Add jsonc/no-number-props rule (#10)

* Add `jsonc/no-number-props` rule

* add testcase

Author: ota-meshi

README.md

@@ -136,6 +136,7 @@ The rules with the following star :star: are included in the config.
 | Rule ID | Description | Fixable | JSON | JSONC | JSON5 |
 |:--------|:------------|:-------:|:----:|:-----:|:-----:|
 | [jsonc/no-comments](https://ota-meshi.github.io/eslint-plugin-jsonc/rules/no-comments.html) | disallow comments |  | :star: |  |  |
+| [jsonc/no-number-props](https://ota-meshi.github.io/eslint-plugin-jsonc/rules/no-number-props.html) | disallow number property keys | :wrench: | :star: | :star: | :star: |
 | [jsonc/no-template-literals](https://ota-meshi.github.io/eslint-plugin-jsonc/rules/no-template-literals.html) | disallow template literals | :wrench: | :star: | :star: | :star: |
 | [jsonc/no-undefined-value](https://ota-meshi.github.io/eslint-plugin-jsonc/rules/no-undefined-value.html) | disallow `undefined` |  | :star: | :star: | :star: |
 | [jsonc/valid-json-number](https://ota-meshi.github.io/eslint-plugin-jsonc/rules/valid-json-number.html) | disallow invalid number for JSON | :wrench: | :star: | :star: |  |

docs/rules/README.md

@@ -14,6 +14,7 @@ The rules with the following star :star: are included in the `plugin:jsonc/recom
 | Rule ID | Description | Fixable | JSON | JSONC | JSON5 |
 |:--------|:------------|:-------:|:----:|:-----:|:-----:|
 | [jsonc/no-comments](./no-comments.md) | disallow comments |  | :star: |  |  |
+| [jsonc/no-number-props](./no-number-props.md) | disallow number property keys | :wrench: | :star: | :star: | :star: |
 | [jsonc/no-template-literals](./no-template-literals.md) | disallow template literals | :wrench: | :star: | :star: | :star: |
 | [jsonc/no-undefined-value](./no-undefined-value.md) | disallow `undefined` |  | :star: | :star: | :star: |
 | [jsonc/valid-json-number](./valid-json-number.md) | disallow invalid number for JSON | :wrench: | :star: | :star: |  |

docs/rules/no-number-props.md

@@ -0,0 +1,46 @@
+---
+pageClass: "rule-details"
+sidebarDepth: 0
+title: "jsonc/no-number-props"
+description: "disallow number property keys"
+---
+# jsonc/no-number-props
+
+> disallow number property keys
+
+- :gear: This rule is included in all of `"plugin:jsonc/recommended-with-json"`, `"plugin:jsonc/recommended-with-json5"` and `"plugin:jsonc/recommended-with-jsonc"`.
+- :wrench: The `--fix` option on the [command line](https://eslint.org/docs/user-guide/command-line-interface#fixing-problems) can automatically fix some of the problems reported by this rule.
+
+## :book: Rule Details
+
+This rule reports the use of number property keys.
+
+JSON, JSONC and JSON5 do not allow number property keys.
+
+<eslint-code-block fix>
+
+```json5
+/* eslint jsonc/no-number-props: 'error' */
+{
+    /* ✓ GOOD */
+    "GOOD": {
+      "42": "foo"
+    },
+
+    /* ✗ BAD */
+    "BAD": {
+      42: "foo"
+    }
+}
+```
+
+</eslint-code-block>
+
+## :wrench: Options
+
+Nothing.
+
+## Implementation
+
+- [Rule source](https://github.com/ota-meshi/eslint-plugin-jsonc/blob/master/lib/rules/no-number-props.ts)
+- [Test source](https://github.com/ota-meshi/eslint-plugin-jsonc/blob/master/tests/lib/rules/no-number-props.js)

lib/configs/recommended-with-json.ts

@@ -10,6 +10,7 @@ export = {
         "jsonc/no-comments": "error",
         "jsonc/no-dupe-keys": "error",
         "jsonc/no-multi-str": "error",
+        "jsonc/no-number-props": "error",
         "jsonc/no-sparse-arrays": "error",
         "jsonc/no-template-literals": "error",
         "jsonc/no-undefined-value": "error",

lib/configs/recommended-with-json5.ts

@@ -7,6 +7,7 @@ export = {
     rules: {
         // eslint-plugin-jsonc rules
         "jsonc/no-dupe-keys": "error",
+        "jsonc/no-number-props": "error",
         "jsonc/no-sparse-arrays": "error",
         "jsonc/no-template-literals": "error",
         "jsonc/no-undefined-value": "error",

lib/configs/recommended-with-jsonc.ts

@@ -8,6 +8,7 @@ export = {
         // eslint-plugin-jsonc rules
         "jsonc/no-dupe-keys": "error",
         "jsonc/no-multi-str": "error",
+        "jsonc/no-number-props": "error",
         "jsonc/no-sparse-arrays": "error",
         "jsonc/no-template-literals": "error",
         "jsonc/no-undefined-value": "error",

lib/rules/no-number-props.ts

@@ -0,0 +1,40 @@
+import type { JSONProperty } from "../parser/ast"
+import { createRule } from "../utils"
+
+export default createRule("no-number-props", {
+    meta: {
+        docs: {
+            description: "disallow number property keys",
+            recommended: ["json", "jsonc", "json5"],
+            extensionRule: false,
+        },
+        fixable: "code",
+        schema: [],
+        messages: {
+            unexpected: "The number property keys are not allowed.",
+        },
+        type: "problem",
+    },
+    create(context) {
+        return {
+            JSONProperty(node: JSONProperty) {
+                if (node.key.type !== "JSONLiteral") {
+                    return
+                }
+                if (typeof node.key.value === "number") {
+                    const raw = node.key.raw
+                    context.report({
+                        loc: node.key.loc,
+                        messageId: "unexpected",
+                        fix(fixer) {
+                            return fixer.replaceTextRange(
+                                node.key.range,
+                                `"${raw}"`,
+                            )
+                        },
+                    })
+                }
+            },
+        }
+    },
+})

lib/utils/rules.ts

@@ -9,6 +9,7 @@ import keySpacing from "../rules/key-spacing"
 import noComments from "../rules/no-comments"
 import noDupeKeys from "../rules/no-dupe-keys"
 import noMultiStr from "../rules/no-multi-str"
+import noNumberProps from "../rules/no-number-props"
 import noOctalEscape from "../rules/no-octal-escape"
 import noSparseArrays from "../rules/no-sparse-arrays"
 import noTemplateLiterals from "../rules/no-template-literals"
@@ -34,6 +35,7 @@ export const rules = [
     noComments,
     noDupeKeys,
     noMultiStr,
+    noNumberProps,
     noOctalEscape,
     noSparseArrays,
     noTemplateLiterals,

tests/lib/rules/no-number-props.ts

@@ -0,0 +1,17 @@
+import { RuleTester } from "eslint"
+import rule from "../../../lib/rules/no-number-props"
+
+const tester = new RuleTester({
+    parser: require.resolve("../../../lib/parser/json-eslint-parser"),
+})
+
+tester.run("no-number-props", rule as any, {
+    valid: ['{"key": 123}', "{key: 123}", "123", "[123]"],
+    invalid: [
+        {
+            code: "{123: 123}",
+            output: '{"123": 123}',
+            errors: ["The number property keys are not allowed."],
+        },
+    ],
+})