diff --git a/.eslintrc.js b/.eslintrc.js
new file mode 100644
index 0000000..a8149a8
--- /dev/null
+++ b/.eslintrc.js
@@ -0,0 +1,27 @@
+module.exports = {
+    "env": {
+        "browser": true,
+        "commonjs": true,
+        "es6": true,
+        "node": true
+    },
+    "extends": "eslint:recommended",
+    "rules": {
+        "indent": [
+            "error",
+            2
+        ],
+        "linebreak-style": [
+            "error",
+            "unix"
+        ],
+        "quotes": [
+            "error",
+            "single"
+        ],
+        "semi": [
+            "error",
+            "always"
+        ]
+    }
+};
diff --git a/.jscsrc b/.jscsrc
new file mode 100644
index 0000000..8ff0e32
--- /dev/null
+++ b/.jscsrc
@@ -0,0 +1,46 @@
+{
+  "disallowKeywordsOnNewLine": [ "else" ],
+  "disallowMixedSpacesAndTabs": true,
+  "disallowMultipleLineStrings": true,
+  "disallowMultipleVarDecl": true,
+  "disallowNewlineBeforeBlockStatements": true,
+  "disallowQuotedKeysInObjects": true,
+  "disallowSpaceAfterObjectKeys": true,
+  "disallowSpaceAfterPrefixUnaryOperators": true,
+  "disallowSpaceBeforePostfixUnaryOperators": true,
+  "disallowSpacesInCallExpression": true,
+  "disallowTrailingComma": true,
+  "disallowTrailingWhitespace": true,
+  "disallowYodaConditions": true,
+
+  "requireCommaBeforeLineBreak": true,
+  "requireOperatorBeforeLineBreak": true,
+  "requireSpaceAfterBinaryOperators": true,
+  "requireSpaceAfterKeywords": [ "if", "for", "while", "else", "try", "catch" ],
+  "requireSpaceAfterLineComment": true,
+  "requireSpaceBeforeBinaryOperators": true,
+  "requireSpaceBeforeBlockStatements": true,
+  "requireSpaceBeforeKeywords": [ "else", "catch" ],
+  "requireSpaceBeforeObjectValues": true,
+  "requireSpaceBetweenArguments": true,
+  "requireSpacesInAnonymousFunctionExpression": {
+    "beforeOpeningCurlyBrace": true
+  },
+  "requireSpacesInFunctionDeclaration": {
+    "beforeOpeningCurlyBrace": true
+  },
+  "requireSpacesInFunctionExpression": {
+    "beforeOpeningCurlyBrace": true
+  },
+  "requireSpacesInConditionalExpression": true,
+  "requireSpacesInForStatement": true,
+  "requireSpacesInsideArrayBrackets": "all",
+  "requireSpacesInsideObjectBrackets": "all",
+  "requireDotNotation": false,
+
+  "maximumLineLength": 80,
+  "validateIndentation": 2,
+  "validateLineBreaks": "LF",
+  "validateParameterSeparator": ", ",
+  "validateQuoteMarks": "'"
+}
diff --git a/Makefile b/Makefile
new file mode 100644
index 0000000..cb3e106
--- /dev/null
+++ b/Makefile
@@ -0,0 +1,16 @@
+SRC_FILES=
+SRC_FILES+= lib/*.js
+SRC_FILES+= lib/**/*.js
+SRC_FILES+= lib/**/**/*.js
+SRC_FILES+= lib/**/**/**/*.js
+
+SRC_FILES+= bin/gyp
+SRC_FILES+= test/*.js
+
+lint:
+	eslint $(SRC_FILES)
+
+format:
+	eslint --fix $(SRC_FILES)
+
+.PHONY: lint format
diff --git a/lib/gyp.js b/lib/gyp.js
index 4e32ffa..7ddae65 100644
--- a/lib/gyp.js
+++ b/lib/gyp.js
@@ -43,7 +43,7 @@ function debugOutput(mode, message) {
       throw new Error('');
     } catch (e) {
       const prefix = e.stack.split('\n')[2].replace(/^\s*at\s*/g, '');
-      console.log(`${mode.toUpperCase()}:${prefix} ${message}`);
+      gyp.bindings.log(`${mode.toUpperCase()}:${prefix} ${message}`);
     }
   }
 }
@@ -79,7 +79,7 @@ function load(buildFiles, format, defaultVariables = {}, includes = [],
    * named WITH_CAPITAL_LETTERS to provide a distinct "best practice" namespace,
    * avoiding collisions with user and automatic variables.
    */
-  defaultVariables['GENERATOR'] = format
+  defaultVariables['GENERATOR'] = format;
   defaultVariables['GENERATOR_FLAVOR'] = params['flavor'] || '';
 
   /* Format can be a custom JS file, or by default the name of a module
@@ -136,7 +136,7 @@ function load(buildFiles, format, defaultVariables = {}, includes = [],
       buildFiles, defaultVariables, includes.slice(),
       depth, generatorInputInfo, check, circularCheck,
       duplicateBasenameCheck,
-      params['root_targets'])
+      params['root_targets']);
   return [ generator ].concat(result);
 }
 
@@ -173,105 +173,6 @@ function shlexEnv(envName) {
   return flags || [];
 }
 
-function formatOpt(opt, value) {
-  if (/^--/.test(opt))
-    return `${opt}=${value}`;
-  return opt + value;
-}
-
-function regenerateAppendFlag(flag, values, predicate, envName, options) {
-  /*
-   * Regenerate a list of command line flags, for an option of action='append'.
-   * The |env_name|, if given, is checked in the environment and used to
-   * generate an initial list of options, then the options that were specified
-   * on the command line (given in |values|) are appended.  This matches the
-   * handling of environment variables and command line flags where command line
-   * flags override the environment, while not requiring the environment to be
-   * set when the flags are used again.
-   */
-
-  const flags = [];
-  if (options.use_environment && envName) {
-    const s = shlexEnv(envName);
-    for (let i = 0; i < s.length;i++) {
-      const flagValue = s[i];
-      const value = formatOpt(flag, predicate(flagValue));
-
-      const index = flags.indexOf(value);
-      if (index !== -1)
-        flags.splice(index, 1);
-
-      flags.push(value);
-    }
-  }
-  if (values) {
-    for (let i = 0; i < values.length; i++) {
-      const flagValue = values[i];
-      flags.push(formatOpt(flag, predicate(flagValue)));
-    }
-  }
-  return flags;
-}
-
-function regenerateFlags(options) {
-  /* Given a parsed options object, and taking the environment variables into
-   * account, returns a list of flags that should regenerate an equivalent
-   * options object (even in the absence of the environment variables.)
-   *
-   * Any path options will be normalized relative to depth.
-   *
-   * The format flag is not included, as it is assumed the calling generator
-   * will set that as appropriate.
-   */
-  function fixPath(path) {
-    path = gyp.common.fixIfRelativePath(path, options.depth);
-
-    // PORT: os.path.curdir
-    if (!path)
-      return '.';
-    return path;
-  }
-
-  function noop(value) {
-    return value;
-  }
-
-  // We always want to ignore the environment when regenerating, to avoid
-  // duplicate or changed flags in the environment at the time of regeneration.
-  const flags = [ '--ignore-environment' ];
-  const meta = options._regenerationMetadata;
-  Object.keys(meta).forEach((name) => {
-    const metadata = meta[name];
-
-    const opt = metadata['opt'];
-    const value = options.name;
-    const valuePredicate = metadata['type'] === 'path' ? fixPath : noop;
-    const action = metadata['action'];
-    const envName = metadata['envName'];
-    if (action === 'append') {
-      flags = flags.concat(regenerateAppendFlag(opt, value, valuePredicate,
-                                                envName, options));
-    } else if (action === 'store' || !action) {
-      if (value)
-        flags.push(formatOpt(opt, valuePredicate(value)));
-      else if (options.use_environment && envName && process.env[envName])
-        flags.push(formatOpt(opt, valuePredicate(process.env[envName])));
-    } else if (action === 'store_true' || action === 'store_false') {
-      if (action === 'store_true' && value ||
-          action === 'store_false' && !value) {
-        flags.append(opt);
-      } else if (options.use_environment && envName) {
-        console.error(`Warning: environment regeneration unimplemented for ` +
-                      `${action} flag "${opt}" env_name "${envName}"`);
-      }
-    } else {
-      console.error(`Warning: regeneration unimplemented for action ` +
-                    `${action} flag "${opt}"`);
-    }
-  });
-  return flags;
-}
-
 function RegeneratableOptionParser() {
   this.options = {};
   this.letters = {};
@@ -333,7 +234,7 @@ RegeneratableOptionParser.prototype.setUsage = function setUsage(usage) {
 };
 
