add node modules to repo

node_modules/sumchecker/index.js

@@ -0,0 +1,176 @@
+/*
+Copyright 2016 Mark Lee
+
+Licensed under the Apache License, Version 2.0 (the "License");
+you may not use this file except in compliance with the License.
+You may obtain a copy of the License at
+
+    http://www.apache.org/licenses/LICENSE-2.0
+
+Unless required by applicable law or agreed to in writing, software
+distributed under the License is distributed on an "AS IS" BASIS,
+WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+See the License for the specific language governing permissions and
+limitations under the License.
+*/
+
+'use strict'
+
+const debug = require('debug')('sumchecker')
+const crypto = require('crypto')
+const fs = require('fs')
+const path = require('path')
+const Promise = global.Promise || require('es6-promise').Promise
+
+const CHECKSUM_LINE = /^([\da-fA-F]+) ([ *])(.+)$/
+
+class ErrorWithFilename extends Error {
+  constructor (filename) {
+    super()
+    this.filename = filename
+  }
+}
+
+class ChecksumMismatchError extends ErrorWithFilename {
+  constructor (filename) {
+    super(filename)
+    this.message = `Generated checksum for "${filename}" did not match expected checksum.`
+  }
+}
+
+class ChecksumParseError extends Error {
+  constructor (lineNumber, line) {
+    super()
+    this.lineNumber = lineNumber
+    this.line = line
+    this.message = `Could not parse checksum file at line ${lineNumber}: ${line}`
+  }
+}
+
+class NoChecksumFoundError extends ErrorWithFilename {
+  constructor (filename) {
+    super(filename)
+    this.message = `No checksum found in checksum file for "${filename}".`
+  }
+}
+
+class ChecksumValidator {
+  constructor (algorithm, checksumFilename, options) {
+    this.algorithm = algorithm
+    this.checksumFilename = checksumFilename
+    this.checksums = null
+
+    if (options && options.defaultTextEncoding) {
+      this.defaultTextEncoding = options.defaultTextEncoding
+    } else {
+      this.defaultTextEncoding = 'utf8'
+    }
+  }
+
+  encoding (binary) {
+    return binary ? 'binary' : this.defaultTextEncoding
+  }
+
+  parseChecksumFile (data) {
+    let that = this
+    return new Promise((resolve, reject) => {
+      debug('Parsing checksum file')
+      that.checksums = {}
+      let lineNumber = 0
+      data.trim().split(/[\r\n]+/).forEach(line => {
+        lineNumber += 1
+        let result = CHECKSUM_LINE.exec(line)
+        if (result === null) {
+          debug(`Could not parse line number ${lineNumber}`)
+          reject(new ChecksumParseError(lineNumber, line))
+        } else {
+          // destructuring isn't available until Node 6
+          let filename = result[3]
+          let isBinary = result[2] === '*'
+          let checksum = result[1]
+
+          that.checksums[filename] = [checksum, isBinary]
+        }
+      })
+      debug('Parsed checksums:', that.checksums)
+      resolve()
+    })
+  }
+
+  readFile (filename, binary) {
+    debug(`Reading "${filename} (binary mode: ${binary})"`)
+    return new Promise((resolve, reject) => {
+      fs.readFile(filename, this.encoding(binary), (err, data) => {
+        if (err) {
+          reject(err)
+        } else {
+          resolve(data)
+        }
+      })
+    })
+  }
+
+  validate (baseDir, filesToCheck) {
+    if (typeof filesToCheck === 'string') {
+      filesToCheck = [filesToCheck]
+    }
+
+    return this.readFile(this.checksumFilename, false)
+      .then(this.parseChecksumFile.bind(this))
+      .then(() => {
+        return this.validateFiles(baseDir, filesToCheck)
+      })
+  }
+
+  validateFile (baseDir, filename) {
+    return new Promise((resolve, reject) => {
+      debug(`validateFile: ${filename}`)
+
+      let metadata = this.checksums[filename]
+      if (!metadata) {
+        return reject(new NoChecksumFoundError(filename))
+      }
+
+      // destructuring isn't available until Node 6
+      let checksum = metadata[0]
+      let binary = metadata[1]
+
+      let fullPath = path.resolve(baseDir, filename)
+      debug(`Reading file with "${this.encoding(binary)}" encoding`)
+      let stream = fs.createReadStream(fullPath, {encoding: this.encoding(binary)})
+      let hasher = crypto.createHash(this.algorithm, {defaultEncoding: 'binary'})
+      hasher.on('readable', () => {
+        let data = hasher.read()
+        if (data) {
+          let calculated = data.toString('hex')
+
+          debug(`Expected checksum: ${checksum}; Actual: ${calculated}`)
+          if (calculated === checksum) {
+            resolve()
+          } else {
+            reject(new ChecksumMismatchError(filename))
+          }
+        }
+      })
+      stream.pipe(hasher)
+    })
+  }
+
+  validateFiles (baseDir, filesToCheck) {
+    let that = this
+    return Promise.all(filesToCheck.map((filename) => {
+      return that.validateFile(baseDir, filename)
+    }))
+  }
+}
+
+let sumchecker = function sumchecker (algorithm, checksumFilename, baseDir, filesToCheck) {
+  return new ChecksumValidator(algorithm, checksumFilename).validate(baseDir, filesToCheck)
+}
+
+sumchecker.ChecksumMismatchError = ChecksumMismatchError
+sumchecker.ChecksumParseError = ChecksumParseError
+sumchecker.ChecksumValidator = ChecksumValidator
+sumchecker.NoChecksumFoundError = NoChecksumFoundError
+
+module.exports = sumchecker