add pkg-dependency-order rule - fixes #68

config.js

@@ -14,6 +14,7 @@ module.exports = {
 		'pkg-description': 'error',
 		'pkg-name': 'error',
 		'pkg-shorthand-repository': 'error',
+		'pkg-dependency-order': 'error',
 		readme: 'error',
 		'test-script': 'error',
 		'use-travis': 'warn',

docs/rules/pkg-dependency-order.md

@@ -0,0 +1,49 @@
+# Enforces alphabetical order of `dependencies` and `devDependencies` in `package.json`
+
+Enforces an alphabetical order of the `dependencies` and `devDependencies` list in `package.json`.
+
+
+## Fail
+
+```json
+{
+  "name": "foo",
+  "dependencies": {
+    "pify": "*",
+    "clinton": "*"
+  }
+}
+```
+
+```json
+{
+  "name": "foo",
+  "devDependencies": {
+    "xo": "*",
+    "ava": "*"
+  }
+}
+```
+
+
+## Pass
+
+```json
+{
+  "name": "foo",
+  "dependencies": {
+    "clinton": "*",
+    "pify": "*"
+  }
+}
+```
+
+```json
+{
+  "name": "foo",
+  "devDependencies": {
+    "ava": "*",
+    "xo": "*"
+  }
+}
+```

readme.md

@@ -132,6 +132,7 @@ Current working directory when linting local projects.
 - [no-callback](docs/rules/no-callback.md) - Enforces the use of promises instead of callbacks.
 - [no-dup-keywords](docs/rules/no-dup-keywords.md) - Enforce not having duplicate keywords in `package.json`. *(fixable)*
 - [no-git-merge-conflict](docs/rules/no-git-merge-conflict.md) - Prevents having Git merge conflict markers.
+- [pkg-dependency-order](docs/rules/pkg-dependency-order.md) - Enforces alphabetical order of `dependencies` and `devDependencies` in `package.json`. *(fixable)*
 - [pkg-description](docs/rules/pkg-description.md) - Enforces the description to start with a capital letter and not end with a dot. *(fixable)*
 - [pkg-main](docs/rules/pkg-main.md) - Enforces the existance of the main file.
 - [pkg-name](docs/rules/pkg-name.md) - Enforces a valid package name.

rules/pkg-dependency-order.js

@@ -0,0 +1,53 @@
+'use strict';
+const fix = prop => {
+	return pkg => {
+		const ret = {};
+		ret[prop] = Object.create(null);
+
+		const deps = pkg[prop] || {};
+		const orderedDeps = Object.keys(deps).sort();
+
+		for (const dep of orderedDeps) {
+			ret[prop][dep] = deps[dep];
+		}
+
+		return Object.assign(pkg, ret);
+	};
+};
+
+const checkOrder = input => {
+	const keys = Object.keys(input);
+	const orderedKeys = Object.keys(input).sort();
+
+	for (let i = 0; i < keys.length; i++) {
+		if (keys[i] !== orderedKeys[i]) {
+			return [orderedKeys[i], keys[i]];
+		}
+	}
+};
+
+module.exports = ctx => {
+	const file = ctx.fs.resolve('package.json');
+
+	return ctx.fs.readFile('package.json')
+		.then(pkg => {
+			const deps = checkOrder(pkg.dependencies || {});
+			const devDeps = checkOrder(pkg.devDependencies || {});
+
+			if (deps) {
+				ctx.report({
+					message: `Dependency \`${deps[0]}\` should occur before \`${deps[1]}\`.`,
+					fix: fix('dependencies'),
+					file
+				});
+			}
+
+			if (devDeps) {
+				ctx.report({
+					message: `Dev dependency \`${devDeps[0]}\` should occur before \`${devDeps[1]}\`.`,
+					fix: fix('devDependencies'),
+					file
+				});
+			}
+		});
+};

test/fixtures/pkg-dependency-order/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "package",
+  "dependencies": {
+    "clinton": "*",
+    "pify": "*"
+  },
+  "devDependencies": {
+    "ava": "*",
+    "xo": "*"
+  }
+}

test/fixtures/pkg-dependency-order/unordered-dependencies/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "package",
+  "dependencies": {
+    "pify": "*",
+    "clinton": "*"
+  },
+  "devDependencies": {
+    "ava": "*",
+    "xo": "*"
+  }
+}

test/fixtures/pkg-dependency-order/unordered-devdependencies/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "package",
+  "dependencies": {
+    "clinton": "*",
+    "pify": "*"
+  },
+  "devDependencies": {
+    "xo": "*",
+    "ava": "*"
+  }
+}

test/fixtures/pkg-dependency-order/unordered/package.json

@@ -0,0 +1,11 @@
+{
+  "name": "package",
+  "dependencies": {
+    "pify": "*",
+    "clinton": "*"
+  },
+  "devDependencies": {
+    "xo": "*",
+    "ava": "*"
+  }
+}

test/pkg-dependency-order.js

@@ -0,0 +1,111 @@
+import path from 'path';
+import test from 'ava';
+import clintonRuleTester from './fixtures/rule-tester';
+
+const opts = {
+	cwd: 'test/fixtures/pkg-dependency-order',
+	rules: {
+		'pkg-dependency-order': 'error'
+	}
+};
+
+const ruleTester = clintonRuleTester(opts);
+
+test('ordered dependencies and devDependencies', async t => {
+	await ruleTester(t, '.', []);
+});
+
+test('unordered dependencies', async t => {
+	await ruleTester(t, 'unordered-dependencies',
+		[
+			{
+				ruleId: 'pkg-dependency-order',
+				severity: 'error',
+				message: 'Dependency `clinton` should occur before `pify`.',
+				file: path.resolve(opts.cwd, 'unordered-dependencies/package.json')
+			}
+		],
+		[
+			{
+				name: 'package',
+				dependencies: {
+					clinton: '*',
+					pify: '*'
+				},
+				devDependencies: {
+					ava: '*',
+					xo: '*'
+				}
+			}
+		]
+	);
+});
+
+test('unordered devDependencies', async t => {
+	await ruleTester(t, 'unordered-devdependencies',
+		[
+			{
+				ruleId: 'pkg-dependency-order',
+				severity: 'error',
+				message: 'Dev dependency `ava` should occur before `xo`.',
+				file: path.resolve(opts.cwd, 'unordered-devdependencies/package.json')
+			}
+		],
+		[
+			{
+				name: 'package',
+				dependencies: {
+					clinton: '*',
+					pify: '*'
+				},
+				devDependencies: {
+					ava: '*',
+					xo: '*'
+				}
+			}
+		]
+	);
+});
+
+test('unordered dependencies and devDependencies', async t => {
+	await ruleTester(t, 'unordered',
+		[
+			{
+				ruleId: 'pkg-dependency-order',
+				severity: 'error',
+				message: 'Dependency `clinton` should occur before `pify`.',
+				file: path.resolve(opts.cwd, 'unordered/package.json')
+			},
+			{
+				ruleId: 'pkg-dependency-order',
+				severity: 'error',
+				message: 'Dev dependency `ava` should occur before `xo`.',
+				file: path.resolve(opts.cwd, 'unordered/package.json')
+			}
+		],
+		[
+			{
+				name: 'package',
+				dependencies: {
+					clinton: '*',
+					pify: '*'
+				},
+				devDependencies: {
+					xo: '*',
+					ava: '*'
+				}
+			},
+			{
+				name: 'package',
+				dependencies: {
+					pify: '*',
+					clinton: '*'
+				},
+				devDependencies: {
+					ava: '*',
+					xo: '*'
+				}
+			}
+		]
+	);
+});