diff --git a/src/lib/plugins/index.js b/src/lib/plugins/index.js
deleted file mode 100644
index 0c28519706..0000000000
--- a/src/lib/plugins/index.js
+++ /dev/null
@@ -1,48 +0,0 @@
-module.exports = {
-  loadPlugin: loadPlugin,
-};
-
-function loadPlugin(packageManager, options) {
-  if (options && options.docker) {
-    return require('snyk-docker-plugin');
-  }
-  switch (packageManager) {
-    case 'npm': {
-      return require('./npm');
-    }
-    case 'rubygems': {
-      return require('./rubygems');
-    }
-    case 'maven': {
-      return require('snyk-mvn-plugin');
-    }
-    case 'gradle': {
-      return require('snyk-gradle-plugin');
-    }
-    case 'sbt': {
-      return require('snyk-sbt-plugin');
-    }
-    case 'yarn': {
-      return require('./yarn');
-    }
-    case 'pip': {
-      return require('snyk-python-plugin');
-    }
-    case 'golangdep':
-    case 'govendor': {
-      return require('snyk-go-plugin');
-    }
-    case 'nuget': {
-      return require('snyk-nuget-plugin');
-    }
-    case 'paket': {
-      return require('snyk-nuget-plugin');
-    }
-    case 'composer': {
-      return require('snyk-php-plugin');
-    }
-    default: {
-      throw new Error('Unsupported package manager: ' + packageManager);
-    }
-  }
-}
diff --git a/src/lib/plugins/index.ts b/src/lib/plugins/index.ts
new file mode 100644
index 0000000000..02d9b104de
--- /dev/null
+++ b/src/lib/plugins/index.ts
@@ -0,0 +1,76 @@
+import * as dockerPlugin from 'snyk-docker-plugin';
+import * as npmPlugin from './npm';
+import * as rubygemsPlugin from './rubygems';
+import * as mvnPlugin from 'snyk-mvn-plugin';
+import * as gradlePlugin from 'snyk-gradle-plugin';
+import * as sbtPlugin from 'snyk-sbt-plugin';
+import * as yarnPlugin from './yarn';
+import * as pythonPlugin from 'snyk-python-plugin';
+import * as goPlugin from 'snyk-go-plugin';
+import * as nugetPlugin from 'snyk-nuget-plugin';
+import * as phpPlugin from 'snyk-php-plugin';
+
+interface InspectResult {
+  plugin: {
+    name: string;
+    runtime: string;
+  };
+  package: any;
+}
+
+interface Options {
+  docker?: boolean;
+  traverseNodeModules?: boolean;
+  dev?: boolean;
+  strictOutOfSync?: boolean;
+}
+
+interface Plugin {
+  inspect: (root: string, targetFile: string, options?: Options) => Promise<InspectResult>;
+}
+
+export function loadPlugin(packageManager: string, options: Options = {}): Plugin {
+  if (options.docker) {
+    return dockerPlugin;
+  }
+
+  switch (packageManager) {
+    case 'npm': {
+      return npmPlugin;
+    }
+    case 'rubygems': {
+      return rubygemsPlugin;
+    }
+    case 'maven': {
+      return mvnPlugin;
+    }
+    case 'gradle': {
+      return gradlePlugin;
+    }
+    case 'sbt': {
+      return sbtPlugin;
+    }
+    case 'yarn': {
+      return yarnPlugin;
+    }
+    case 'pip': {
+      return pythonPlugin;
+    }
+    case 'golangdep':
+    case 'govendor': {
+      return goPlugin;
+    }
+    case 'nuget': {
+      return nugetPlugin;
+    }
+    case 'paket': {
+      return nugetPlugin;
+    }
+    case 'composer': {
+      return phpPlugin;
+    }
+    default: {
+      throw new Error(`Unsupported package manager: ${packageManager}`);
+    }
+  }
+}
diff --git a/src/lib/plugins/npm/index.js b/src/lib/plugins/npm/index.js
deleted file mode 100644
index 358084c8ea..0000000000
--- a/src/lib/plugins/npm/index.js
+++ /dev/null
@@ -1,70 +0,0 @@
-const snyk = require('../../');
-const fileSystem = require('fs');
-const fs = require('then-fs');
-const path = require('path');
