.prettierignore for gulp-plugin-prettier

gitignore-filter.js

/* eslint-env node*/
'use strict';

const fs = require('fs');
const path = require('path');
const _ = require('lodash');
const ignore = require('ignore');
const gulpFilter = require('gulp-filter');

const filters = new Map();

function getFilter(filterFilePath) {
	if (filters.has(filterFilePath)) {
		return filters.get(filterFilePath);
	}

	const filterBuilder = ignore();
	if (fs.existsSync(filterFilePath)) {
		filterBuilder.add(fs.readFileSync(filterFilePath).toString());
	}

	filters.set(filterFilePath, filterBuilder.createFilter());

	return filters.get(filterFilePath);
}

function getRelativePath(file) {
	return path.relative(process.cwd(), file.path);
}

module.exports = {
	getFilter(filterFilePath = '.gitignore') {
		return getFilter(filterFilePath);
	},

	filterStream(filterFilePath = '.gitignore', options = undefined) {
		const filterFile = _.flow([getRelativePath, getFilter(filterFilePath)]);
		return gulpFilter(filterFile, options);
	},
};

prettier-task.js

const gulp = require('gulp');
const gulpif = require('gulp-if');
const through = require('through2');
const gitignoreFilter = require('./gitignore-filter');
const prettier = require('gulp-plugin-prettier');

function prettier() {
	const prettierFilter = gitignoreFilter.filterStream('.prettierignore', {
		restore: args.fix,
	});
  const prettierOptions = {
    reporter: args.fix ? 'none' : 'error'
  };

  return gulp.src('src/**/*.js')
    .pipe(prettierFilter)
    .pipe(prettier.format(undefined, prettierOptions))
    .pipe(prettierFilter.restore || through.obj())
    .pipe(gulpif(args.fix, gulp.dest('src/')))
}