chore: Add eslint plugin tests (#3905)

* add tests for eslint rule missing-observer

* add tests for eslint rule no-anonymous-observer

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

@@ -0,0 +1,57 @@
+import { RuleTester } from "eslint"
+
+import rule from "../src/missing-observer.js"
+
+const tester = new RuleTester({
+    parser: require.resolve("@typescript-eslint/parser"),
+    parserOptions: {}
+})
+
+const valids = [
+    "observer(function Named() { });",
+    "const foo = observer(function Named() { })",
+    "const Anonym = observer(function () { });",
+    "const Arrow = observer(() => { });",
+    "function notCmp() { }",
+    "const notCmp = function notCmp() { }",
+    "const notCmp = function () { }",
+    "const notCmp = () => { }",
+    "class NotCmp { }",
+    "class NotCmp extends Foo { }",
+    "class NotCmp extends React.Foo { }",
+    "const Cmp = observer(class Cmp extends React.Component { })",
+    "const Cmp = observer(class Cmp extends Component { })",
+    "const Cmp = observer(class extends React.Component { })",
+    "const Cmp = observer(class extends Component { })"
+]
+
+const invalids = [
+    ["function Named() { }", "const Named = observer(function Named() { })"],
+    ["const foo = function Named() { }", "const foo = observer(function Named() { })"],
+    ["const Anonym = function () { };", "const Anonym = observer(function () { });"],
+    ["const Arrow = () => { };", "const Arrow = observer(() => { });"],
+    [
+        "class Cmp extends React.Component { }",
+        "const Cmp = observer(class Cmp extends React.Component { })"
+    ],
+    ["class Cmp extends Component { }", "const Cmp = observer(class Cmp extends Component { })"],
+    [
+        "const Cmp = class extends React.Component { }",
+        "const Cmp = observer(class extends React.Component { })"
+    ],
+    [
+        "const Cmp = class extends Component { }",
+        "const Cmp = observer(class extends Component { })"
+    ],
+    ["class extends Component { }", "observer(class extends Component { })"],
+    ["class extends React.Component { }", "observer(class extends React.Component { })"]
+]
+
+tester.run("missing-observer", rule, {
+    valid: valids.map(code => ({ code })),
+    invalid: invalids.map(([code, output]) => ({
+        code,
+        output,
+        errors: [{ messageId: "missingObserver" }]
+    }))
+})

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

@@ -0,0 +1,42 @@
+import { RuleTester } from "eslint"
+
+import rule from "../src/no-anonymous-observer.js"
+
+const tester = new RuleTester({
+    parser: require.resolve("@typescript-eslint/parser"),
+    parserOptions: {}
+})
+
+const valids = ["observer(function Name() {})", "observer(class Name {})"]
+
+const invalidsNotFixed = ["observer(() => {})", "observer(function () {})", "observer(class {})"]
+
+const invalidsFixed = [
+    ["const Cmp = observer(() => {})", "const Cmp = observer(function Cmp()  {})"],
+    ['const Cmp = observer(() => "")', 'const Cmp = observer(function Cmp()  { return "" })'],
+    [
+        "const Cmp = observer(() => expr())",
+        "const Cmp = observer(function Cmp()  { return expr() })"
+    ],
+    [
+        "const Cmp = observer(() => literal)",
+        "const Cmp = observer(function Cmp()  { return literal })"
+    ],
+    ["const Cmp = observer(function () {})", "const Cmp = observer(function Cmp () {})"],
+    ["const Cmp = observer(class {})", "const Cmp = observer(class Cmp {})"]
+]
+
+tester.run("no-anonymous-observer", rule, {
+    valid: valids.map(code => ({ code })),
+    invalid: [
+        ...invalidsNotFixed.map(code => ({
+            code,
+            errors: [{ messageId: "observerComponentMustHaveName" }]
+        })),
+        ...invalidsFixed.map(([code, output]) => ({
+            code,
+            output,
+            errors: [{ messageId: "observerComponentMustHaveName" }]
+        }))
+    ]
+})