test: add test cases (#233)

Author: ota-meshi

tests/fixtures/integrations/type-info-tests/no-unnecessary-condition01-input.svelte

@@ -0,0 +1,10 @@
+<script lang="ts">
+    export let foo: null | boolean = null
+
+    const a = foo == null
+    $: b = foo == null
+    $: {
+        let bar: null | boolean = null
+        c = bar == null
+    }
+</script>

tests/fixtures/integrations/type-info-tests/no-unnecessary-condition01-output.json

@@ -0,0 +1,16 @@
+[
+  {
+    "ruleId": "@typescript-eslint/no-unnecessary-condition",
+    "code": "foo == null",
+    "line": 4,
+    "column": 15,
+    "message": "Unnecessary conditional, both sides of the expression are literal values."
+  },
+  {
+    "ruleId": "@typescript-eslint/no-unnecessary-condition",
+    "code": "bar == null",
+    "line": 8,
+    "column": 13,
+    "message": "Unnecessary conditional, both sides of the expression are literal values."
+  }
+]

tests/fixtures/integrations/type-info-tests/no-unnecessary-condition01-setup.ts

@@ -0,0 +1,24 @@
+/* eslint eslint-comments/require-description: 0, @typescript-eslint/explicit-module-boundary-types: 0 */
+import type { Linter } from "eslint";
+import { BASIC_PARSER_OPTIONS } from "../../../src/parser/test-utils";
+import { rules } from "@typescript-eslint/eslint-plugin";
+export function setupLinter(linter: Linter) {
+  linter.defineRule(
+    "@typescript-eslint/no-unnecessary-condition",
+    rules["no-unnecessary-condition"] as never
+  );
+}
+
+export function getConfig() {
+  return {
+    parser: "svelte-eslint-parser",
+    parserOptions: BASIC_PARSER_OPTIONS,
+    rules: {
+      "@typescript-eslint/no-unnecessary-condition": "error",
+    },
+    env: {
+      browser: true,
+      es2021: true,
+    },
+  };
+}

tests/fixtures/integrations/type-info-tests/no-unnecessary-condition02-input.svelte

@@ -0,0 +1,11 @@
+<script lang="ts">
+    export let foo: null | boolean = null
+    export let bar: string = "foo"
+
+    const a = foo ?? bar
+    $: b = foo ?? bar
+    $: {
+        let baz: null | boolean = null
+        c = baz ?? bar
+    }
+</script>

tests/fixtures/integrations/type-info-tests/no-unnecessary-condition02-output.json

@@ -0,0 +1,16 @@
+[
+  {
+    "ruleId": "@typescript-eslint/no-unnecessary-condition",
+    "code": "foo",
+    "line": 5,
+    "column": 15,
+    "message": "Unnecessary conditional, left-hand side of `??` operator is always `null` or `undefined`."
+  },
+  {
+    "ruleId": "@typescript-eslint/no-unnecessary-condition",
+    "code": "baz",
+    "line": 9,
+    "column": 13,
+    "message": "Unnecessary conditional, left-hand side of `??` operator is always `null` or `undefined`."
+  }
+]

tests/fixtures/integrations/type-info-tests/no-unnecessary-condition02-setup.ts

@@ -0,0 +1,2 @@
+/* eslint eslint-comments/require-description: 0, @typescript-eslint/explicit-module-boundary-types: 0 */
+export * from "./no-unnecessary-condition01-setup";

tests/fixtures/integrations/type-info-tests/no-unnecessary-condition03-input.svelte

@@ -0,0 +1,10 @@
+<script lang="ts">
+    export let foo: null | string = "abc"
+
+    const a = foo?.length
+    $: b = foo?.length
+    $: {
+        let bar: null | string = "abc"
+        c = bar?.length
+    }
+</script>

tests/fixtures/integrations/type-info-tests/no-unnecessary-condition03-output.json

@@ -0,0 +1,16 @@
+[
+  {
+    "ruleId": "@typescript-eslint/no-unnecessary-condition",
+    "code": "?.",
+    "line": 4,
+    "column": 18,
+    "message": "Unnecessary optional chain on a non-nullish value."
+  },
+  {
+    "ruleId": "@typescript-eslint/no-unnecessary-condition",
+    "code": "?.",
+    "line": 8,
+    "column": 16,
+    "message": "Unnecessary optional chain on a non-nullish value."
+  }
+]

tests/fixtures/integrations/type-info-tests/no-unnecessary-condition03-setup.ts

@@ -0,0 +1,2 @@
+/* eslint eslint-comments/require-description: 0, @typescript-eslint/explicit-module-boundary-types: 0 */
+export * from "./no-unnecessary-condition01-setup";