Easylist to Adblock Script

[jhreis]

Rules come to us in the format:

"text","count"
"||01net.com/track/",118
"/0/ads/*",10
"_120_60.",29
"_120_600_",1
"_120_600.",3
"/120_600.",39
"_120x240.",1
"-120x240.",31

And need to be massaged into a format that the iOS content blocking extension API wants:

e.g.

{
    "trigger": {
        "url-filter": "^[^:]+:(//)?.*/[0i]/ads/",
        "resource-type": [
            "image",
            "style-sheet",
            "script",
            "font",
            "media",
            "raw"
        ]
    },
    "action": {
        "type": "block"
    }
},

This adblockplus script does a decent job but is still shy of what is needed. More specifically, the writeup that @kylehickinson created (copied verbatim):

Library issues:

• Doesn't deal with exception/ignore rules (prefixed: @@||)

  • Creates a rule with the url-filter literally containing escaped @@|| characters

• Doesn't deal with items that are surrounded with quotes ("{rule}")

  • Creates a rule with the url-filter literally containing quotes

• When no type is provided I would assume resource-type could be omitted instead of including most of the types. Maybe there's a reason for this?

  • Creates a rule with the following resource-types: "image", "style-sheet", "script", "font", "media", and "raw". Missing: "document", "svg-document"

• Rules with wildcard suffixes don't generate regex for it? /0/ads/* -> ^[^:]+:(//)?.*/[0i]/ads/

  • Shouldn't it be ^[^:]+:(//)?.*/[0i]/ads/.+ or at least ^[^:]+:(//)?.*/[0i]/ads/.*. On top of that, what's with the [0i]? Isn't /0/ads/.+ enough?

• Not sure how it handles CSS because our subset of rules doesn't include any (further testing required)

• It seems to be applying case-sensitivity based on the use of a separator character? ||quantcount.com^$third-party creates this:

  {
    "trigger": {
      "url-filter": "^[^:]+:(//)?([^/]+\\.)?quantcount\\.com([^-_.%a-z0-9].*)?$",
      "url-filter-is-case-sensitive": true,
      "resource-type": [
        "image",
        "style-sheet",
        "script",
        "font",
        "media",
        "raw",
        "document"
      ],
      "load-type": [
        "third-party"
      ],
      "unless-top-url": [
        "^[^:]+:(//)?([^/]+\\.)?quantcount\\.com([^-_.%a-z0-9].*)?$"
      ],
      "top-url-filter-is-case-sensitive": true
    },
    "action": {
      "type": "block"
    }
  }

  Expected:

  {
    "trigger": {
      "url-filter": "^[^:]+:(//)?([^/]+\\.)?quantcount\\.com$",
      "load-type": [
        "third-party"
      ],
      "unless-top-url": [
        "[^:]+:(//)?([^/]+\\.)?quantcount\\.com"
      ]
    },
    "action": {
      "type": "block"
    }
  }

---

Other resources:
adblock rule format explainer
adblock static ruleset
Apple format docs

[jhreis]

Fixed per: https://github.com/brave/ab2cb