 RegeneratableOptionParser.prototype.printHelp = function printHelp() {
-  console.error(this.usage);
+  gyp.bindings.error(this.usage);
   let max = 0;
 
   Object.keys(this.options).forEach((name) => {
@@ -356,7 +257,7 @@ RegeneratableOptionParser.prototype.printHelp = function printHelp() {
       desc += ' ';
 
     desc += `${option.help}`;
-    console.error(desc);
+    gyp.bindings.error(desc);
   });
   process.exit(0);
 };
@@ -498,9 +399,9 @@ gyp.main = function main(args) {
    * deprecated.
    */
   parser.addOption('no-duplicate-basename-check', {
-                   dest: 'duplicate_basename_check', action: 'store_false',
-                   default: true, regenerate: false,
-                   help: 'don\'t check for duplicate basenames' });
+    dest: 'duplicate_basename_check', action: 'store_false',
+    default: true, regenerate: false,
+    help: 'don\'t check for duplicate basenames' });
   parser.addOption('suffix', 'S', { dest: 'suffix', default: '',
                    help: 'suffix to add to generated files' });
   parser.addOption('toplevel-dir', { dest: 'toplevel_dir', action: 'store',
@@ -564,7 +465,7 @@ gyp.main = function main(args) {
 
   // Do an extra check to avoid work when we're not debugging.
   if (gyp.debug[DEBUG_GENERAL]) {
-    debugOutput(DEBUG_GENERAL, 'running with these options:')
+    debugOutput(DEBUG_GENERAL, 'running with these options:');
     Object.keys(options).sort().forEach((option) => {
       const value = options[option];
       if (option[0] === '_')
@@ -609,7 +510,7 @@ gyp.main = function main(args) {
   if (homeDotGyp) {
     const defaultInclude = path.join(homeDotGyp, 'include.gypi');
     if (fs.existsSync(defaultInclude)) {
-      console.log(`Using overrides found in ${defaultInclude}`);
+      gyp.bindings.log(`Using overrides found in ${defaultInclude}`);
       includes.push(defaultInclude);
     }
   }
diff --git a/lib/gyp/bindings.js b/lib/gyp/bindings.js
index 6d68a2f..b46c8fb 100644
--- a/lib/gyp/bindings.js
+++ b/lib/gyp/bindings.js
@@ -1,6 +1,5 @@
 'use strict';
 
-const util = require('util');
 const path = require('path');
 const fs = require('fs');
 const execSync = require('child_process').execSync;
@@ -34,3 +33,11 @@ exports.process = {
   platform: process.platform,
   exit: (code) => process.exit(code)
 };
+
+exports.log = function log(message) {
+  process.stdout.write(message + '\n');
+};
+
+exports.error = function error(message) {
+  process.stderr.write(message + '\n');
+};
diff --git a/lib/gyp/common.js b/lib/gyp/common.js
index 1697f13..2f29215 100644
--- a/lib/gyp/common.js
+++ b/lib/gyp/common.js
@@ -232,32 +232,34 @@ function parseQualifiedTarget(target) {
   // NOTE: rsplit is used to disambiguate the Windows drive letter separator.
   let buildFile;
   if (/:/.test(target)) {
-    let _;
-    [ _, buildFile, target ] = target.match(/^(.*?)(?::([^:]*))?$/);
+    const match = target.match(/^(.*?)(?::([^:]*))?$/);
+    buildFile = match[1];
+    target = match[2];
   } else {
     buildFile = undefined;
   }
 
   let toolset;
   if (/#/.test(target)) {
-    let _;
-    [ _, target, toolset ] = target.match(/^(.*?)(?:#([^:]*))?$/);
+    const match = target.match(/^(.*?)(?:#([^:]*))?$/);
+    target = match[1];
+    toolset = match[2];
   } else {
     toolset = undefined;
   }
 
   return [ buildFile, target, toolset ];
-};
+}
 exports.parseQualifiedTarget = parseQualifiedTarget;
 
-exports.findQualifiedTargets = function findQualifiedTargets(target, flatList) {
+exports.findQualifiedTargets = function findQualifiedTargets() {
   throw new Error('Not implemented');
 };
 
 exports.buildFile = function (fullyQualifiedTarget) {
   // Extracts the build file from the fully qualified target.
   return parseQualifiedTarget(fullyQualifiedTarget)[0];
-}
+};
 
 //
 // Python shims
diff --git a/lib/gyp/generator/ninja/index.js b/lib/gyp/generator/ninja/index.js
index dad18a2..3cb9027 100644
--- a/lib/gyp/generator/ninja/index.js
+++ b/lib/gyp/generator/ninja/index.js
@@ -4,7 +4,6 @@ const gyp = require('../../../gyp');
 const Writer = require('./writer');
 
 const path = gyp.bindings.path;
-const fs = gyp.bindings.fs;
 const process = gyp.bindings.process;
 
 const generatorDefaultVariables = {
@@ -50,7 +49,7 @@ exports.generatorFilelistPaths = undefined;
 exports.generatorSupportsMultipleToolsets = gyp.common.crossCompileRequested();
 
 
-function calculateVariables(defaultVariables, params) {
+function calculateVariables(defaultVariables) {
   function setdef(key, val) {
     if (!defaultVariables.hasOwnProperty(key))
       defaultVariables[key] = val;
@@ -64,11 +63,11 @@ function calculateVariables(defaultVariables, params) {
     setdef('LIB_DIR', generatorDefaultVariables['PRODUCT_DIR']);
   } else if (process.platform === 'win32') {
     // TODO(indutny): MSVS_VERSION, MSVS_OS_BITS
-    setdef('OS', 'win')
+    setdef('OS', 'win');
     defaultVariables['EXECUTABLE_SUFFIX'] = '.exe';
-    defaultVariables['STATIC_LIB_PREFIX'] = ''
+    defaultVariables['STATIC_LIB_PREFIX'] = '';
     defaultVariables['STATIC_LIB_SUFFIX'] = '.lib';
-    defaultVariables['SHARED_LIB_PREFIX'] = ''
+    defaultVariables['SHARED_LIB_PREFIX'] = '';
     defaultVariables['SHARED_LIB_SUFFIX'] = '.dll';
   } else {
     setdef('OS', process.platform);
@@ -76,10 +75,10 @@ function calculateVariables(defaultVariables, params) {
     setdef('SHARED_LIB_DIR', path.join('$!PRODUCT_DIR', 'lib'));
     setdef('LIB_DIR', path.join('$!PRODUCT_DIR', 'obj'));
   }
-};
+}
 exports.calculateVariables = calculateVariables;
 
-function Ninja({ index, outDir, target, targetDict, ninjas, config } = extra) {
+function Ninja({ index, outDir, target, targetDict, ninjas, config }) {
   const [ buildFile, targetName, toolset ] =
       gyp.common.parseQualifiedTarget(target);
 
@@ -87,7 +86,7 @@ function Ninja({ index, outDir, target, targetDict, ninjas, config } = extra) {
   if (toolset !== 'target')
     obj += '.' + toolset;
 
-  this.index = 0;
+  this.index = index;
   this.ninjas = ninjas;
   this.config = config;
 
