Rule JSON Import/Export

The last section of the settings page displays the current custom rules as JSON. It's useful for backups, migrations, and bulk edits.

Use Cases

• Migrate custom rules across devices or browser profiles
• Back up rules with version control
• Bulk editing (search-and-replace in the text field is faster than editing row by row in the form)
• Programmatically generate a large rule set (write a script to produce the array)

Field Structure

Each rule is an object:

{
  "name": "MyCMS",
  "category": "CMS / Website Programs",
  "kind": "Custom CMS",
  "confidence": "medium",
  "matchType": "regex",
  "patterns": ["mycms-[0-9.]+\\.js", "X-Generator: MyCMS"],
  "selectors": ["[data-powered-by='mycms']"],
  "globals": ["MyCMS"],
  "matchIn": ["url", "resources", "html", "headers", "dynamic"],
  "url": "https://mycms.example.com"
}

Field	Type	Required	Description
name	string	Yes	Name shown in the popup
category	string		Category; defaults to Other Libraries
kind	string		Kind label; defaults to Custom Rule
confidence	"high" / "medium" / "low"		Defaults to medium
matchType	"keyword" / "regex"		Defaults to regex
patterns	string[]	One of three	At least one of patterns / selectors / globals must be non-empty
selectors	string[]	One of three	CSS selector list
globals	string[]	One of three	Global variable name list (window.x.y written as x.y)
matchIn	string[]		Any combination of url / resources / html / headers / dynamic; defaults to all
url	string		Must be http(s)://; may be empty

Buttons

Two buttons appear in the section header:

• Import from JSON: parses the textarea content and, if validation passes, replaces the entire custom rule list (not a merge)
• Format: re-serializes the parsed rules with JSON.stringify(rules, null, 2) for clean indentation

Backslashes in Strings

Regexes in JSON require double-escaping. To match \.js:

{
  "matchType": "regex",
  "patterns": ["\\.js$"]
}

The JSON parser reads \\ as a single \, giving the extension \.js$, which new RegExp() then interprets as an escaped dot.

Atomic Validation

The entire array is parsed before any rule is committed. If any rule has an invalid field, the whole import is rejected — there is no partial import state. The error message identifies which rule number and which field failed.

Relationship to the Form

• Form edits automatically sync to the JSON textarea
• JSON textarea edits require clicking "Import from JSON" to sync back to the internal rule list
• Clicking "Save Settings" without importing first saves the state from the last form edit or import operation

Limits

CUSTOM_RULE_LIMITS.rules defaults to 100. Exceeding it causes the import to be rejected. Full limits in src/types/settings.ts:

Field	Limit
Total rules	100
name	80 chars
category	40 chars
kind	40 chars
Single pattern / selector / global	240 chars
patterns / selectors / globals array length	80 each
matchIn array length	8
url	240 chars
customCss	10,000 chars