Add module to extract the domain name from a given hostname

.gitignore

@@ -1,2 +1,3 @@
-/node_modules/
 /*.zip
+/node_modules/
+/public_suffix_list.dat

bin/generate-pslrules

@@ -0,0 +1,46 @@
+#!/bin/bash
+
+set -o errexit -o nounset -o pipefail -o xtrace
+
+SCRIPT_DIRECTORY=$( cd "$( dirname "${BASH_SOURCE:-$0}" )" && pwd )
+ROOT_DIRECTORY=$(realpath $SCRIPT_DIRECTORY/../)
+
+PSL_FILE="public_suffix_list.dat"
+PSL_RULES="pslrules.js"
+PSL_FILE_PATH=$ROOT_DIRECTORY/$PSL_FILE
+PSL_RULES_PATH=$ROOT_DIRECTORY/$PSL_RULES
+
+if [ ! -f $PSL_FILE_PATH ]; then
+    wget --directory-prefix $ROOT_DIRECTORY https://publicsuffix.org/list/$PSL_FILE
+fi
+
+CONTENT=$(cat << END
+const pslrules = (function(root) { //  eslint-disable-line no-unused-vars
+
+    const EXCEPTION_ENTRIES = new Set([
+$(cat $PSL_FILE_PATH | grep '^!'  | sed -e 's/^!//'                                | awk '{print $1}' | sed -e 's/\(.*\)/        "\1",/')
+    ]);
+
+    const WILDCARD_ENTRIES = new Set([
+$(cat $PSL_FILE_PATH | grep '^*.' | sed -e 's/^\*\.//'                             | awk '{print $1}' | sed -e 's/\(.*\)/        "\1",/')
+    ]);
+
+    const NORMAL_ENTRIES = new Set([
+$(cat $PSL_FILE_PATH | grep -v '^//' | grep -v '^$' | grep -v '^!' | grep -v '^*.' | awk '{print $1}' | sed -e 's/\(.*\)/        "\1",/')
+    ]);
+
+    root.EXCEPTION_ENTRIES = EXCEPTION_ENTRIES;
+    root.WILDCARD_ENTRIES = WILDCARD_ENTRIES;
+    root.NORMAL_ENTRIES = NORMAL_ENTRIES;
+
+    return {
+        EXCEPTION_ENTRIES: EXCEPTION_ENTRIES,
+        WILDCARD_ENTRIES: WILDCARD_ENTRIES,
+        NORMAL_ENTRIES: NORMAL_ENTRIES,
+    };
+
+})(this);
+END
+)
+
+echo "$CONTENT" > $PSL_RULES_PATH

package.json

@@ -4,6 +4,7 @@
         "eslint": "4.1.x",
         "jscs": "2.6.x",
         "tape": "4.6.x",
+        "tape-benchmark": "0.0.0",
         "web-ext": "1.9.x"
     },
     "license": "MIT",
@@ -31,8 +32,8 @@
         "start": "GTK_THEME=Greybird web-ext run --verbose --firefox firefox-trunk --url $(jq --raw-output '.homepage_url' manifest.json)",
         "start:german": "GTK_THEME=Greybird web-ext run --verbose --firefox firefox --pref=general.useragent.locale=de-DE --pref=intl.locale.matchOS=false --url $(jq --raw-output '.homepage_url' manifest.json)",
         "start:stable": "GTK_THEME=Greybird web-ext run --verbose --firefox firefox --url $(jq --raw-output '.homepage_url' manifest.json)",
-        "translation-check": "./bin/translation-check",
-        "test": "web-ext lint && tape $(find . -not -path '*node_modules*' -name 'test-*.js') && npm run translation-check"
+        "test": "web-ext lint && tape $(find . -not -path '*node_modules*' -name 'test-*.js') && npm run translation-check",
+        "translation-check": "./bin/translation-check"
     },
     "title": "Skip Redirect",
     "version": "2.1.7"

psl.js

@@ -0,0 +1,41 @@
+/* global pslrules */
+const psl = (function(root) { //  eslint-disable-line no-unused-vars
+
+    if (typeof pslrules === "undefined") {
+        pslrules = require("./pslrules"); //  eslint-disable-line no-global-assign,no-unused-vars
+    }
+
+    function getDomain(hostname, previousHead=undefined) {
+        if (!hostname) {
+            return undefined;
+        }
+
+        if (pslrules.EXCEPTION_ENTRIES.has(hostname)) {
+            return hostname;
+        }
+
+        let dotIndex = hostname.indexOf(".");
+        if (dotIndex == -1) {
+            return undefined;
+        }
+
+        let head = hostname.slice(0, dotIndex);
+        let rest = hostname.slice(dotIndex + 1);
+
+        if (pslrules.WILDCARD_ENTRIES.has(rest) && previousHead) {
+            return [previousHead, head, rest].join(".");
+        }
+        if (pslrules.NORMAL_ENTRIES.has(rest)) {
+            return [head, rest].join(".");
+        }
+
+        return getDomain(rest, head);
+    }
+
+    root.getDomain = getDomain;
+
+    return {
+        getDomain: getDomain,
+    };
+
+})(this);