@@ -162,7 +161,6 @@ Ninja.prototype.type = function type() {
 };
 
 Ninja.prototype.output = function output() {
-  const targetDict = this.targetDict;
   let res = [];
 
   let vars = gyp.common.shallowCopy(generatorDefaultVariables);
@@ -272,7 +270,7 @@ Ninja.prototype.vars = function vars() {
   // TODO(indutny): library_dirs
   libs = libs.concat(targetDict.libraries || []);
   if (this.flavor === 'win32') {
-    libs = gyp.platform.win.adjustLibraries(libs)
+    libs = gyp.platform.win.adjustLibraries(libs);
   }
   const prepare = (list) => {
     return list.map(v => this.expand(v)).join(' ').trim();
@@ -563,8 +561,8 @@ NinjaMain.prototype.defaults = function defaults() {
 
   this.params.build_files.forEach((buildFile) => {
     this.targetList.forEach((target) => {
-      const [ targetBuildFile, _1, _2 ] =
-          gyp.common.parseQualifiedTarget(target);
+      const targetBuildFile =
+          gyp.common.parseQualifiedTarget(target)[0];
       if (targetBuildFile !== buildFile)
         return;
 
@@ -579,7 +577,7 @@ NinjaMain.prototype.defaults = function defaults() {
   main.sectionEnd('defaults');
 
   main.finalize();
-}
+};
 
 exports.generateOutput = function generateOutput(targetList, targetDicts, data,
                                                  params) {
diff --git a/lib/gyp/input.js b/lib/gyp/input.js
index dcbb848..5414bfa 100644
--- a/lib/gyp/input.js
+++ b/lib/gyp/input.js
@@ -32,7 +32,7 @@ const basePathSections = [
   'inputs',
   'libraries',
   'outputs',
-  'sources',
+  'sources'
 ];
 let pathSections = {};
 
@@ -299,7 +299,7 @@ function processToolsetsInDict(data) {
           newTarget['toolset'] = build;
           newTargetList.push(target);
         });
-        target['toolset'] = toolsets[0]
+        target['toolset'] = toolsets[0];
         newTargetList.push(target);
       }
     });
@@ -385,11 +385,11 @@ function loadTargetBuildFile(buildFilePath, data, auxData, variables, includes,
 
   // Apply "pre"/"early" variable expansions and condition evaluations.
   processVariablesAndConditionsInDict(
-      buildFileData, 'PHASE_EARLY', variables, buildFilePath)
+      buildFileData, 'PHASE_EARLY', variables, buildFilePath);
 
   // Since some toolsets might have been defined conditionally, perform
   // a second round of toolsets expansion now.
-  processToolsetsInDict(buildFileData)
+  processToolsetsInDict(buildFileData);
 
   // Look at each project's target_defaults dict, and merge settings into
   // targets.
@@ -567,7 +567,7 @@ function expandVariables(input, phase, variables, buildFile) {
   } else if (phase === 'PHASE_LATELATE') {
     variableRe = LATELATE_VARIABLE_RE;
   } else {
-    throw new Error(`Unexpected phase: ${PHASE}`);
+    throw new Error(`Unexpected phase: ${phase}`);
   }
 
   let inputStr = String(input);
@@ -746,7 +746,12 @@ function expandVariables(input, phase, variables, buildFile) {
 
           let p;
           try {
-            p = execSync(contents);
+            if (useShell) {
+              p = execSync(contents);
+            } else {
+              // TODO(indutny): implement me
+              throw new Error('Array commands not implemented yet');
+            }
           } catch (e) {
             e.message += `\nCall to '${contents} failed while in ${buildFile}`;
             throw e;
@@ -907,7 +912,7 @@ function evalCondition(condition, conditionsKey, phase, variables, buildFile) {
     const trueDict = condition[i + 1];
 
     if (typeof trueDict !== 'object') {
-      throw new Error(`${conditionsKey} ${condExpr} must be followed by a `
+      throw new Error(`${conditionsKey} ${condExpr} must be followed by a ` +
                       `dictionary, not ${typeof trueDict}`);
     }
 
@@ -948,7 +953,7 @@ function evalSingleCondition(condExpr, trueDict, falseDict, phase, variables,
                                            buildFile);
   if (typeof condExprExpanded !== 'string' &&
       typeof condExprExpanded !== 'number') {
-    throw new Error(`Variable expansion in this context permits str and int ` +
+    throw new Error('Variable expansion in this context permits str and int ' +
                     `only, found ${typeof condExprExpanded}`);
   }
 
@@ -1044,7 +1049,7 @@ function loadVariablesFromVariablesDict(variables, theDict, theDictKey) {
     return;
 
   Object.keys(vars).forEach((key) => {
-    const value = vars[key];
+    let value = vars[key];
     if (typeof value !== 'string' &&
         typeof value !== 'number' &&
         !Array.isArray(value)) {
@@ -1112,7 +1117,7 @@ function processVariablesAndConditionsInDict(theDict, phase, variablesIn,
       const expanded = expandVariables(value, phase, variables, buildFile);
       if (typeof expanded !== 'string' && typeof expanded !== 'number') {
         throw new Error(
-            `Variable expansion in this context permits str and int ` +
+            'Variable expansion in this context permits str and int ' +
             `only, found ${typeof expanded} for ${key}`);
       }
       theDict[key] = expanded;
@@ -1216,7 +1221,7 @@ function processVariablesAndConditionsInList(theList, phase, variables,
         continue;
       } else {
         throw new Error(
-            `Variable expansion in this context permits strings and ` +
+            'Variable expansion in this context permits strings and ' +
             `lists only, found ${typeof expanded} at ${index}`);
       }
     } else if (typeof item !== 'number') {
@@ -1319,8 +1324,8 @@ function expandWildcardDependencies(targets, data) {
    */
 
   Object.keys(targets).forEach((target) => {
+    // TODO(indutny): toolsets?
     const targetDict = targets[target];
-    const toolset = targetDict['toolset'];
     const targetBuildFile = gyp.common.buildFile(target);
 
     dependencySections.forEach((dependencyKey) => {
@@ -1531,7 +1536,7 @@ DependencyGraphNode.prototype.flattenToList = function flattenToList() {
   }
 
   return Array.from(flatList.values());
-}
+};
 
 DependencyGraphNode.prototype.findCycles = function findCycles() {
   /*
@@ -1544,7 +1549,7 @@ DependencyGraphNode.prototype.findCycles = function findCycles() {
     node.dependents.forEach((child) => {
       const i = path.indexOf(child);
       if (i !== -1) {
-        results.push([ child ].concat(path.slice(0, index + 1)));
+        results.push([ child ].concat(path.slice(0, i + 1)));
       } else {
         visited.add(child);
         visit(child, [ child ].concat(path));
@@ -1558,8 +1563,8 @@ DependencyGraphNode.prototype.findCycles = function findCycles() {
   return results;
 };
 
-DependencyGraphNode.prototype.directDependencies =
-    function directDependencies(dependencies) {
+
+function directDependencies(dependencies) {
   // Returns a list of just direct dependencies.
   if (!dependencies)
     dependencies = [];
@@ -1571,10 +1576,10 @@ DependencyGraphNode.prototype.directDependencies =
   });
 
   return dependencies;
-};
+}
+DependencyGraphNode.prototype.directDependencies = directDependencies;
 
-DependencyGraphNode.prototype._addImportedDependencies =
-    function _addImportedDependencies(targets, dependencies) {
+function _addImportedDependencies(targets, dependencies) {
   /* Given a list of direct dependencies, adds indirect dependencies that
    * other dependencies have declared to export their settings.
    *
@@ -1605,8 +1610,8 @@ DependencyGraphNode.prototype._addImportedDependencies =
     // dependency that exported them.  This is done to more closely match
     // the depth-first method used by DeepDependencies.
     let addIndex = 1;
-    (dependencyDict['export_dependent_settings'] || [])
-        .forEach((importedDependency) => {
+    const exportSettings = dependencyDict['export_dependent_settings'] || [];
+    exportSettings.forEach((importedDependency) => {
       if (dependencies.indexOf(importedDependency) === -1) {
         dependencies.splice(index + addIndex, 0, importedDependency);
         addIndex++;
@@ -1616,20 +1621,22 @@ DependencyGraphNode.prototype._addImportedDependencies =
   }
 
   return dependencies;
-};
+}
+DependencyGraphNode.prototype._addImportedDependencies =
+    _addImportedDependencies;
 
