add eslint@9 support and flat config (#3942)

Author: dartess

.changeset/perfect-fans-hammer.md

@@ -0,0 +1,5 @@
+---
+"eslint-plugin-mobx": patch
+---
+
+add eslint@9 support and flat config

packages/eslint-plugin-mobx/README.md

@@ -10,6 +10,8 @@ npm install --save-dev eslint @typescript-eslint/parser eslint-plugin-mobx
 
 ## Configuration
 
+### Legacy Config
+
 ```javascript
 // .eslintrc.js
 module.exports = {
@@ -24,12 +26,37 @@ module.exports = {
         "mobx/exhaustive-make-observable": "warn",
         "mobx/unconditional-make-observable": "error",
         "mobx/missing-make-observable": "error",
-        "mobx/missing-observer": "warn",
-        "mobx/no-anonymous-observer": "warn"
+        "mobx/missing-observer": "warn"
     }
 }
 ```
 
+### Flat Config
+
+```javascript
+// eslint.config.js
+import pluginMobx from "eslint-plugin-mobx"
+
+export default [
+    // ...
+
+    // Either extend our recommended configuration:
+    pluginMobx.flatConfigs.recommended,
+
+    // ...or specify and customize individual rules:
+    {
+        plugins: { mobx: pluginMobx },
+        rules: {
+            // these values are the same as recommended
+            "mobx/exhaustive-make-observable": "warn",
+            "mobx/unconditional-make-observable": "error",
+            "mobx/missing-make-observable": "error",
+            "mobx/missing-observer": "warn"
+        }
+    }
+]
+```
+
 ## Rules
 
 ### mobx/exhaustive-make-observable

packages/eslint-plugin-mobx/__tests__/exhaustive-make-observable.js

@@ -1,11 +1,8 @@
-import { RuleTester } from "eslint";
+import { getRuleTester } from "./utils/get-rule-tester";
 
 import rule from "../src/exhaustive-make-observable.js";
 
-const tester = new RuleTester({
-  parser: require.resolve('@typescript-eslint/parser'),
-  parserOptions: {}
-});
+const tester = getRuleTester();
 
 const decoratedFields = [
   '@observable o = 5',

packages/eslint-plugin-mobx/__tests__/missing-make-observable.js

@@ -1,11 +1,8 @@
-import { RuleTester } from "eslint";
+import { getRuleTester } from "./utils/get-rule-tester";
 
 import rule from "../src/missing-make-observable.js";
 
-const tester = new RuleTester({
-  parser: require.resolve('@typescript-eslint/parser'),
-  parserOptions: {}
-});
+const tester = getRuleTester();
 
 const fields = [
   '@observable o = 5',

packages/eslint-plugin-mobx/__tests__/missing-observer.js

@@ -1,11 +1,8 @@
-import { RuleTester } from "eslint"
+import { getRuleTester } from "./utils/get-rule-tester";
 
 import rule from "../src/missing-observer.js"
 
-const tester = new RuleTester({
-    parser: require.resolve("@typescript-eslint/parser"),
-    parserOptions: {}
-})
+const tester = getRuleTester();
 
 const valids = [
     "observer(function Named() { });",

packages/eslint-plugin-mobx/__tests__/no-anonymous-observer.js

@@ -1,11 +1,8 @@
-import { RuleTester } from "eslint"
+import { getRuleTester } from "./utils/get-rule-tester";
 
 import rule from "../src/no-anonymous-observer.js"
 
-const tester = new RuleTester({
-    parser: require.resolve("@typescript-eslint/parser"),
-    parserOptions: {}
-})
+const tester = getRuleTester();
 
 const valids = ["observer(function Name() {})", "observer(class Name {})"]
 

packages/eslint-plugin-mobx/__tests__/unconditional-make-observable.js

@@ -1,11 +1,8 @@
-import { RuleTester } from "eslint";
+import { getRuleTester } from "./utils/get-rule-tester";
 
 import rule from "../src/unconditional-make-observable.js";
 
-const tester = new RuleTester({
-  parser: require.resolve('@typescript-eslint/parser'),
-  parserOptions: {}
-});
+const tester = getRuleTester();
 
 const valid1 = {
   code: `

packages/eslint-plugin-mobx/__tests__/utils/get-rule-tester.js

@@ -0,0 +1,29 @@
+const version = global.ESLINT_V;
+
+const { RuleTester } = require(`eslint-${version}`);
+const typescriptEslintParser = require("@typescript-eslint/parser");
+
+function getRuleTesterConfig() {
+    switch (version) {
+        case 7:
+            return {
+                parser: require.resolve("@typescript-eslint/parser"),
+                parserOptions: {},
+            };
+        case 9:
+            return {
+                languageOptions: {
+                    parser: typescriptEslintParser,
+                    parserOptions: {},
+                },
+            };
+        default:
+            throw new Error(`Unknown or unspecified ESLINT_V (${String(version)})`);
+    }
+}
+
+function getRuleTester() {
+    return new RuleTester(getRuleTesterConfig());
+}
+
+export { getRuleTester }

packages/eslint-plugin-mobx/jest.config-eslint-7.js

@@ -0,0 +1,10 @@
+const buildConfig = require("../../jest.base.config")
+
+module.exports = buildConfig(__dirname, {
+    displayName: 'eslint-plugin-mobx with eslint@7',
+    setupFilesAfterEnv: ["<rootDir>/jest.setup.js"],
+    testRegex: "__tests__/[^/]+\\.(t|j)sx?$",
+    globals: {
+        ESLINT_V: 7
+    }
+})

packages/eslint-plugin-mobx/jest.config-eslint-9.js

@@ -0,0 +1,10 @@
+const buildConfig = require("../../jest.base.config")
+
+module.exports = buildConfig(__dirname, {
+    displayName: 'eslint-plugin-mobx with eslint@9',
+    setupFilesAfterEnv: ["<rootDir>/jest.setup.js"],
+    testRegex: "__tests__/[^/]+\\.(t|j)sx?$",
+    globals: {
+        ESLINT_V: 9
+    }
+})