Convert no-any-union from TSLint to ESLint

packages/dtslint/dtslint.json

@@ -9,7 +9,6 @@
         "redundant-undefined": true,
         "no-relative-import-in-test": true,
         "strict-export-declare-modifiers": true,
-        "no-any-union": true,
         "no-single-declare-module": true,
         "prefer-declare-function": true,
         "unified-signatures": true,

packages/dtslint/src/rules/no-any-union.ts

@@ -0,0 +1,34 @@
+import { createRule } from "../util";
+import { AST_NODE_TYPES } from "@typescript-eslint/utils";
+
+const rule = createRule({
+  name: "no-any-union",
+  defaultOptions: [],
+  meta: {
+    type: "problem",
+    docs: {
+      description: "Forbid a union to contain `any`",
+      recommended: "error",
+    },
+    messages: {
+      anyUnion: "Including `any` in a union will override all other members of the union.",
+    },
+    schema: [],
+  },
+  create(context) {
+    return {
+      // eslint-disable-next-line @typescript-eslint/naming-convention
+      TSUnionType(node) {
+        const hasAnyType = node.types.some((t) => t.type === AST_NODE_TYPES.TSAnyKeyword);
+        if (hasAnyType) {
+          context.report({
+            messageId: "anyUnion",
+            node,
+          });
+        }
+      },
+    };
+  },
+});
+
+export = rule;

packages/dtslint/test/no-any-union.test.ts

@@ -0,0 +1,23 @@
+import { ESLintUtils } from "@typescript-eslint/utils";
+
+import * as noAnyUnion from "../src/rules/no-any-union";
+
+const ruleTester = new ESLintUtils.RuleTester({
+  parser: "@typescript-eslint/parser",
+});
+
+ruleTester.run("no-any-union", noAnyUnion, {
+  invalid: [
+    {
+      code: `export const y: string | any;`,
+      errors: [
+        {
+          line: 1,
+          messageId: "anyUnion",
+        },
+      ],
+    },
+  ],
+  valid: [`export const x: any;`],
+});
+