-DependencyGraphNode.prototype.directAndImportedDependencies =
-    function directAndImportedDependencies(targets, dependencies) {
+function directAndImportedDependencies(targets, dependencies) {
   /* Returns a list of a target's direct dependencies and all indirect
    * dependencies that a dependency has advertised settings should be exported
    * through the dependency for.
    */
   dependencies = this.directDependencies(dependencies);
   return this._addImportedDependencies(targets, dependencies);
-};
+}
+DependencyGraphNode.prototype.directAndImportedDependencies =
+    directAndImportedDependencies;
 
-DependencyGraphNode.prototype.deepDependencies =
-    function deepDependencies(dependencies) {
+function deepDependencies(dependencies) {
   /* Returns an OrderedSet of all of a target's dependencies, recursively. */
   if (!dependencies) {
     // Using a list to get ordered output and a set to do fast "is it
@@ -1650,11 +1657,11 @@ DependencyGraphNode.prototype.deepDependencies =
   });
 
   return dependencies;
-};
+}
+DependencyGraphNode.prototype.deepDependencies = deepDependencies;
 
-DependencyGraphNode.prototype._linkDependenciesInternal =
-    function _linkDependenciesInternal(targets, includeSharedLibraries,
-                                       dependencies, initial = true) {
+function _linkDependenciesInternal(targets, includeSharedLibraries,
+                                   dependencies, initial = true) {
   /* Returns an OrderedSet of dependency targets that are linked
    * into this target.
    *
@@ -1688,7 +1695,7 @@ DependencyGraphNode.prototype._linkDependenciesInternal =
     throw new Error('Missing \'target_name\' field in target.');
 
   if (!targets[this.ref].hasOwnProperty('type')) {
-    throw new Error(`Missing 'type' field in target ` +
+    throw new Error('Missing \'type\' field in target ' +
                     `${targets[this.ref]['target_name']}`);
   }
 
@@ -1753,10 +1760,11 @@ DependencyGraphNode.prototype._linkDependenciesInternal =
   }
 
   return dependencies;
-};
+}
+DependencyGraphNode.prototype._linkDependenciesInternal =
+    _linkDependenciesInternal;
 
-DependencyGraphNode.prototype.dependenciesForLinkSettings =
-    function dependenciesForLinkSettings(targets) {
+function dependenciesForLinkSettings(targets) {
   /*
    * Returns a list of dependency targets whose link_settings should be merged
    * into this target.
@@ -1769,23 +1777,25 @@ DependencyGraphNode.prototype.dependenciesForLinkSettings =
   const includeSharedLibraries =
       targets[this.ref]['allow_sharedlib_linksettings_propagation'] !== false;
   return this._linkDependenciesInternal(targets, includeSharedLibraries);
-};
+}
+DependencyGraphNode.prototype.dependenciesForLinkSettings =
+    dependenciesForLinkSettings;
 
-DependencyGraphNode.prototype.dependenciesToLinkAgainst =
-    function dependenciesToLinkAgainst(targets) {
+function dependenciesToLinkAgainst(targets) {
   /*
    * Returns a list of dependency targets that are linked into this target.
    */
 
   return this._linkDependenciesInternal(targets, true);
-};
+}
+DependencyGraphNode.prototype.dependenciesToLinkAgainst =
+    dependenciesToLinkAgainst;
 
 function buildDependencyList(targets) {
   // Create a DependencyGraphNode for each target.  Put it into a dict for easy
   // access.
   const dependencyNodes = {};
   Object.keys(targets).forEach((target) => {
-    const spec = targets[target];
     if (!dependencyNodes.hasOwnProperty(target))
       dependencyNodes[target] = new DependencyGraphNode(target);
   });
@@ -1805,7 +1815,7 @@ function buildDependencyList(targets) {
       dependencies.forEach((dependency) => {
         const dependencyNode = dependencyNodes[dependency];
         if (!dependencyNode) {
-          throw new Error(`Dependency '${dependency}' not found while `
+          throw new Error(`Dependency '${dependency}' not found while ` +
                           `trying to load target ${target}`);
         }
         // TODO(indutny): method for this
@@ -1887,7 +1897,7 @@ function verifyNoGYPFileCircularDependencies(targets) {
 
   // Files that have no dependencies are treated as dependent on root_node.
   const rootNode = new DependencyGraphNode(undefined);
-  dependencyNodes.forEach((buildFileNode, k) => {
+  dependencyNodes.forEach((buildFileNode) => {
     if (buildFileNode.dependencies.length === 0) {
       buildFileNode.dependencies.push(rootNode);
       rootNode.dependents.push(buildFileNode);
@@ -1936,7 +1946,7 @@ function doDependentSettings(key, flatList, targets, dependencyNodes) {
       dependencies =
           dependencyNodes[target].dependenciesForLinkSettings(targets);
     } else {
-      throw new Error(`DoDependentSettings doesn't know how to determine ` +
+      throw new Error('DoDependentSettings doesn\'t know how to determine ' +
                       `dependencies for ${key}`);
     }
 
@@ -2024,8 +2034,8 @@ function adjustStaticLibraryDependencies(flatList, targets, dependencyNodes,
       // Note: flat_list is already sorted in the order from dependencies to
       // dependents.
       if (sortDependencies && targetDict.hasOwnProperty('dependencies')) {
-        targetDict['dependencies'] = flatList.slice().reverse()
-            .filter((dep) => {
+        const deps = flatList.slice().reverse();
+        targetDict['dependencies'] = deps.filter((dep) => {
           return targetDict['dependencies'].indexOf(dep) !== -1;
         });
       }
@@ -2169,7 +2179,7 @@ function mergeDicts(to, fro, toFile, froFile) {
 
       if (badMerge) {
         throw TypeError(
-            `Attempt to merge dict value of type $[typeof v} ` +
+            `Attempt to merge dict value of type ${typeof v} ` +
             `into incompatible type ${typeof to[k]} ` +
             `for key ${k}`);
       }
@@ -2257,7 +2267,7 @@ function mergeDicts(to, fro, toFile, froFile) {
       mergeDicts(to[k], v, toFile, froFile);
     } else {
       throw new Error(
-          `Attempt to merge dict value of unsupported type `
+          'Attempt to merge dict value of unsupported type ' +
           `${typeof v} for key ${k}`);
     }
   });
@@ -2369,7 +2379,7 @@ function setUpConfigurations(target, targetDict) {
       keyBase = key.slice(0, -1);
     else
       keyBase = key;
-    if (nonConfigurationKeys.indexOf(key) === -1)
+    if (nonConfigurationKeys.indexOf(keyBase) === -1)
       deleteKeys.push(key);
   });
   deleteKeys.forEach((key) => {
@@ -2423,7 +2433,7 @@ function processListFiltersInDict(name, theDict) {
   const lists = [];
   const delLists = [];
   Object.keys(theDict).forEach((key) => {
-    const value = theDict[key];
+    let value = theDict[key];
     const operation = key[key.length - 1];
     if (operation !== '!' && operation !== '/')
       return;
@@ -2597,8 +2607,8 @@ function validateTargetType(target, targetDict) {
   if (targetDict['standalone_static_library'] &&
       targetType !== 'static_library') {
     throw new Error(`Target ${target} has type ${targetType} but ` +
-                    `standalone_static_library flag is only valid for ` +
-                    `static_library type.`);
+                    'standalone_static_library flag is only valid for ' +
+                    'static_library type.');
   }
 }
 