-const lockFileParser = require('snyk-nodejs-lockfile-parser');
-const _ = require('lodash');
-
-module.exports = {
-  inspect,
-};
-
-function inspect(root, targetFile, options) {
-  const isLockFileBased = targetFile.endsWith('package-lock.json');
-
-  const isShrinkwrapPresent = fileSystem.existsSync(
-    path.resolve(root, targetFile).dir, 'npm-shrinkwrap.json'
-  );
-  if (isLockFileBased && !isShrinkwrapPresent && !options.traverseNodeModules) {
-    return generateDependenciesFromLockfile(root, options, targetFile)
-      .then((modules) => ({
-        plugin: {
-          name: 'snyk-nodejs-lockfile-parser',
-          runtime: process.version,
-        },
-        package: modules,
-      }));
-  }
-
-  // old style npm projects
-  return snyk.modules(root, Object.assign({}, options, {noFromArrays: true}))
-    .then(function (modules) {
-      return {
-        plugin: {
-          name: 'snyk-resolve-deps',
-          runtime: process.version,
-        },
-        package: modules,
-      };
-    });
-}
-
-async function generateDependenciesFromLockfile(root, options, targetFile) {
-  const lockFileFullPath = path.resolve(root, targetFile);
-  if (!fileSystem.existsSync(lockFileFullPath)) {
-    throw new Error('Lockfile ' + targetFile + ' not found at location: ' +
-    lockFileFullPath);
-  }
-
-  const fullPath = path.parse(lockFileFullPath);
-  const manifestFileFullPath = path.resolve(fullPath.dir, 'package.json');
-
-  if (!fileSystem.existsSync(manifestFileFullPath)) {
-    throw new Error('Manifest file package.json not found at location: ' +
-      manifestFileFullPath);
-  }
-
-  if (!manifestFileFullPath && lockFileFullPath) {
-    throw new Error('Detected a lockfile at location: '
-    + lockFileFullPath + '\n However the package.json is missing!');
-  }
-
-  const manifestFile = await fs.readFile(manifestFileFullPath, 'utf-8');
-  const lockFile = await fs.readFile(lockFileFullPath, 'utf-8');
-  const defaultManifestFileName = path.relative(root, manifestFileFullPath);
-
-  const strictOutOfSync = _.get(options, 'strictOutOfSync', true);
-  return lockFileParser.buildDepTree(manifestFile, lockFile, options.dev,
-    lockFileParser.LockfileType.npm, strictOutOfSync, defaultManifestFileName);
-}
-
diff --git a/src/lib/plugins/npm/index.ts b/src/lib/plugins/npm/index.ts
new file mode 100644
index 0000000000..19cb696e85
--- /dev/null
+++ b/src/lib/plugins/npm/index.ts
@@ -0,0 +1,80 @@
+import * as path from 'path';
+import * as fs from 'then-fs';
+import * as _ from 'lodash';
+import {buildDepTree, PkgTree, LockfileType} from 'snyk-nodejs-lockfile-parser';
+import * as snyk from '../../';
+
+interface Options {
+  traverseNodeModules?: boolean;
+  dev?: boolean;
+  strictOutOfSync?: boolean;
+}
+
+interface InspectResult {
+  plugin: {
+    name: string;
+    runtime: string;
+  };
+  package: PkgTree;
+}
+
+export async function inspect(root: string, targetFile: string, options: Options = {}): Promise<InspectResult> {
+  const isLockFileBased = targetFile.endsWith('package-lock.json');
+  const targetFileFullPath = path.resolve(root, targetFile);
+  const isShrinkwrapPresent = await fs.exists(path.join(path.dirname(targetFileFullPath), 'npm-shrinkwrap.json'));
+
+  if (isLockFileBased && !isShrinkwrapPresent && !options.traverseNodeModules) {
+    return {
+      plugin: {
+        name: 'snyk-nodejs-lockfile-parser',
+        runtime: process.version,
+      },
+      package: await generateDependenciesFromLockfile(root, targetFile, options),
+    };
+  }
+
+  // Old style npm projects.
