Initial implementation, tests, readme

.eslintrc

@@ -0,0 +1,10 @@
+{
+	"root": true,
+
+	"extends": "@ljharb/eslint-config/node/20",
+
+	"rules": {
+		"no-console": "off",
+		"no-process-exit": "off",
+	},
+}

.github/FUNDING.yml

@@ -0,0 +1,12 @@
+# These are supported funding model platforms
+
+github: [ljharb]
+patreon: # Replace with a single Patreon username
+open_collective: # Replace with a single Open Collective username
+ko_fi: # Replace with a single Ko-fi username
+tidelift: npm/nvmrc
+community_bridge: # Replace with a single Community Bridge project-name e.g., cloud-foundry
+liberapay: # Replace with a single Liberapay username
+issuehunt: # Replace with a single IssueHunt username
+otechie: # Replace with a single Otechie username
+custom: # Replace with a single custom sponsorship URL

.github/workflows/node-pretest.yml

@@ -0,0 +1,10 @@
+name: 'Tests: pretest/posttest'
+
+on: [pull_request, push]
+
+permissions:
+  contents: read
+
+jobs:
+  tests:
+    uses: ljharb/actions/.github/workflows/pretest.yml@main

.github/workflows/node.yml

@@ -0,0 +1,14 @@
+name: 'Tests: node.js'
+
+on: [pull_request, push]
+
+permissions:
+  contents: read
+
+jobs:
+  tests:
+    uses: ljharb/actions/.github/workflows/node.yml@main
+    with:
+      range: '>= 22'
+      type: minors
+      command: npm run tests-only

.github/workflows/rebase.yml

@@ -0,0 +1,22 @@
+name: Automatic Rebase
+
+on: [pull_request_target]
+
+permissions:
+  contents: read
+
+jobs:
+  _:
+    permissions:
+      contents: write  # for ljharb/rebase to push code to rebase
+      pull-requests: read  # for ljharb/rebase to get info about PR
+
+    name: "Automatic Rebase"
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: actions/checkout@v3
+      - uses: ljharb/rebase@master
+        env:
+          GITHUB_TOKEN: ${{ secrets.GITHUB_TOKEN }}

.github/workflows/require-allow-edits.yml

@@ -0,0 +1,18 @@
+name: Require “Allow Edits”
+
+on: [pull_request_target]
+
+permissions:
+  contents: read
+
+jobs:
+  _:
+    permissions:
+      pull-requests: read  # for ljharb/require-allow-edits to check 'allow edits' on PR
+
+    name: "Require “Allow Edits”"
+
+    runs-on: ubuntu-latest
+
+    steps:
+      - uses: ljharb/require-allow-edits@main

.gitignore

@@ -133,3 +133,5 @@ dist
 npm-shrinkwrap.json
 package-lock.json
 yarn.lock
+
+.npmignore

.nycrc

@@ -0,0 +1,10 @@
+{
+	"exclude": [
+		"test/**"
+	],
+	"reporter": [
+		"html",
+		"lcov",
+		"text"
+	]
+}

CHANGELOG.md

@@ -0,0 +1,6 @@
+# Changelog
+
+All notable changes to this project will be documented in this file.
+
+The format is based on [Keep a Changelog](https://keepachangelog.com/en/1.0.0/)
+and this project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).