@@ -2633,11 +2643,11 @@ function validateSourcesInTarget(target, targetDict, buildFile,
   });
 
   if (error) {
-    console.log(
-      `static library ${target} has several files with the same basename:\n` +
-      error +
-      `libtool on Mac cannot handle that. Use --no-duplicate-basename-check ` +
-      `to disable this validation.`);
+    gyp.bindings.log(
+        `static library ${target} has several files with the same basename:\n` +
+        error +
+        'libtool on Mac cannot handle that. Use ' +
+        '--no-duplicate-basename-check to disable this validation.');
     throw new Error('Duplicate basenames in sources section, see list above');
   }
 }
@@ -2679,7 +2689,7 @@ function validateRulesInTarget(target, targetDict, extraSourcesForRules) {
     // Make sure rule_sources isn't already there.  It's going to be
     // created below if needed.
     if (rule.hasOwnProperty('rule_sources')) {
-      throw new Error(`rule_sources must not exists in input, ` +
+      throw new Error('rule_sources must not exists in input, ' +
                       `target ${target}, rule ${ruleName}`);
     }
 
@@ -2688,7 +2698,7 @@ function validateRulesInTarget(target, targetDict, extraSourcesForRules) {
     sourceKeys.forEach((sourceKey) => {
       (targetDict[sourceKey] || []).forEach((source) => {
         // PORT: os.path.splitext
-        let [ sourceRoot, sourceExtension ] = gyp.common.splitext(source);
+        let sourceExtension = path.extname(source);
         if (sourceExtension[0] === '.')
           sourceExtension = sourceExtension.slice(1);
         if (sourceExtension === ruleExtension)
@@ -2721,18 +2731,18 @@ function validateRunAsInTarget(target, targetDict, buildFile) {
   }
   const workingDirectory = runAs['working_directory'];
   if (workingDirectory && typeof workingDirectory !== 'string') {
-    throw new Error(`The 'working_directory' for 'run_as' in target ` +
+    throw new Error('The \'working_directory\' for \'run_as\' in target ' +
                     `${targetName} from file ${buildFile} should be a string.`);
   }
   const environment = runAs['environment'];
   if (environment && typeof environment !== 'object') {
-    throw new Error(`The 'environment' for 'run_as' in target ` +
+    throw new Error('The \'environment\' for \'run_as\' in target ' +
                     `${targetName} from file ${buildFile} should be a ` +
-                    `dictionary.`);
+                    'dictionary.');
   }
 }
 
-function validateActionsInTarget(target, targetDict, buildFile) {
+function validateActionsInTarget(target, targetDict) {
   /* Validates the inputs to the actions in a target. */
   const targetName = targetDict['target_name'];
   const actions = targetDict['actions'] || [];
@@ -2740,7 +2750,7 @@ function validateActionsInTarget(target, targetDict, buildFile) {
     const actionName = action['action_name'];
     if (!actionName) {
       throw new Error(`Anonymous action in target ${targetName}.  ` +
-                      `An action must have an 'action_name' field.`);
+                      'An action must have an \'action_name\' field.');
     }
     const inputs = action['inputs'];
     if (!inputs)
@@ -2840,7 +2850,9 @@ function verifyNoCollidingTargets(targets) {
   targets.forEach((target) => {
     // Separate out 'path/to/file.gyp, 'target_name' from
     // 'path/to/file.gyp:target_name'.
-    const [ _, tpath, name ] = target.match(/^(.*?)(?::([^:]*))?$/);
+    const match = target.match(/^(.*?)(?::([^:]*))?$/);
+    const tpath = match[1];
+    const name = match[2];
     // Separate out 'path/to', 'file.gyp' from 'path/to/file.gyp'.
     let subdir = path.dirname(tpath);
     const gyp = path.basename(tpath);
@@ -2910,7 +2922,7 @@ function load(buildFiles, variables, includes, depth, generatorInputInfo, check,
   });
 
   // Build a dict to access each target's subdict by qualified name.
-  const targets = buildTargetsDict(data);
+  let targets = buildTargetsDict(data);
 
   // Fully qualify all dependency links.
   qualifyDependencies(targets);
@@ -2968,9 +2980,11 @@ function load(buildFiles, variables, includes, depth, generatorInputInfo, check,
   verifyNoCollidingTargets(flatList);
 
   // Handle dependent settings of various types.
-  [ 'all_dependent_settings',
+  [
+    'all_dependent_settings',
     'direct_dependent_settings',
-    'link_settings' ].forEach((settingsType) => {
+    'link_settings'
+  ].forEach((settingsType) => {
     doDependentSettings(settingsType, flatList, targets, dependencyNodes);
 
     // Take out the dependent settings now that they've been published to all
diff --git a/lib/gyp/platform/darwin.js b/lib/gyp/platform/darwin.js
index d5df64a..f4db074 100644
--- a/lib/gyp/platform/darwin.js
+++ b/lib/gyp/platform/darwin.js
@@ -13,7 +13,7 @@ darwin.compilerFlags = function compilerFlags(xc) {
   if (xc.CLANG_WARN_CONSTANT_CONVERSION === 'YES')
     cflags.push('-Wconstant-conversion');
   if (xc.GCC_CHAR_IS_UNSIGNED_CHAR === 'YES')
-    cflags.push('-funsigned-char')
+    cflags.push('-funsigned-char');
   if (xc.GCC_CW_ASM_SYNTAX !== 'NO')
     cflags.push('-fasm-blocks');
   if (xc.GCC_OPTIMIZATION_LEVEL)
@@ -25,7 +25,7 @@ darwin.compilerFlags = function compilerFlags(xc) {
   if (xc.ARCHS && xc.ARCHS.length === 1)
     cflags.push(`-arch ${xc.ARCHS[0]}`);
   else
-    cflags.push('-arch i386')
+    cflags.push('-arch i386');
 
   if (xc.GCC_C_LANGUAGE_STANDARD === 'ansi')
     cflags_c.push('-ansi');
diff --git a/lib/gyp/platform/unix.js b/lib/gyp/platform/unix.js
index 79b01d7..c67ad68 100644
--- a/lib/gyp/platform/unix.js
+++ b/lib/gyp/platform/unix.js
@@ -1,3 +1,5 @@
+'use strict';
+
 const gyp = require('../../gyp');
 
 const process = gyp.bindings.process;
@@ -26,8 +28,8 @@ unix.ninjaRules = function ninjaRules(n, useCxx) {
              `${useCxx ? '$ldflags_cc $cflags_cc' : '$ldflags_c $cflags_c'} ` +
              (process.platform === 'darwin' ?
                  '$in ' :
-                 `-Wl,--start-group $in -Wl,--end-group `) +
-             `$cflags -o $out $solibs $libs`,
+                 '-Wl,--start-group $in -Wl,--end-group ') +
+             '$cflags -o $out $solibs $libs',
     pool: 'link_pool',
     description: 'LINK $out'
   });
@@ -37,8 +39,8 @@ unix.ninjaRules = function ninjaRules(n, useCxx) {
              `${useCxx ? '$ldflags_cc $cflags_cc' : '$ldflags_c $cflags_c'} ` +
              (process.platform === 'darwin' ?
                  '$in ' :
-                 `-Wl,--start-group $in -Wl,--end-group `) +
-             `$cflags -o $out $solibs $libs`,
+                 '-Wl,--start-group $in -Wl,--end-group ') +
+             '$cflags -o $out $solibs $libs',
     pool: 'link_pool',
     description: 'SOLINK $out'
   });
diff --git a/lib/gyp/platform/win.js b/lib/gyp/platform/win.js
index 79645a7..8e6c64d 100644
--- a/lib/gyp/platform/win.js
+++ b/lib/gyp/platform/win.js
@@ -1,7 +1,5 @@
 'use strict';
 
