +1,29 @@
+import type { GraphQLRequestContext, GraphQLResponse } from '../helpers/types.js'
+
+export class ClientError extends Error {
+  public response: GraphQLResponse
+  public request: GraphQLRequestContext
+
+  constructor(response: GraphQLResponse, request: GraphQLRequestContext) {
+    const message = `${ClientError.extractMessage(response)}: ${JSON.stringify({
+      response,
+      request,
+    })}`
+
+    super(message)
+
+    Object.setPrototypeOf(this, ClientError.prototype)
+
+    this.response = response
+    this.request = request
+
+    // this is needed as Safari doesn't support .captureStackTrace
+    if (typeof Error.captureStackTrace === `function`) {
+      Error.captureStackTrace(this, ClientError)
+    }
+  }
+
+  private static extractMessage(response: GraphQLResponse): string {
+    return response.errors?.[0]?.message ?? `GraphQL Error (Code: ${response.status})`
+  }
+}