Add testcase for d flag (#64)

Author: ota-meshi

tests/lib/rules-with-d-flag.ts

@@ -0,0 +1,34 @@
+import { Linter } from "eslint"
+import * as parser from "@typescript-eslint/parser"
+// @ts-expect-error -- ignore
+import { rules } from "../../lib/index"
+import assert from "assert"
+
+describe("Don't crash even if with d flag.", () => {
+    const code = "var foo = /a/d; new RegExp('a', 'd')"
+
+    for (const key of Object.keys(rules)) {
+        const rule = rules[key]
+        const ruleId = rule.meta.docs.ruleId
+
+        it(ruleId, () => {
+            const linter = new Linter()
+            const config: Linter.Config = {
+                parser: "@typescript-eslint/parser",
+                parserOptions: {
+                    ecmaVersion: 2020,
+                },
+                rules: {
+                    [ruleId]: "error",
+                },
+            }
+            // @ts-expect-error -- ignore
+            linter.defineParser("@typescript-eslint/parser", parser)
+            // @ts-expect-error -- ignore
+            linter.defineRule(ruleId, rule)
+            const resultVue = linter.verifyAndFix(code, config, "test.js")
+
+            assert.deepStrictEqual(resultVue.messages, [])
+        })
+    }
+})