feat: support package.json linting (#7)

This adds support for using `jsonc-eslint-parser` against your
`package.json` to the ban-dependencies rule.

Author: 43081j

README.md

@@ -39,6 +39,32 @@ export default [
 ];
 ```
 
+### With `package.json`
+
+Some rules (e.g. `ban-dependencies`) can be used against your `package.json`.
+
+You can achieve this by using `jsonc-eslint-parser`.
+
+For example, in your `.eslintrc.json`:
+
+```json
+{
+  "overrides": [
+    {
+      "files": ["package.json"],
+      "parser": "jsonc-eslint-parser",
+      "plugins": ["depend"],
+      "rules": {
+        "depend/ban-dependencies": "error"
+      }
+    }
+  ]
+}
+```
+
+Read more at the
+[`jsonc-eslint-parser` docs](https://github.com/ota-meshi/jsonc-eslint-parser).
+
 ## Rules
 
 - [`depend/ban-dependencies`](./docs/rules/ban-dependencies.md)

package-lock.json

@@ -46,6 +46,7 @@
     "eslint": "^8.56.0",
     "eslint-config-google": "^0.14.0",
     "eslint-plugin-eslint-plugin": "^5.3.0",
+    "jsonc-eslint-parser": "^2.4.0",
     "prettier": "^3.2.5",
     "rimraf": "^5.0.5",
     "typescript": "^5.3.3",

package.json

@@ -10,6 +10,7 @@ const ruleTester = new RuleTester({
 });
 
 const tseslintParser = require.resolve('@typescript-eslint/parser');
+const jsonParser = require.resolve('jsonc-eslint-parser');
 
 ruleTester.run('ban-dependencies', rule, {
   valid: [
@@ -43,6 +44,33 @@ ruleTester.run('ban-dependencies', rule, {
           presets: []
         }
       ]
+    },
+    {
+      code: `{
+        "dependencies": {
+          "unknown-module": "^1.0.0"
+        }
+      }`,
+      filename: 'package.json',
+      parser: jsonParser
+    },
+    {
+      code: `{
+        "dependencies": {
+          "npm-run-all": "^1.0.0"
+        }
+      }`,
+      filename: 'not-a-package.json',
+      parser: jsonParser
+    },
+    {
+      code: `{
+        "not-dependencies": {
+          "some-other-nonsense": 123
+        }
+      }`,
+      filename: 'package.json',
+      parser: jsonParser
     }
   ],
 
@@ -150,6 +178,26 @@ ruleTester.run('ban-dependencies', rule, {
           }
         }
       ]
+    },
+    {
+      code: `{
+        "dependencies": {
+          "npm-run-all": "^1.0.0"
+        }
+      }`,
+      filename: 'package.json',
+      parser: jsonParser,
+      errors: [
+        {
+          line: 3,
+          column: 11,
+          messageId: 'documentedReplacement',
+          data: {
+            name: 'npm-run-all',
+            url: getReplacementsDocUrl('npm-run-all')
+          }
+        }
+      ]
     }
   ]
 });

src/test/rules/ban-dependencies_test.ts

@@ -3,6 +3,7 @@ import {TSESTree} from '@typescript-eslint/typescript-estree';
 import {Replacement} from '../replacements.js';
 import {closestPackageSatisfiesNodeVersion} from './package-json.js';
 import {getMdnUrl, getReplacementsDocUrl} from './rule-meta.js';
+import type {AST as JsonESTree} from 'jsonc-eslint-parser';
 
 export type ImportListenerCallback = (
   context: Rule.RuleContext,
@@ -139,6 +140,46 @@ function replacementListenerCallback(
   }
 }
 
+const dependencyKeys = ['dependencies', 'devDependencies'];
+
+/**
+ * Creates a rule listener for detecting dependencies in a `package.json`
+ * file
+ * @param {Rule.RuleContext} context ESLint context
+ * @param {ImportListenerCallback} callback Listener callback
+ * @return {Rule.RuleListener}
+ */
+export function createPackageJsonListener(
+  context: Rule.RuleContext,
+  callback: ImportListenerCallback
+): Rule.RuleListener {
+  return {
+    'Program > JSONExpressionStatement > JSONObjectExpression > JSONProperty': (
+      astNode: Rule.Node
+    ) => {
+      const node = astNode as unknown as JsonESTree.JSONProperty;
+
+      if (
+        node.key.type === 'JSONLiteral' &&
+        typeof node.key.value === 'string' &&
+        dependencyKeys.includes(node.key.value) &&
+        node.value.type === 'JSONObjectExpression'
+      ) {
+        for (const prop of node.value.properties) {
+          if (
+            prop.key.type === 'JSONLiteral' &&
+            typeof prop.key.value === 'string'
+          ) {
+            callback(context, prop as unknown as Rule.Node, prop.key.value);
+          }
+        }
+      }
+    }
+  };
+}
+
+const packageJsonLikePath = /(^|[/\\])package.json$/;
+
 /**
  * Creates a rule listener which finds replacements in imports/requires
  * @param {Rule.RuleContext} context ESLint context
@@ -149,6 +190,12 @@ export function createReplacementListener(
   context: Rule.RuleContext,
   replacements: Replacement[]
 ): Rule.RuleListener {
+  if (packageJsonLikePath.test(context.filename)) {
+    return createPackageJsonListener(context, (context, node, name) =>
+      replacementListenerCallback(context, replacements, node, name)
+    );
+  }
+
   return createImportListener(context, (context, node, source) =>
     replacementListenerCallback(context, replacements, node, source)
   );