-const gyp = require('../../gyp');
-
 const win = exports;
 
 win.ninjaRules = function ninjaRules(n) {
@@ -67,18 +65,18 @@ win.adjustLibraries = function adjustLibraries(libs) {
     const suffix = '.lib' + quoted;
     if (!lib.toLowerCase().endsWith(suffix))
       lib = lib.substr(0, lib.length - !!quoted) + suffix;
-    return lib
+    return lib;
   });
-}
+};
 
-function SettingsWrapper(settings, flags) {
+function settingsWrapper(settings, flags) {
   return function(name, options) {
     options = options || {};
     const append = function(value) {
       if (value !== undefined) {
         switch (typeof options.map) {
-          case 'function': value = options.map(value); break;
-          case 'object':   value = options.map[value]; break;
+        case 'function': value = options.map(value); break;
+        case 'object':   value = options.map[value]; break;
         }
         if (value !== undefined && options.prefix)
           value = options.prefix + value;
@@ -94,7 +92,7 @@ function SettingsWrapper(settings, flags) {
     } else {
       append(value);
     }
-  }
+  };
 }
 
 function expandMSBuildMacros(value) {
@@ -105,7 +103,7 @@ function expandMSBuildMacros(value) {
 function compilerFlags(compiler) {
   let cflags = [];
   if (compiler) {
-    let cl = SettingsWrapper(compiler, cflags);
+    let cl = settingsWrapper(compiler, cflags);
     cl('Optimization', {
       map: {'0': 'd', '1': '1', '2': '2', '3': 'x'},
       prefix: '/O', defvalue: '2' });
@@ -114,44 +112,44 @@ function compilerFlags(compiler) {
     cl('StringPooling', { map: {'true': '/GF'} });
     cl('EnableFiberSafeOptimizations', { map: {'true': '/GT'} });
     cl('OmitFramePointers', {
-      map: {'false': '-', 'true': ''}, prefix: '/Oy' })
+      map: {'false': '-', 'true': ''}, prefix: '/Oy' });
     cl('EnableIntrinsicFunctions', {
-      map: {'false': '-', 'true': ''}, prefix: '/Oi' })
+      map: {'false': '-', 'true': ''}, prefix: '/Oi' });
     cl('FavorSizeOrSpeed', {
-      map: {'1': 't', '2': 's'}, prefix: '/O' })
+      map: {'1': 't', '2': 's'}, prefix: '/O' });
     cl('FloatingPointModel', {
       map: {'0': 'precise', '1': 'strict', '2': 'fast'},
-      prefix: '/fp:', defvalue: '0' })
-    cl('WholeProgramOptimization', { map: {'true': '/GL'} })
-    cl('WarningLevel', { prefix: '/W' })
-    cl('WarnAsError', { map: {'true': '/WX'} })
+      prefix: '/fp:', defvalue: '0' });
+    cl('WholeProgramOptimization', { map: {'true': '/GL'} });
+    cl('WarningLevel', { prefix: '/W' });
+    cl('WarnAsError', { map: {'true': '/WX'} });
     cl('CallingConvention', {
       map: {'0': 'd', '1': 'r', '2': 'z', '3': 'v'},
-      prefix: '/G' })
+      prefix: '/G' });
     cl('DebugInformationFormat', {
-      map: {'1': '7', '3': 'i', '4': 'I'}, prefix: '/Z' })
-    cl('RuntimeTypeInfo', { map: {'true': '/GR', 'false': '/GR-'} })
+      map: {'1': '7', '3': 'i', '4': 'I'}, prefix: '/Z' });
+    cl('RuntimeTypeInfo', { map: {'true': '/GR', 'false': '/GR-'} });
     cl('EnableFunctionLevelLinking', {
-      map: {'true': '/Gy', 'false': '/Gy-'} })
-    cl('MinimalRebuild', { map: {'true': '/Gm'} })
-    cl('BufferSecurityCheck', { map: {'true': '/GS', 'false': '/GS-'} })
+      map: {'true': '/Gy', 'false': '/Gy-'} });
+    cl('MinimalRebuild', { map: {'true': '/Gm'} });
+    cl('BufferSecurityCheck', { map: {'true': '/GS', 'false': '/GS-'} });
     cl('BasicRuntimeChecks', {
-      map: {'1': 's', '2': 'u', '3': '1'}, prefix: '/RTC' })
+      map: {'1': 's', '2': 'u', '3': '1'}, prefix: '/RTC' });
     cl('RuntimeLibrary', {
-      map: {'0': 'T', '1': 'Td', '2': 'D', '3': 'Dd'}, prefix: '/M' })
-    cl('ExceptionHandling', { map: {'1': 'sc','2': 'a'}, prefix: '/EH' })
-    cl('DefaultCharIsUnsigned', { map: {'true': '/J'} })
+      map: {'0': 'T', '1': 'Td', '2': 'D', '3': 'Dd'}, prefix: '/M' });
+    cl('ExceptionHandling', { map: {'1': 'sc','2': 'a'}, prefix: '/EH' });
+    cl('DefaultCharIsUnsigned', { map: {'true': '/J'} });
     cl('TreatWChar_tAsBuiltInType', {
-      map: {'false': '-', 'true': ''}, prefix: '/Zc:wchar_t' })
-    cl('EnablePREfast', { map: {'true': '/analyze'} })
-    cl('AdditionalOptions')
+      map: {'false': '-', 'true': ''}, prefix: '/Zc:wchar_t' });
+    cl('EnablePREfast', { map: {'true': '/analyze'} });
+    cl('AdditionalOptions');
     cl('EnableEnhancedInstructionSet', {
       map: {'1': 'SSE', '2': 'SSE2', '3': 'AVX', '4': 'IA32', '5': 'AVX2'},
-      prefix: '/arch:' })
+      prefix: '/arch:' });
     cl('ForcedIncludeFiles', { prefix: '/FI'});
     // New flag required in 2013 to maintain previous PDB behavior.
-    if (true) //TODO: (vs_version.short_name in ('2013', '2013e', '2015'))
-      cflags.push('/FS');
+    //TODO: if (vs_version.short_name in ('2013', '2013e', '2015'))
+    cflags.push('/FS');
     // ninja handles parallelism by itself, don't have the compiler do it too.
     cflags = cflags.filter(f => !f.startsWith('/MP'));
   }
@@ -159,30 +157,30 @@ function compilerFlags(compiler) {
 }
 
 function librarianFlags(librarian) {
-    let libflags = []
-    if (librarian) {
-      let lib = SettingsWrapper(librarian, libflags);
+  let libflags = [];
+  if (librarian) {
+    let lib = settingsWrapper(librarian, libflags);
       //TODO: libflags = libflags.concat(GetAdditionalLibraryDirectories(
       //       librarian, config, gyp_to_build_path));
-      lib('LinkTimeCodeGeneration', { map: {'true': '/LTCG'} });
-      lib('TargetMachine', {
-        map: {'1': 'X86', '17': 'X64', '3': 'ARM'}, prefix: '/MACHINE:' });
-      lib('OutputFile', { prefix: '/OUT:', map: expandMSBuildMacros });
-      lib('AdditionalOptions');
-    }
-    return libflags;
+    lib('LinkTimeCodeGeneration', { map: {'true': '/LTCG'} });
+    lib('TargetMachine', {
+      map: {'1': 'X86', '17': 'X64', '3': 'ARM'}, prefix: '/MACHINE:' });
+    lib('OutputFile', { prefix: '/OUT:', map: expandMSBuildMacros });
+    lib('AdditionalOptions');
+  }
+  return libflags;
 }
 
 function linkerFlags(linker) {
   let ldflags = [];
   if (linker) {
-    let ld = SettingsWrapper(linker, ldflags);
+    let ld = settingsWrapper(linker, ldflags);
     ld('GenerateDebugInformation', { map: {'true': '/DEBUG'} });
     ld('TargetMachine', {
       map: {'1': 'X86', '17': 'X64', '3': 'ARM'}, prefix: '/MACHINE:' });
     //TODO: ldflags = ldflags.concat(GetAdditionalLibraryDirectories(
     //        linker, config, gyp_to_build_path));
-    ld('DelayLoadDLLs', { prefix: '/DELAYLOAD:' })
+    ld('DelayLoadDLLs', { prefix: '/DELAYLOAD:' });
     ld('TreatLinkerWarningAsErrors', {
       map: {'true': '', 'false': ':NO'}, prefix: '/WX' });
     ld('OutputFile', { map: expandMSBuildMacros, prefix: '/OUT:' });
@@ -240,13 +238,16 @@ function linkerFlags(linker) {
     ld('AdditionalDependencies');
     ld('ImageHasSafeExceptionHandlers', {
       map: {'false': ':NO', 'true': ''},
-      prefix: '/SAFESEH', 
-      /*TODO: defvalue: GetArch(config) === 'x86'? 'true' : undefined*/ });
+      prefix: '/SAFESEH'
+      /*TODO: defvalue: GetArch(config) === 'x86'? 'true' : undefined*/
+    });
 