+  return {
+    plugin: {
+      name: 'snyk-resolve-deps',
+      runtime: process.version,
+    },
+    package: await snyk.modules(root, Object.assign({}, options, {noFromArrays: true})),
+  };
+}
+
+async function generateDependenciesFromLockfile(root: string, targetFile: string, options: Options): Promise<PkgTree> {
+  const lockFileFullPath = path.resolve(root, targetFile);
+
+  if (!await fs.exists(lockFileFullPath)) {
+    throw new Error(`Lockfile ${targetFile} not found at location: ${lockFileFullPath}`);
+  }
+
+  const fullPath = path.parse(lockFileFullPath);
+  const manifestFileFullPath = path.resolve(fullPath.dir, 'package.json');
+
+  if (!await fs.exists(manifestFileFullPath)) {
+    throw new Error(`Manifest file package.json not found at location: ${manifestFileFullPath}`);
+  }
+
+  if (!manifestFileFullPath && lockFileFullPath) {
+    throw new Error(`Detected a lockfile at location: ${lockFileFullPath}\nHowever the package.json is missing!`);
+  }
+
+  const [manifestFile, lockFile] = await Promise.all([
+    await fs.readFile(manifestFileFullPath, 'utf-8'),
+    await fs.readFile(lockFileFullPath, 'utf-8'),
+  ]);
+
+  const defaultManifestFileName = path.relative(root, manifestFileFullPath);
+  const strictOutOfSync = _.get(options, 'strictOutOfSync', true);
+
+  return await buildDepTree(
+    manifestFile,
+    lockFile,
+    options.dev,
+    LockfileType.npm,
+    strictOutOfSync,
+    defaultManifestFileName,
+  );
+}
diff --git a/src/lib/plugins/rubygems/index.js b/src/lib/plugins/rubygems/index.js
deleted file mode 100644
index 4af4fc2c1a..0000000000
--- a/src/lib/plugins/rubygems/index.js
+++ /dev/null
@@ -1,33 +0,0 @@
-var repoInspectors = require('./inspectors');
-
-module.exports = {
-  inspect: inspect,
-};
-
-function inspect(root, targetFile) {
-  return gatherSpecs(root, targetFile)
-    .then(function (specs) {
-      var pkg = {
-        name: specs.packageName,
-        targetFile: specs.targetFile,
-        files: specs.files,
-      };
-      return {
-        plugin: {
-          name: 'bundled:rubygems',
-          runtime: 'unknown',
-        },
-        package: pkg,
-      };
-    });
-}
-
-function gatherSpecs(root, targetFile) {
-  for (var i = repoInspectors.length - 1; i >= 0; i--) {
-    var inspector = repoInspectors[i];
-    if (inspector.canHandle(targetFile)) {
-      return inspector.gatherSpecs(root, targetFile);
-    }
-  }
-  throw new Error('Could not handle file: ' + targetFile);
-}
diff --git a/src/lib/plugins/rubygems/index.ts b/src/lib/plugins/rubygems/index.ts
new file mode 100644
index 0000000000..0beec03e87
--- /dev/null
+++ b/src/lib/plugins/rubygems/index.ts
@@ -0,0 +1,39 @@
+import {inspectors, Spec} from './inspectors';
+
+interface InspectResult {
+  plugin: {
+    name: string;
+    runtime: string;
+  };
+  package: {
+    name: string;
+    targetFile: string;
+    files: any
+  };
+}
+
+export async function inspect(root: string, targetFile: string): Promise<InspectResult> {
+  const specs = await gatherSpecs(root, targetFile);
+
+  return {
+    plugin: {
+      name: 'bundled:rubygems',
+      runtime: 'unknown',
+    },
+    package: {
+      name: specs.packageName,
+      targetFile: specs.targetFile,
+      files: specs.files,
+    },
