Add tsOnlyTest to ruleTester.ts to allow testing TS only syntax.

Author: joshwilsonvu

test/ruleTester.ts

@@ -20,8 +20,8 @@ const jsxTester = new RuleTester({
   },
 });
 
-// TypeScript's ESLint parser
-const tsTester = new RuleTester({
+// spread ...tsOnlyTest into a test case to enforce it always runs with the TS parser
+export const tsOnlyTest: Pick<TSESLint.RuleTesterConfig, "parser" | "parserOptions"> = {
   parser: require.resolve("@typescript-eslint/parser"),
   parserOptions: {
     ecmaVersion: 2018,
@@ -30,7 +30,11 @@ const tsTester = new RuleTester({
       jsx: true,
     },
   },
-});
+};
+
+// TypeScript's ESLint parser
+const tsTester = new RuleTester(tsOnlyTest);
+
 // Babel's ESLint parser
 const babelTester = new RuleTester({
   parser: require.resolve("@babel/eslint-parser"),

test/rules/imports.test.ts

@@ -1,4 +1,4 @@
-import { run } from "../ruleTester";
+import { run, tsOnlyTest } from "../ruleTester";
 import rule from "../../src/rules/imports";
 
 export const cases = run("imports", rule, {
@@ -15,7 +15,7 @@ export const cases = run("imports", rule, {
     {
       code: `import type { Component, JSX } from "solid-js";
 import type { Store } from "solid-js/store";`,
-      parser: require.resolve("@typescript-eslint/parser"),
+      ...tsOnlyTest,
     },
   ],
   invalid: [
@@ -56,7 +56,7 @@ console.log('hi');`,
       output: `
 import { createSignal, Component } from "solid-js";
 console.log('hi');`,
-      parser: require.resolve("@typescript-eslint/parser"),
+      ...tsOnlyTest,
     },
     {
       code: `import { createSignal } from "solid-js/web";

test/rules/no-destructure.test.ts

@@ -1,4 +1,4 @@
-import { run } from "../ruleTester";
+import { run, tsOnlyTest } from "../ruleTester";
 import rule from "../../src/rules/no-destructure";
 
 export const cases = run("no-destructure", rule, {
@@ -37,7 +37,7 @@ export const cases = run("no-destructure", rule, {
     `let element = <div />`, // parse top level JSX
     {
       code: `let Component = (props: Props) => <div />;`,
-      parser: require.resolve("@typescript-eslint/parser"),
+      ...tsOnlyTest,
     },
   ],
   invalid: [
@@ -246,9 +246,9 @@ various();
     },
     {
       code: `let Component = ({ prop1, prop2 }: Props) => <div p1={prop1} p2={prop2} />;`,
-      parser: require.resolve("@typescript-eslint/parser"),
       errors: [{ messageId: "noDestructure" }],
       output: `let Component = (props: Props) => <div p1={props.prop1} p2={props.prop2} />;`,
+      ...tsOnlyTest,
     },
   ],
 });