[BUG] Array field with pipe characters incorrectly parsed when using HASH data structure

[hygorchristian]

Summary

When using a string[] field type with the HASH data structure, arrays containing strings with pipe (|) characters are incorrectly split during retrieval, causing data corruption.

Environment

• redis-node version: "redis": "^5.8.2"
• redis-om version: "redis-om": "^0.4.7"
• Node.js version: v20.14.0
• Redis version: 7.4.5
• Data structure: HASH

Expected Behavior

Array fields should preserve their original structure and content when stored and retrieved, regardless of the characters contained within the strings.

Actual Behavior

Strings containing pipe (|) characters within array fields are incorrectly split at the pipe character during retrieval, corrupting the data structure.

Steps to Reproduce

1. Create a schema with a string[] field
2. Store data containing a string with a pipe character (e.g., "auth0|vVFy3-1234567")
3. Use HASH as the data structure
4. Retrieve the data

Minimal Code Example

import { Entity, Schema, Repository } from 'redis-om';

// Define schema with string array field
const userSchema = new Schema('User', {
  metadata: { type: 'string[]' }
}, {
  dataStructure: 'HASH'
});

// Create repository
const userRepository = new Repository(userSchema, client);

// Test data with pipe character
const testData = {
  metadata: ['{"meta":{"userId":"auth0|vVFy3-1234567"}}']
};

// Store and retrieve
const user = userRepository.createEntity(testData);
await userRepository.save(user);
const retrieved = await userRepository.fetch(user.entityId);

console.log('Original:', testData.metadata);
console.log('Retrieved:', retrieved.metadata);

Actual vs Expected Output

Data stored in Redis:

{"meta":{"userId":"auth0|vVFy3-1234567"}}

Expected retrieval:

["{\"meta\":{\"userId\":\"auth0|vVFy3-1234567\"}}"]

Actual retrieval (corrupted):

["{\"meta\":{\"userId\":\"auth0","vVFy3-1234567\"}}"]

Root Cause Analysis

The issue appears to be related to how redis-om parses array fields when using the HASH data structure. It seems to be using the pipe character (|) as a delimiter for array elements, which conflicts with pipe characters that are part of the actual data content.

Workaround

The issue does not occur when using the JSON data structure:

const userSchema = new Schema('User', {
  metadata: { type: 'string[]' }
}, {
  dataStructure: 'JSON'  // Works correctly
});

However, this workaround is not viable for environments where the Redis JSON module is not available.