1 files changed, 130 insertions, 0 deletions
diff --git a/dev/lint/global-declarations.js b/dev/lint/global-declarations.js
new file mode 100644
index 00000000..5448df85
--- /dev/null
+++ b/dev/lint/global-declarations.js
@@ -0,0 +1,130 @@
+/*
+ * Copyright (C) 2020  Yomichan Authors
+ * Author: Yomichan Authors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+const fs = require('fs');
+const path = require('path');
+const assert = require('assert');
+const {getAllFiles} = require('../util');
+
+
+function countOccurences(string, pattern) {
+    return (string.match(pattern) || []).length;
+}
+
+function getNewline(string) {
+    const count1 = countOccurences(string, /(?:^|[^\r])\n/g);
+    const count2 = countOccurences(string, /\r\n/g);
+    const count3 = countOccurences(string, /\r(?:[^\n]|$)/g);
+    if (count2 > count1) {
+        return (count3 > count2) ? '\r' : '\r\n';
+    } else {
+        return (count3 > count1) ? '\r' : '\n';
+    }
+}
+
+function getSubstringCount(string, substring) {
+    let start = 0;
+    let count = 0;
+    while (true) {
+        const pos = string.indexOf(substring, start);
+        if (pos < 0) { break; }
+        ++count;
+        start = pos + substring.length;
+    }
+    return count;
+}
+
+
+function validateGlobals(fileName, fix) {
+    const pattern = /\/\*\s*global\s+([\w\W]*?)\*\//g;
+    const trimPattern = /^[\s,*]+|[\s,*]+$/g;
+    const splitPattern = /[\s,*]+/;
+    const source = fs.readFileSync(fileName, {encoding: 'utf8'});
+    let match;
+    let first = true;
+    let endIndex = 0;
+    let newSource = '';
+    const allGlobals = [];
+    const newline = getNewline(source);
+    while ((match = pattern.exec(source)) !== null) {
+        if (!first) {
+            console.error(`Encountered more than one global declaration in ${fileName}`);
+            return false;
+        }
+        first = false;
+
+        const parts = match[1].replace(trimPattern, '').split(splitPattern);
+        parts.sort();
+
+        const actual = match[0];
+        const expected = `/* global${parts.map((v) => `${newline} * ${v}`).join('')}${newline} */`;
+
+        try {
+            assert.strictEqual(actual, expected);
+        } catch (e) {
+            console.error(`Global declaration error encountered in ${fileName}:`);
+            console.error(e.message);
+            if (!fix) {
+                return false;
+            }
+        }
+
+        newSource += source.substring(0, match.index);
+        newSource += expected;
+        endIndex = match.index + match[0].length;
+
+        allGlobals.push(...parts);
+    }
+
+    newSource += source.substring(endIndex);
+
+    // This is an approximate check to see if a global variable is unused.
+    // If the global appears in a comment, string, or similar, the check will pass.
+    let errorCount = 0;
+    for (const global of allGlobals) {
+        if (getSubstringCount(newSource, global) <= 1) {
+            console.error(`Global variable ${global} appears to be unused in ${fileName}`);
+            ++errorCount;
+        }
+    }
+
+    if (fix) {
+        fs.writeFileSync(fileName, newSource, {encoding: 'utf8'});
+    }
+
+    return errorCount === 0;
+}
+
+
+function main() {
+    const fix = (process.argv.length >= 2 && process.argv[2] === '--fix');
+    const directory = path.resolve(__dirname, '..', '..', 'ext');
+    const pattern = /\.js$/;
+    const ignorePattern = /[\\/]ext[\\/]mixed[\\/]lib[\\/]/;
+    const fileNames = getAllFiles(directory, null, (f) => pattern.test(f) && !ignorePattern.test(f));
+    for (const fileName of fileNames) {
+        if (!validateGlobals(fileName, fix)) {
+            process.exit(-1);
+            return;
+        }
+    }
+    process.exit(0);
+}
+
+
+if (require.main === module) { main(); }