Bug - v1.12.17, v1.12.18, v1.12.19

Summary

Salesforce allows External ID fields to contain whitespace, but theget_by_custom_id method in Simple Salesforce currently usesquote_plus, which encodes spaces as+. This causes lookups to fail for records with spaces in their External IDs, resulting in a“Resource not found” error.

Steps to Reproduce

1. Create a record in Salesforce with an External ID containing a space:

   External ID: "My Job Name"

2. Attempt to retrieve it via:

   sf.CustomObject__c.get_by_custom_id("CustomExternal__c","My Job Name")

3. Observe the response.

Expected Behaviour

The record should be retrieved successfully using the exact External ID value ("My Job Name"), as Salesforce permits whitespace in External IDs.

Actual Behaviour

The request fails with:

Resource not found

becausequote_plus converts spaces into"+", sending the request as:

.../CustomExternal__c/My+Job+Name

instead of:

.../CustomExternal__c/My%20Job%20Name

Technical Details

Current implementation:

custom_url=urljoin(self.base_url,f'{custom_id_field}/{quote_plus(custom_id)}')

quote_plus encodes spaces as"+", which isnot equivalent to%20 in Salesforce External ID lookups.

Impact

• Historical data containing spaces in External IDs cannot be retrieved usingget_by_custom_id.
• Bulk updates or data migrations would be required to normalize these IDs, which may not be feasible.
• Any external integrations referencing existing IDs will also fail if"+" substitution is applied.

Proposed Fix

Useurllib.parse.quote instead ofquote_plus:

fromurllib.parseimportquotecustom_url=urljoin(self.base_url,f'{custom_id_field}/{quote(custom_id)}')

This approach ensures:

• Spaces are encoded as%20 (Salesforce-compatible)
• + signs already stored in Salesforce remain encoded correctly
• Backward compatibility is maintained

Workaround

Developers can bypassget_by_custom_id and query directly:

sf.query(f"SELECT Id FROM CustomObject__c WHERE CustomExternal__c = '{job_class_name}'")

However, this workaround is less efficient and deviates from intended API usage.