Merge branch 'main' into eslint-fix-utils

README.md

@@ -122,6 +122,7 @@ The default settings don't conflict, and Prettier plugins can quickly fix up ord
 
 | Name                                                                   | Description                                                                                       | 💼 | 🔧 | 💡 | ❌  |
 | :--------------------------------------------------------------------- | :------------------------------------------------------------------------------------------------ | :- | :- | :- | :- |
+| [no-empty-fields](docs/rules/no-empty-fields.md)                       | Reports on unnecessary empty arrays and objects.                                                  | ✅  |    | 💡 |    |
 | [no-redundant-files](docs/rules/no-redundant-files.md)                 | Prevents adding unnecessary / redundant files.                                                    |    |    | 💡 |    |
 | [order-properties](docs/rules/order-properties.md)                     | Package properties must be declared in standard order                                             | ✅  | 🔧 |    |    |
 | [repository-shorthand](docs/rules/repository-shorthand.md)             | Enforce either object or shorthand declaration for repository.                                    | ✅  | 🔧 |    |    |

docs/rules/no-empty-fields.md

@@ -0,0 +1,37 @@
+# no-empty-fields
+
+💼 This rule is enabled in the ✅ `recommended` config.
+
+💡 This rule is manually fixable by [editor suggestions](https://eslint.org/docs/latest/use/core-concepts#rule-suggestions).
+
+<!-- end auto-generated rule header -->
+
+This rule flags all empty arrays and objects in a `package.json`,
+as such empty expressions do nothing, and are often the result of a mistake.
+It will report both named properties that are empty, as well as nested arrays and objects
+that are empty.
+
+Example of **incorrect** code for this rule:
+
+```json
+{
+	"main": "lib/index.js",
+	"scripts": {},
+	"files": [],
+	"simple-git-hooks": {
+		"pre-commit": "pnpm exec nano-staged --allow-empty",
+		"preserveUnused": []
+	}
+}
+```
+
+Example of **correct** code for this rule:
+
+```json
+{
+	"main": "lib/index.js",
+	"simple-git-hooks": {
+		"pre-commit": "pnpm exec nano-staged --allow-empty"
+	}
+}
+```

src/plugin.ts

@@ -2,6 +2,7 @@ import { createRequire } from "node:module";
 
 import type { PackageJsonRuleModule } from "./createRule.js";
 
+import { rule as noEmptyFields } from "./rules/no-empty-fields.js";
 import { rule as noRedundantFiles } from "./rules/no-redundant-files.js";
 import { rule as orderProperties } from "./rules/order-properties.js";
 import { rule as preferRepositoryShorthand } from "./rules/repository-shorthand.js";
@@ -21,6 +22,7 @@ const { name, version } = require("../package.json") as {
 };
 
 const rules: Record<string, PackageJsonRuleModule> = {
+	"no-empty-fields": noEmptyFields,
 	"no-redundant-files": noRedundantFiles,
 	"order-properties": orderProperties,
 	"repository-shorthand": preferRepositoryShorthand,

src/rules/no-empty-fields.ts

@@ -0,0 +1,122 @@
+import type { AST as JsonAST } from "jsonc-eslint-parser";
+
+import * as ESTree from "estree";
+
+import { createRule, PackageJsonRuleContext } from "../createRule";
+
+const getDataAndMessageId = (
+	node:
+		| JsonAST.JSONArrayExpression
+		| JsonAST.JSONObjectExpression
+		| JsonAST.JSONProperty,
+): {
+	data: Record<string, string>;
+	messageId: "emptyExpression" | "emptyFields";
+} => {
+	switch (node.type) {
+		case "JSONArrayExpression":
+			return {
+				data: {
+					expressionType: "array",
+				},
+				messageId: "emptyExpression",
+			};
+		case "JSONObjectExpression":
+			return {
+				data: {
+					expressionType: "object",
+				},
+				messageId: "emptyExpression",
+			};
+		case "JSONProperty":
+			return {
+				data: {
+					field: (node.key as JsonAST.JSONStringLiteral).value,
+				},
+				messageId: "emptyFields",
+			};
+	}
+};
+
+const report = (
+	context: PackageJsonRuleContext,
+	node:
+		| JsonAST.JSONArrayExpression
+		| JsonAST.JSONObjectExpression
+		| JsonAST.JSONProperty,
+) => {
+	const { data, messageId } = getDataAndMessageId(node);
+	context.report({
+		data,
+		messageId,
+		node: node as unknown as ESTree.Node,
+		suggest: [
+			{
+				*fix(fixer) {
+					yield fixer.remove(node as unknown as ESTree.Node);
+
+					const tokenFromCurrentLine =
+						context.sourceCode.getTokenAfter(
+							node as unknown as ESTree.Node,
+						);
+					const tokenFromPreviousLine =
+						context.sourceCode.getTokenBefore(
+							node as unknown as ESTree.Node,
+						);
+
+					if (
+						tokenFromPreviousLine?.value === "," &&
+						tokenFromCurrentLine?.value !== ","
+					) {
+						yield fixer.remove(tokenFromPreviousLine);
+					}
+
+					if (tokenFromCurrentLine?.value === ",") {
+						yield fixer.remove(tokenFromCurrentLine);
+					}
+				},
+				messageId: "remove",
+			},
+		],
+	});
+};
+
+const getNode = (
+	node: JsonAST.JSONArrayExpression | JsonAST.JSONObjectExpression,
+) => {
+	return node.parent.type === "JSONProperty" ? node.parent : node;
+};
+
+export const rule = createRule({
+	create(context) {
+		return {
+			JSONArrayExpression(node: JsonAST.JSONArrayExpression) {
+				if (!node.elements.length) {
+					report(context, getNode(node));
+				}
+			},
+			JSONObjectExpression(node: JsonAST.JSONObjectExpression) {
+				if (!node.properties.length) {
+					report(context, getNode(node));
+				}
+			},
+		};
+	},
+	meta: {
+		docs: {
+			category: "Best Practices",
+			description: "Reports on unnecessary empty arrays and objects.",
+			recommended: true,
+		},
+		hasSuggestions: true,
+		messages: {
+			emptyExpression:
+				"This {{expressionType}} does nothing and can be removed.",
+			emptyFields:
+				"The field '{{field}}' does nothing and can be removed.",
+			remove: "Remove this empty field.",
+		},
+		schema: [],
+		type: "suggestion",
+	},
+});