TypeScript Postgres Error Handling

with-pg-error-handling.ts

import { DatabaseError } from "pg";
import { DatabaseErrorCode } from "./errors";

/**
 * Higher order function with fine-grained error handling.
 */
export async function withErrorHandling<T>(
  fn: () => Promise<T>,
  onError: Record<string, (error: PgDatabaseError) => void>,
) {
  try {
    return await fn();
  } catch (error) {
    if (!(error instanceof PgDatabaseError)) {
      throw error;
    }

    onError[error.code as string]?.(error);
  }
}

export async function createUser(params: typeof users.$inferInsert) {
  return withErrorHandling(
    async () => {
      const [created] = await db
        .insert(users)
        .values(params)
        .returning();

      if (!created) {
        throw new ResourceCreationError("user");
      }

      return created;
    },
    {
      [DatabaseErrorCode.UniqueViolation]: (error) => {
        throw new ResourceConflictError("That email address is taken", error);
      },
    },
  );
}