Merge pull request #599 from brave/new-ubo-scriptlets-format

Update code to support new uBlock Origin scriptlets format

lib/adBlockRustUtils.js

@@ -47,14 +47,65 @@ const lazyInit = (fn) => {
   }
 }
 
+// Wraps new template scriptlets with the older "numbered template arg" format and any required dependency code
+const wrapScriptletArgFormat = (fnString, dependencyPrelude) => `{
+  const args = ['{{1}}', '{{2}}', '{{3}}', '{{4}}', '{{5}}', '{{6}}', '{{7}}', '{{8}}', '{{9}}'];
+  let last_arg_index = 0;
+  for (const arg_index in args) {
+    if (args[arg_index] === '{{' + (Number(arg_index) + 1) + '}}') {
+      break;
+    }
+    last_arg_index += 1;
+  }
+  ${dependencyPrelude}
+  (${fnString})(...args.slice(0, last_arg_index))
+}`
+
 const generateResources = lazyInit(async () => {
+  const { builtinScriptlets } = await import(path.join('..', uBlockScriptlets).toString())
+
+  const dependencyFns = builtinScriptlets.filter(s => s.name.endsWith('.fn'))
+  const dependencyMap = dependencyFns.reduce((map, entry) => {
+    map[entry.name] = entry
+    return map
+  }, {})
+
+  // ignore "trusted" scriptlets for now
+  const transformedUboBuiltins = builtinScriptlets.filter(s => !s.name.endsWith('.fn') && !s.requiresTrust).map(s => {
+    // Bundle dependencies wherever needed. This causes some small duplication but makes each scriptlet fully self-contained.
+    let dependencyPrelude = ''
+    const requiredDependencies = s.dependencies ?? []
+    for (const dep of requiredDependencies) {
+      for (const recursiveDep of dependencyMap[dep].dependencies ?? []) {
+        if (!requiredDependencies.includes(recursiveDep)) {
+          requiredDependencies.push(recursiveDep)
+        }
+      }
+    }
+    for (const dep of requiredDependencies.reverse()) {
+      const thisDepCode = dependencyMap[dep].fn.toString()
+      if (thisDepCode === undefined) {
+        throw new Error(`Couldn't find dependency ${dep}`)
+      }
+      dependencyPrelude += thisDepCode + '\n'
+    }
+    const content = Buffer.from(wrapScriptletArgFormat(s.fn.toString(), dependencyPrelude)).toString('base64')
+    return {
+      name: s.name,
+      aliases: s.aliases ?? [],
+      kind: { mime: 'application/javascript' },
+      content
+    }
+  })
+
   const resourceData = uBlockResources(
     uBlockWebAccessibleResources,
-    uBlockRedirectEngine,
-    uBlockScriptlets
+    uBlockRedirectEngine
   )
+
   const braveResources = await requestJSON(braveResourcesUrl)
   resourceData.push(...braveResources)
+  resourceData.push(...transformedUboBuiltins)
   return JSON.stringify(resourceData)
 })