README.md

@@ -1,2 +1,53 @@
-# nvmrc
+# nvmrc <sup>[![Version Badge][npm-version-svg]][package-url]</sup>
+
+[![github actions][actions-image]][actions-url]
+[![coverage][codecov-image]][codecov-url]
+[![License][license-image]][license-url]
+[![Downloads][downloads-image]][downloads-url]
+
+[![npm badge][npm-badge-png]][package-url]
+
 command-line tool to validate a `.nvmrc` file
+
+## Example
+
+Run:
+```sh
+$ nvmrc
+```
+
+When valid, the parsed JSON will be logged.
+
+When invalid:
+```sh
+invalid .nvmrc!
+all non-commented content (anything after # is a comment) must be either:
+  - a single bare nvm-recognized version-ish
+  - or, multiple distinct key-value pairs, each key/value separated by a single equals sign (=)
+
+non-commented content parsed:
+…
+```
+
+## Tests
+Simply clone the repo, `npm install`, and run `npm test`
+
+## Security
+
+Please email [@ljharb](https://github.com/ljharb) or see https://tidelift.com/security if you have a potential security vulnerability to report.
+
+[package-url]: https://npmjs.org/package/nvmrc
+[npm-version-svg]: https://versionbadg.es/nvm-sh/nvmrc.svg
+[deps-svg]: https://david-dm.org/nvm-sh/nvmrc.svg
+[deps-url]: https://david-dm.org/nvm-sh/nvmrc
+[dev-deps-svg]: https://david-dm.org/nvm-sh/nvmrc/dev-status.svg
+[dev-deps-url]: https://david-dm.org/nvm-sh/nvmrc#info=devDependencies
+[npm-badge-png]: https://nodei.co/npm/nvmrc.png?downloads=true&stars=true
+[license-image]: https://img.shields.io/npm/l/nvmrc.svg
+[license-url]: LICENSE
+[downloads-image]: https://img.shields.io/npm/dm/nvmrc.svg
+[downloads-url]: https://npm-stat.com/charts.html?package=nvmrc
+[codecov-image]: https://codecov.io/gh/nvm-sh/nvmrc/branch/main/graphs/badge.svg
+[codecov-url]: https://app.codecov.io/gh/nvm-sh/nvmrc/
+[actions-image]: https://img.shields.io/endpoint?url=https://github-actions-badge-u3jn4tfpocch.runkit.sh/nvm-sh/nvmrc
+[actions-url]: https://github.com/nvm-sh/nvmrc/actions

nvmrc.mjs

@@ -0,0 +1,42 @@
+#! /usr/bin/env node
+
+import { readFile } from 'fs/promises';
+import { join } from 'path';
+
+const contentsP = readFile(join(process.cwd(), '.nvmrc'));
+
+const contentsStr = `${await contentsP}`;
+
+const rawOptions = contentsStr
+	.split('\n')
+	.map((x) => x.replace(/#.*$/, '').trim())
+	.filter(Boolean);
+
+const optionsEntries = rawOptions.map((x) => ((/[=]/).test(x)
+	? x.split('=').map((y) => y.trim())
+	: ['node', x]
+));
+
+const map = new Map(optionsEntries);
+
+if (map.size !== optionsEntries.length || !map.has('node') || rawOptions.filter((x) => !x.includes('=')).length !== 1) {
+	console.error(`
+invalid .nvmrc!
+all non-commented content (anything after # is a comment) must be either:
+  - a single bare nvm-recognized version-ish
+  - or, multiple distinct key-value pairs, each key/value separated by a single equals sign (=)
+
+additionally, a single bare nvm-recognized version-ish must be present (after stripping comments).
+`);
+
+	console.warn(`
+non-commented content parsed:
+${rawOptions.join('\n')}
+`);
+
+	process.exit(1);
+}
+
+const options = Object.fromEntries(optionsEntries);
+
+console.log(JSON.stringify(options, null, '\t').replace(/\n\s*/g, ' '));

package.json

@@ -2,12 +2,22 @@
 	"name": "nvmrc",
 	"version": "0.0.0",
 	"description": "command-line tool to validate a `.nvmrc` file",
+	"bin": "./nvmrc.mjs",
 	"main": false,
 	"exports": {
 		"./package.json": "./package.json"
 	},
 	"scripts": {
-		"test": "echo \"Error: no test specified\" && exit 1"
+		"prepack": "npmignore --auto --commentLines=autogenerated",
+		"prepublish": "not-in-publish || npm run prepublishOnly",
+		"prepublishOnly": "safe-publish-latest",
+		"lint": "eslint --ext=js,mjs .",
+		"pretest": "npm run lint",
+		"tests-only": "NODE_OPTIONS='--no-warnings' c8 tape 'test/*.mjs'",
+		"test": "npm run tests-only",
+		"posttest": "aud --production",
+		"version": "auto-changelog && git add CHANGELOG.md",
+		"postversion": "auto-changelog && git add CHANGELOG.md && git commit --no-edit --amend && git tag -f \"v$(node -e \"console.log(require('./package.json').version)\")\""
 	},
 	"repository": {
 		"type": "git",
@@ -23,5 +33,39 @@
 	"bugs": {
 		"url": "https://github.com/nvm-sh/nvmrc/issues"
 	},
-	"homepage": "https://github.com/nvm-sh/nvmrc#readme"
+	"homepage": "https://github.com/nvm-sh/nvmrc#readme",
+	"engines": {
+		"node": "^20 || >= 22"
+	},
+	"devDependencies": {
+		"@ljharb/eslint-config": "^21.1.1",
+		"aud": "^2.0.4",
+		"auto-changelog": "^2.4.0",
+		"c8": "^9.1.0",
+		"eslint": "^8.8.0",
+		"in-publish": "^2.0.1",
+		"npmignore": "^0.3.1",
+		"safe-publish-latest": "^2.0.0",
+		"strip-color": "^0.1.0",
+		"tape": "^5.7.5"
+	},
+	"testling": {
+		"files": "test/*.js"
+	},
+	"auto-changelog": {
+		"output": "CHANGELOG.md",
+		"template": "keepachangelog",
+		"unreleased": false,
+		"commitLimit": false,
+		"backfillLimit": false,
+		"hideCredit": true
+	},
+	"publishConfig": {
+		"ignore": [
+			".github/workflows",
+			"test",
+			".nycrc",
+			".eslintrc"
+		]
+	}
 }

