eol-tools/src/analyze.js

A set of tools for working with EOL markings in files

/*
Copyright (c) 2018 Bryan Hughes <bryan@nebri.us>

This file is part of EOL Tools.

EOL Tools is free software: you can redistribute it and/or modify
it under the terms of the GNU General Public License as published by
the Free Software Foundation, either version 3 of the License, or
(at your option) any later version.

EOL Tools is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
GNU General Public License for more details.

You should have received a copy of the GNU General Public License
along with EOL Tools.  If not, see <https://www.gnu.org/licenses/>.
*/

const { join } = require('path');
const { readdirSync, readFile, stat } = require('fs');
const { parallel } = require('async');

const types = {
  NONE: 'NONE',
  WINDOWS: 'WINDOWS',
  UNIX: 'UNIX',
  APPLE: 'APPLE',
  MIXED: 'MIXED'
};

function countCharacters(string, character) {
  let count = 0;
  for (let i = 0; i < string.length; i++) {
    if (string[i] === character) {
      count++;
    }
  }
  return count;
}

function analyzeFile(file, cb) {
  stat(file, (err, stats) => {
    if (err) {
      cb(err);
      return;
    } else if (stats.isDirectory()) {
      cb();
      return;
    }
    readFile(file, 'utf8', (err, data) => {
      if (err) {
        cb(err);
        return;
      }
      let numLineFeeds = countCharacters(data, '\n');
      let numCarriageReturns = countCharacters(data, '\r');
      if (numLineFeeds === 0 && numCarriageReturns === 0) {
        cb(undefined, types.NONE);
      } else if (numLineFeeds !== 0 && numCarriageReturns === 0) {
        cb(undefined, types.UNIX);
      } else if (numLineFeeds !== 0 && numCarriageReturns === numLineFeeds) {
        cb(undefined, types.WINDOWS);
      } else if (numLineFeeds !== 0 && numCarriageReturns !== numLineFeeds) {
        cb(undefined, types.MIXED);
      } else if (numLineFeeds === 0 && numCarriageReturns !== 0) {
        cb(undefined, types.APPLE);
      }
    });
  });
}

function findFiles(directory) {
  const contents = readdirSync(directory, { withFileTypes: true });
  const files = [];
  for (const content of contents) {
    const filepath = join(directory, content.name);
    if (content.isDirectory()) {
      files.push(...findFiles(filepath))
    } else if (content.isFile()) {
      files.push(filepath);
    } else if (content.isSymbolicLink()) {
      console.log(`Skipping "${filepath}" because it's a symbolic link`);
    } else {
      console.log(`Skipping ${filepath} because it's not a directory, file, or symbolic link`);
    }
  }
  return files;
}

function analyzeFiles(directories, cb) {
  const fileList = [];
  if (!Array.isArray(directories)) {
    directories = [ directories ];
  }
  for (const directory of directories) {
    fileList.push(...findFiles(directory).filter((file) => file.indexOf('node_modules') === -1));
  }
  const results = {};
  parallel(fileList.map((file) =>
    (done) => analyzeFile(file, (err, type) => {
      if (err) {
        done(err);
      } else {
        results[file] = type;
        done();
      }
    })
  ), (err) => {
    if (err) {
      cb(err);
    } else {
      cb(undefined, results);
    }
  });
}

function run(filePatterns) {
  analyzeFiles(filePatterns, (err, results) => {
    if (err) {
      console.error(err);
      process.exit(-1);
    }
    for (const filename in results) {
      switch (results[filename]) {
        case types.NONE:
          console.log(`No line endings found in ${filename}`);
          break;
        case types.UNIX:
          console.log(`Detected UNIX line endings in ${filename}`);
          break;
        case types.WINDOWS:
          console.log(`Detected Windows line endings in ${filename}`);
          break;
        case types.MIXED:
          console.log(`Detected mixed UNIX and Windows line endings in ${filename}`);
          break;
        case types.APPLE:
          console.log(`Detected old school Apple line endings in ${filename}`);
          break;
      }
    }
  });
};

module.exports = {
  run,
  types,
  analyzeFile,
  analyzeFiles,
}