     // If the base address is not specifically controlled,
     // DYNAMICBASE should be on by default.
-    if (!ldflags.find(f => f.startsWith('/DYNAMICBASE')
-      || f.startsWith('/FIXED'))) ldflags.push('/DYNAMICBASE');
+    if (!ldflags.find(f => f.startsWith('/DYNAMICBASE') ||
+                           f.startsWith('/FIXED'))) {
+      ldflags.push('/DYNAMICBASE');
+    }
 
     // If the NXCOMPAT flag has not been specified, default to on. Despite the
     // documentation that says this only defaults to on when the subsystem is
@@ -276,7 +277,7 @@ win.targetFlags = function targetFlags(target) {
   let ldflags = [];
 
   cflags = cflags.concat(compilerFlags(settings.VCCLCompilerTool));
-  cflags = cflags.concat(disabled_warnings.map(w => '/wd' + w))
+  cflags = cflags.concat(disabled_warnings.map(w => '/wd' + w));
 
   if (target.type === 'static_library') {
     ldflags = ldflags.concat(librarianFlags(settings.VCLibrarianTool));
@@ -314,7 +315,7 @@ win.escapeDefine = function escapeDefine(arg) {
   // passed literally through escaping so they can be singled to just the
   // original %. Otherwise, trying to pass the literal representation that
   // looks like an environment variable to the shell (e.g. %PATH%) would fail.
-  arg = arg.replace(/%/g, '%%')
+  arg = arg.replace(/%/g, '%%');
 
   // These commands are used in rsp files, so no escaping for the shell (via ^)
   // is necessary.
diff --git a/lib/gyp/py.js b/lib/gyp/py.js
index 5788689..dd99ec3 100644
--- a/lib/gyp/py.js
+++ b/lib/gyp/py.js
@@ -151,7 +151,7 @@ GYPJSON.prototype.parseString = function parseString() {
       }
     } else if (c === q) {
       break;
-    } else if (c === '\r' || c == '\n') {
+    } else if (c === '\r' || c === '\n') {
       throw new Error(`Unexpected newline in a string at ${this.pos()}`);
     } else {
       res += c;
@@ -256,7 +256,7 @@ function parseJSON(contents) {
   const g = new GYPJSON(contents);
   return g.parse(contents);
 }
-exports.parseJSON = parseJSON
+exports.parseJSON = parseJSON;
 
 function checkedParseJSON(contents) {
   /* Return the eval of a gyp file.
@@ -277,12 +277,12 @@ const MAX_PRIORITY = 4;
 // NOTE: This is only a small subset, but should be enough
 // TODO(indutny): consider expanding this, if needed
 const PRIORITY_RE = new RegExp(
-    `^(?:` +
-    `((?:not\\s+in|in|is not|is)(?=\\s|$)|==|!=|>=|<=|>|<)|` +  // priority 1
-    `(not)|` +  // priority 2, XXX(indutny): it is a prefix!!!
-    `(and)|` +  // priority 3
-    `(or)` +  // priority 4
-    `)`);
+    '^(?:' +
+    '((?:not\\s+in|in|is not|is)(?=\\s|$)|==|!=|>=|<=|>|<)|' +  // priority 1
+    '(not)|' +  // priority 2, XXX(indutny): it is a prefix!!!
+    '(and)|' +  // priority 3
+    '(or)' +  // priority 4
+    ')');
 
 function Condition(str) {
   GYPJSON.call(this, str);
@@ -300,7 +300,7 @@ Condition.prototype.parseOne = function parseOne(priority) {
     this.space();
 
     // .split()
-    if (this.peek() == '.') {
+    if (this.peek() === '.') {
       seed = this.parseMethod(seed);
       this.space();
     }
diff --git a/lib/gyp/shlex.js b/lib/gyp/shlex.js
index 0c1a48a..192e899 100644
--- a/lib/gyp/shlex.js
+++ b/lib/gyp/shlex.js
@@ -28,7 +28,7 @@ shlex.split = function split(str) {
         quotes = false;
       else
         quotes = c;
-    } else if (c === '\\' && quotes != '\'') {
+    } else if (c === '\\' && quotes !== '\'') {
       if (i + 1 >= str.length)
         throw new Error('Unmatched escape');
       acc += str.slice(off, i);
diff --git a/package.json b/package.json
index c135316..3e116e7 100644
--- a/package.json
+++ b/package.json
@@ -7,12 +7,16 @@
   },
   "main": "lib/gyp.js",
   "scripts": {
-    "test": "mocha --reporter=spec test/*-test.js"
+    "lint": "make lint",
+    "format": "make format",
+    "test": "mocha --reporter=spec test/*-test.js && npm run lint"
   },
   "keywords": [],
   "author": "Fedor Indutny <fedor@indutny.com>",
   "license": "MIT",
   "devDependencies": {
+    "eslint": "^2.12.0",
+    "jshint": "^2.9.2",
     "mocha": "^2.5.3"
   },
   "dependencies": {
diff --git a/test/generator-ninja-writer-test.js b/test/generator-ninja-writer-test.js
index 85cd349..b039385 100644
--- a/test/generator-ninja-writer-test.js
+++ b/test/generator-ninja-writer-test.js
@@ -1,4 +1,5 @@
 'use strict';
+/* global describe it */
 
 const assert = require('assert');
 
diff --git a/test/platform-win-test.js b/test/platform-win-test.js
index 05c7c0a..c211d47 100644
--- a/test/platform-win-test.js
+++ b/test/platform-win-test.js
@@ -1,4 +1,5 @@
 'use strict';
+/* global describe it */
 
 const assert = require('assert');
 
@@ -12,27 +13,27 @@ describe('gyp.platform.win', () => {
 
     it('should remove prefix `-l`', () => {
       assert.deepEqual(
-        win.adjustLibraries(['-llib1.lib', 'lib2.lib']),
-        ['lib1.lib', 'lib2.lib']);
+        win.adjustLibraries([ '-llib1.lib', 'lib2.lib' ]),
+        [ 'lib1.lib', 'lib2.lib' ]);
     });
 
     it('should append suffix `.lib`', () => {
       assert.deepEqual(
-        win.adjustLibraries(['-llib1', 'lib2.lib', 'lib3.Lib']),
-        ['lib1.lib', 'lib2.lib', 'lib3.Lib']);
+        win.adjustLibraries([ '-llib1', 'lib2.lib', 'lib3.Lib' ]),
+        [ 'lib1.lib', 'lib2.lib', 'lib3.Lib' ]);
     });
 
     it('should remove prefix `-l` and append suffix `.lib`', () => {
       assert.deepEqual(
-        win.adjustLibraries(['lib1', '-llib2', '-llib3.lib', 'lib4.lib']),
-        ['lib1.lib', 'lib2.lib', 'lib3.lib', 'lib4.lib']);
+        win.adjustLibraries([ 'lib1', '-llib2', '-llib3.lib', 'lib4.lib' ]),
+        [ 'lib1.lib', 'lib2.lib', 'lib3.lib', 'lib4.lib' ]);
     });
 
     it('should preserve quotes', () => {
       assert.deepEqual(
-        win.adjustLibraries(['"some path/lib1"', '-l"lib2"', 
-                             '-l"lib3.lib"', '"lib4.lib"']),
-        ['"some path/lib1.lib"', '"lib2.lib"', '"lib3.lib"', '"lib4.lib"']);
+        win.adjustLibraries([ '"some path/lib1"', '-l"lib2"', 
+                             '-l"lib3.lib"', '"lib4.lib"' ]),
+        [ '"some path/lib1.lib"', '"lib2.lib"', '"lib3.lib"', '"lib4.lib"' ]);
     });
   });
 