test/fixtures/basic-comments/.nvmrc

@@ -0,0 +1,3 @@
+v20
+
+# this is a comment

test/fixtures/basic-invalid/.nvmrc

@@ -0,0 +1,2 @@
+foo
+bar

test/fixtures/basic-with-comment/.nvmrc

@@ -0,0 +1 @@
+21.2 # this is an inline comment

test/fixtures/basic-with-npm/.nvmrc

@@ -0,0 +1,2 @@
+node
+npm=10

test/fixtures/basic/.nvmrc

@@ -0,0 +1 @@
+node

test/fixtures/duplicate-pairs/.nvmrc

@@ -0,0 +1,4 @@
+node
+
+npm=3
+npm=4

test/fixtures/invalid/.nvmrc

@@ -0,0 +1 @@
+a=b

test/fixtures/only-comments/.nvmrc

@@ -0,0 +1,2 @@
+# this is a comment
+# nothing here but us comments!

test/fixtures/pre-normalized/.nvmrc

@@ -0,0 +1,2 @@
+node=foo
+npm=bar

test/index.mjs

@@ -0,0 +1,73 @@
+import { spawnSync } from 'child_process';
+import { join } from 'path';
+import { readdirSync } from 'fs';
+
+import test from 'tape';
+
+import stripColors from 'strip-color';
+
+const fixtureDir = join(import.meta.dirname, 'fixtures');
+
+const fixtures = readdirSync(fixtureDir);
+
+test('nvmrc', async (t) => {
+	const valid = [
+		'basic',
+		'basic-comments',
+		'basic-with-comment',
+		'basic-with-npm',
+	];
+
+	const invalid = [
+		'basic-invalid',
+		'invalid',
+		'only-comments',
+		'pre-normalized',
+		'duplicate-pairs',
+	];
+
+	t.deepEqual(fixtures.sort(), valid.concat(invalid).sort(), 'all fixtures are accounted for');
+
+	const bin = join(import.meta.dirname, '../nvmrc.mjs');
+
+	for (const fixture of valid) {
+		t.test(`fixture ${fixture}`, (st) => {
+			const cwd = join(fixtureDir, fixture);
+
+			const { stdout, status } = spawnSync(`${bin}`, { cwd });
+
+			st.equal(status, 0, 'yields a zero exit code');
+
+			const stripped = stripColors(`${stdout}`);
+
+			st.doesNotThrow(() => JSON.parse(stripped), `fixture ${fixture} is valid, yields ${stripped.replace(/\n\s*/g, ' ')}`);
+
+			st.end();
+		});
+	}
+
+	for (const fixture of invalid) {
+		t.test(`fixture ${fixture}`, (st) => {
+			const cwd = join(fixtureDir, fixture);
+
+			const { status, stderr } = spawnSync(`${bin}`, { cwd });
+
+			st.notEqual(status, 0, `fixture ${fixture} did not produce a zero exit code`);
+
+			const stripped = stripColors(`${stderr}`);
+
+			const lines = stripped.split('\n').map((x) => x.trim()).filter(Boolean);
+
+			st.deepEqual(lines.slice(0, 6), [
+				'invalid .nvmrc!',
+				'all non-commented content (anything after # is a comment) must be either:',
+				'- a single bare nvm-recognized version-ish',
+				'- or, multiple distinct key-value pairs, each key/value separated by a single equals sign (=)',
+				'additionally, a single bare nvm-recognized version-ish must be present (after stripping comments).',
+				'non-commented content parsed:',
+			]);
+
+			st.end();
+		});
+	}
+});