Forbid non-ASCII characters in JS files

.eslintrc.yml

@@ -20,6 +20,7 @@ rules:
   # See './resources/eslint-internal-rules/README.md'
   ##############################################################################
 
+  internal-rules/only-ascii: error
   internal-rules/no-dir-import: error
 
   ##############################################################################
@@ -681,6 +682,7 @@ overrides:
       no-console: off
   - files: 'benchmark/**'
     rules:
+      internal-rules/only-ascii: [error, { allowEmoji: true }]
       node/no-sync: off
       node/no-missing-require: off
       import/no-nodejs-modules: off
@@ -689,6 +691,7 @@ overrides:
       no-await-in-loop: off
   - files: 'resources/**'
     rules:
+      internal-rules/only-ascii: [error, { allowEmoji: true }]
       node/no-unpublished-require: off
       node/no-sync: off
       import/no-extraneous-dependencies: [error, { devDependencies: true }]

benchmark/benchmark.js

@@ -249,7 +249,7 @@ async function runBenchmarks(benchmarks, benchmarkProjects) {
 
       if (i === 0) {
         const { name } = await sampleModule(modulePath);
-        console.log('⏱️   ' + name);
+        console.log('⏱   ' + name);
       }
 
       try {

resources/eslint-internal-rules/index.js

@@ -1,9 +1,11 @@
 'use strict';
 
+const onlyASCII = require('./only-ascii');
 const noDirImport = require('./no-dir-import');
 
 module.exports = {
   rules: {
+    'only-ascii': onlyASCII,
     'no-dir-import': noDirImport,
   },
 };

resources/eslint-internal-rules/only-ascii.js

@@ -0,0 +1,39 @@
+'use strict';
+
+module.exports = {
+  meta: {
+    schema: [
+      {
+        type: 'object',
+        properties: {
+          allowEmoji: {
+            type: 'boolean',
+          },
+        },
+        additionalProperties: false,
+      },
+    ],
+  },
+  create: onlyASCII,
+};
+
+function onlyASCII(context) {
+  const regExp =
+    context.options[0]?.allowEmoji === true
+      ? /[^\p{ASCII}\p{Emoji}]+/gu
+      : /\P{ASCII}+/gu;
+
+  return {
+    Program() {
+      const sourceCode = context.getSourceCode();
+      const text = sourceCode.getText();
+
+      for (const match of text.matchAll(regExp)) {
+        context.report({
+          loc: sourceCode.getLocFromIndex(match.index),
+          message: `Non-ASCII character "${match[0]}" found.`,
+        });
+      }
+    },
+  };
+}

resources/eslint-internal-rules/package.json

@@ -1,4 +1,8 @@
 {
   "name": "eslint-plugin-graphql-internal",
-  "version": "0.0.0"
+  "version": "0.0.0",
+  "private": true,
+  "engines": {
+    "node": ">= 14.0.0"
+  }
 }

src/language/__tests__/lexer-test.js

@@ -706,7 +706,7 @@ describe('Lexer', () => {
       message: 'Syntax Error: Invalid number, expected digit but got: "_".',
       locations: [{ line: 1, column: 2 }],
     });
-    expectSyntaxError('1ß').to.deep.equal({
+    expectSyntaxError('1\u00DF').to.deep.equal({
       message: 'Syntax Error: Cannot parse the unexpected character "\\u00DF".',
       locations: [{ line: 1, column: 2 }],
     });
@@ -718,10 +718,6 @@ describe('Lexer', () => {
       message: 'Syntax Error: Invalid number, expected digit but got: "_".',
       locations: [{ line: 1, column: 6 }],
     });
-    expectSyntaxError('1ß').to.deep.equal({
-      message: 'Syntax Error: Cannot parse the unexpected character "\\u00DF".',
-      locations: [{ line: 1, column: 2 }],
-    });
   });
 
   it('lexes punctuation', () => {