@@ -40,10 +41,10 @@ describe('gyp.platform.win', () => {
     it('disable specific warnings', () => {
       const warnings = [1, 2, 3, 4];
       assert.deepEqual(win.targetFlags(
-        { msvs_disabled_warnings: []}).cflags, []);
+        { msvs_disabled_warnings: [] }).cflags, []);
       assert.deepEqual(win.targetFlags(
-        { msvs_disabled_warnings: warnings}).cflags,
-        ['/wd1', '/wd2', '/wd3', '/wd4']);
+        { msvs_disabled_warnings: warnings }).cflags,
+        [ '/wd1', '/wd2', '/wd3', '/wd4' ]);
     });
 
     it('compiler', () => {
@@ -72,9 +73,9 @@ describe('gyp.platform.win', () => {
         DefaultCharIsUnsigned: true,
         TreatWChar_tAsBuiltInType: true,
         EnablePREfast: true,
-        AdditionalOptions: ['/XXX', '/YYY', '/MP'], // /MP should be removed
+        AdditionalOptions: [ '/XXX', '/YYY', '/MP' ], // /MP should be removed
         EnableEnhancedInstructionSet: 5,
-        ForcedIncludeFiles: ['file1.h', 'file2.h'],
+        ForcedIncludeFiles: [ 'file1.h', 'file2.h' ]
       };
       const cflags = [
         '/Od',
@@ -115,7 +116,7 @@ describe('gyp.platform.win', () => {
         LinkTimeCodeGeneration: true,
         TargetMachine: 1,
         OutputFile: 'output.lib',
-        AdditionalOptions: ['/XXX', '/YYY']
+        AdditionalOptions: [ '/XXX', '/YYY' ]
       };
       const libflags = [
         '/LTCG',
@@ -131,16 +132,15 @@ describe('gyp.platform.win', () => {
       const linker = {
         GenerateDebugInformation: true,
         TargetMachine: 17,
-        DelayLoadDLLs: ['lib1.dll', 'lib2.dll'],
+        DelayLoadDLLs: [ 'lib1.dll', 'lib2.dll' ],
         TreatLinkerWarningAsErrors: false,
         OutputFile: 'output.dll',
-        GenerateDebugInformation: true,
         ProgramDatabaseFile: 'data.pdb',
         ProfileGuidedDatabase: 'data.pgd',
         GenerateMapFile: true,
         MapFileName: 'data.map',
         MapExports: true,
-        AdditionalOptions: ['/XXX', '/YYY'],
+        AdditionalOptions: [ '/XXX', '/YYY' ],
         MinimumRequiredVersion: 7,
         SubSystem: 2,
         StackReserveSize: 100,
@@ -152,16 +152,16 @@ describe('gyp.platform.win', () => {
         RandomizedBaseAddress: 1,
         DataExecutionPrevention: 2,
         OptimizeReferences: 2,
-        ForceSymbolReferences: ['aa', 'zz'],
+        ForceSymbolReferences: [ 'aa', 'zz' ],
         EnableCOMDATFolding: 2,
         LinkTimeCodeGeneration: 4,
-        IgnoreDefaultLibraryNames: ['xxx.lib'],
+        IgnoreDefaultLibraryNames: [ 'xxx.lib' ],
         ResourceOnlyDLL: true,
         EntryPointSymbol: 'main',
         Profile: true,
         LargeAddressAware: 2,
-        AdditionalDependencies: ['my1.lib', 'my2.lib'],
-        ImageHasSafeExceptionHandlers: true,
+        AdditionalDependencies: [ 'my1.lib', 'my2.lib' ],
+        ImageHasSafeExceptionHandlers: true
       };
       const ldflags = [
         '/DEBUG',
@@ -192,7 +192,7 @@ describe('gyp.platform.win', () => {
         '/PROFILE',
         '/LARGEADDRESSAWARE',
         'my1.lib', 'my2.lib',
-        '/SAFESEH',
+        '/SAFESEH'
       ];
       assert.deepEqual(win.targetFlags(
         { msvs_settings: { VCLinkerTool: linker }}).ldflags, ldflags);
diff --git a/test/py-base-test.js b/test/py-base-test.js
index d8b0bdc..5260b24 100644
--- a/test/py-base-test.js
+++ b/test/py-base-test.js
@@ -1,4 +1,5 @@
 'use strict';
+/* global describe it */
 
 const assert = require('assert');
 
@@ -6,7 +7,7 @@ const gyp = require('../');
 const Base = gyp.py.Base;
 
 describe('gyp.py.Base', () => {
-  describe('it should return proper pos', () => {
+  it('should return proper pos', () => {
     const b = new Base('123\n456\r\n987\r123');
     b.off = 11;
     assert.equal(b.pos(), '3:2');
diff --git a/test/py-compile-condition-test.js b/test/py-compile-condition-test.js
index 0ef02c1..e7d9b93 100644
--- a/test/py-compile-condition-test.js
+++ b/test/py-compile-condition-test.js
@@ -1,4 +1,5 @@
 'use strict';
+/* global describe it */
 
 const assert = require('assert');
 
diff --git a/test/py-json-test.js b/test/py-json-test.js
index e662391..acf10c2 100644
--- a/test/py-json-test.js
+++ b/test/py-json-test.js
@@ -1,4 +1,5 @@
 'use strict';
+/* global describe it */
 
 const assert = require('assert');
 
diff --git a/test/py-parse-condition-test.js b/test/py-parse-condition-test.js
index 96ce6b4..733f046 100644
--- a/test/py-parse-condition-test.js
+++ b/test/py-parse-condition-test.js
@@ -1,4 +1,5 @@
 'use strict';
+/* global describe it */
 
 const assert = require('assert');
 
diff --git a/test/shlex-test.js b/test/shlex-test.js
index f94a32d..6cb25de 100644
--- a/test/shlex-test.js
+++ b/test/shlex-test.js
@@ -1,4 +1,5 @@
 'use strict';
+/* global describe it */
 
 const assert = require('assert');
 
@@ -12,26 +13,26 @@ describe('gyp.shlex', () => {
 
   it('should coalesce parts in single quotes', () => {
     assert.deepEqual(shlex.split('a   pre\'b c\'post d'), [
-        'a', 'preb cpost', 'd' ]);
+      'a', 'preb cpost', 'd' ]);
   });
 
   it('should coalesce parts in double quotes', () => {
     assert.deepEqual(shlex.split('a   pre"b c"post d'), [
-        'a', 'preb cpost', 'd' ]);
+      'a', 'preb cpost', 'd' ]);
   });
 
   it('should not escape `\\` in single quotes', () => {
     assert.deepEqual(shlex.split('a   pre\'b\\n c\'post d'), [
-        'a', 'preb\\n cpost', 'd' ]);
+      'a', 'preb\\n cpost', 'd' ]);
   });
 
   it('should escape `\\` in double quotes', () => {
     assert.deepEqual(shlex.split('a   pre\"b\\n c\"post d'), [
-        'a', 'preb\n cpost', 'd' ]);
+      'a', 'preb\n cpost', 'd' ]);
   });
 
   it('should escape `\\"` in double quotes', () => {
     assert.deepEqual(shlex.split('a   pre\"b\\" c\"post d'), [
-        'a', 'preb" cpost', 'd' ]);
+      'a', 'preb" cpost', 'd' ]);
   });
 });