Add projectSuffix option (#52)

Fixes #35


Co-authored-by: Sindre Sorhus <sindresorhus@gmail.com>

index.js

@@ -33,11 +33,12 @@ class Conf {
 
 		options = Object.assign({
 			configName: 'config',
-			fileExtension: 'json'
+			fileExtension: 'json',
+			projectSuffix: 'nodejs'
 		}, options);
 
 		if (!options.cwd) {
-			options.cwd = envPaths(options.projectName).config;
+			options.cwd = envPaths(options.projectName, {suffix: options.projectSuffix}).config;
 		}
 
 		this.events = new EventEmitter();

readme.md

@@ -107,6 +107,19 @@ Extension of the config file.
 
 You would usually not need this, but could be useful if you want to interact with a file with a custom file extension that can be associated with your app. These might be simple save/export/preference files that are intended to be shareable or saved outside of the app.
 
+#### projectSuffix
+
+Type: `string`<br>
+Default: `nodejs`
+
+**You most likely don't need this. Please don't use it unless you really have to.**
+
+Suffix appended to `projectName` during config file creation to avoid name conflicts with native apps.
+
+You can pass an empty string to remove the suffix.
+
+For example, on macOS, the config file will be stored in the `~/Library/Preferences/foo-nodejs` directory, where `foo` is the `projectName`.
+
 ### Instance
 
 You can use [dot-notation](https://github.com/sindresorhus/dot-prop) in a `key` to access nested properties.

test.js

@@ -126,6 +126,30 @@ test('`configName` option', t => {
 	t.is(path.basename(conf.path, '.json'), configName);
 });
 
+test('no `suffix` option', t => {
+	const conf = new Conf();
+	t.true(conf.path.includes('-nodejs'));
+});
+
+test('with `suffix` option set to empty string', t => {
+	const projectSuffix = '';
+	const projectName = 'conf-temp1-project';
+	const conf = new Conf({projectSuffix, projectName});
+	const configPathSegments = conf.path.split(path.sep);
+	const configRootIndex = configPathSegments.findIndex(segment => segment === projectName);
+	t.true(configRootIndex >= 0 && configRootIndex < configPathSegments.length);
+});
+
+test('with `projectSuffix` option set to non-empty string', t => {
+	const projectSuffix = 'new-projectSuffix';
+	const projectName = 'conf-temp2-project';
+	const conf = new Conf({projectSuffix, projectName});
+	const configPathSegments = conf.path.split(path.sep);
+	const expectedRootName = `${projectName}-${projectSuffix}`;
+	const configRootIndex = configPathSegments.findIndex(segment => segment === expectedRootName);
+	t.true(configRootIndex >= 0 && configRootIndex < configPathSegments.length);
+});
+
 test('`fileExtension` option', t => {
 	const fileExtension = 'alt-ext';
 	const conf = new Conf({