I use Dawn and I’ve made a few changes to my theme (add whatsapp icon to Social Media icons, script to hide empty collapsible row, add video icon as an option on the collapsible row).
When I update Dawn these changes are lost. Is there a way, other than manually adding the code every time I update the theme, to keep this custom code when updating the theme?
Whenever you update a theme, there are coding that the updated theme does not support this is why. However, whenever you are going to update the original version of the theme will still be added on your theme library, so you do not need to worry about the theme codes to be lost.
I use Dawn myself and have run into the same problem. Your existing customized theme remains available after the update, but that doesn’t transfer its customizations into the new Dawn version.
Where possible, it helps to keep custom code in separate snippets or asset files. However, changes made directly to existing Dawn files still need to be checked with every update. Simply copying the old modified files into the new version isn’t safe, because that could overwrite changes Shopify introduced in the updated theme.
This exact issue with Dawn led me to create a paid Theme Update Audit. It compares your customized theme ZIP with the updated version and identifies which changes are present, missing, partial, or conflicting. In your case, this would include changes such as the WhatsApp icon and the additional collapsible-row behavior.
The audit includes guidance on what needs to be addressed. More details are available in this Ask & Offer post: Theme Update Audit for Custom Code
Ralf’s split is the right one: custom code kept in its own snippets and assets survives an update, edits made inside Dawn’s own files never do, and copying old files over the new version is how people break the update itself. What makes the re-apply step bearable is knowing exactly which files you touched. The code editor marks edited templates and sections, but not CSS or JS assets, and the marks do not survive a duplicate.
A versioned copy of the theme solves that half. Compare the current version with the one from before your first edit and you get the list: these seven files differ, here is what changed in each. Reapplying after an update becomes seven targeted edits instead of a hunt through three hundred files.
StoreVault keeps daily versions of every theme file, and since this week it can write files back into the theme they came from. That covers the other failure in this thread’s family: you updated, something broke, and you want yesterday’s files back in that theme without touching the new one. Publishing stays yours; we never publish a theme.
The safest approach is to duplicate the current theme, install a fresh copy of the new Dawn version, then compare and re-apply only your custom changes. Avoid copying entire old theme files over the new version, since that can overwrite Shopify’s updates. If you want, I can help you identify which custom files need to be migrated safely.