+  };
+}
+
+async function gatherSpecs(root, targetFile): Promise<Spec> {
+  for (const inspector of inspectors) {
+    if (inspector.canHandle(targetFile)) {
+      return await inspector.gatherSpecs(root, targetFile);
+    }
+  }
+
+  throw new Error(`Could not handle file: ${targetFile}`);
+}
diff --git a/src/lib/plugins/rubygems/inspectors/gemfile.js b/src/lib/plugins/rubygems/inspectors/gemfile.js
deleted file mode 100644
index 5e1ee8c64b..0000000000
--- a/src/lib/plugins/rubygems/inspectors/gemfile.js
+++ /dev/null
@@ -1,34 +0,0 @@
-var path = require('path');
-var tryGetSpec = require('./try-get-spec');
-var pattern = /^Gemfile(\.lock)*$/;
-
-module.exports = {
-  canHandle: function handles(file) {
-    return file && pattern.test(path.basename(file));
-  },
-
-  gatherSpecs: function gatherSpecs(root, target) {
-    var targetName = path.basename(target);
-    var targetDir = path.dirname(target);
-    var files = {};
-
-    var gemfileLock = tryGetSpec(root, path.join(targetDir, 'Gemfile.lock'));
-    if (gemfileLock) {
-      files.gemfileLock = gemfileLock;
-    } else {
-      throw new Error('Missing Gemfile.lock file: we can\'t test ' +
-      'without dependencies.\nPlease run `bundle install` first.');
-    }
-
-    var gemfile = tryGetSpec(root, path.join(targetDir, 'Gemfile'));
-    if (gemfile) {
-      files.gemfile = gemfile;
-    }
-
-    return Promise.resolve({
-      packageName: path.basename(root),
-      targetFile: path.join(targetDir, targetName),
-      files: files,
-    });
-  },
-};
diff --git a/src/lib/plugins/rubygems/inspectors/gemfile.ts b/src/lib/plugins/rubygems/inspectors/gemfile.ts
new file mode 100644
index 0000000000..dedc592260
--- /dev/null
+++ b/src/lib/plugins/rubygems/inspectors/gemfile.ts
@@ -0,0 +1,36 @@
+import * as path from 'path';
+import {Files, tryGetSpec} from './try-get-spec';
+import {Spec} from './index';
+
+const pattern = /^Gemfile(\.lock)*$/;
+
+export function canHandle(file: string): boolean {
+  return !!file && pattern.test(path.basename(file));
+}
+
+export async function gatherSpecs(root: string, target: string): Promise<Spec> {
+  const targetName = path.basename(target);
+  const targetDir = path.dirname(target);
+  const files: Files = {};
+
+  const gemfileLock = await tryGetSpec(root, path.join(targetDir, 'Gemfile.lock'));
+
+  if (gemfileLock) {
+    files.gemfileLock = gemfileLock;
+  } else {
+    throw new Error('Missing Gemfile.lock file: we can\'t test ' +
+      'without dependencies.\nPlease run `bundle install` first.');
+  }
+
+  const gemfile = await tryGetSpec(root, path.join(targetDir, 'Gemfile'));
+
+  if (gemfile) {
+    files.gemfile = gemfile;
+  }
+
+  return {
+    packageName: path.basename(root),
+    targetFile: path.join(targetDir, targetName),
+    files,
+  };
+}
diff --git a/src/lib/plugins/rubygems/inspectors/gemspec.js b/src/lib/plugins/rubygems/inspectors/gemspec.js
deleted file mode 100644
index 303c1bb7fd..0000000000
--- a/src/lib/plugins/rubygems/inspectors/gemspec.js
+++ /dev/null
@@ -1,38 +0,0 @@
-var path = require('path');
-var tryGetSpec = require('./try-get-spec');
-var pattern = /\.gemspec$/;
-
-module.exports = {
-  canHandle: function handles(file) {
-    return file && pattern.test(file);
-  },
-
-  gatherSpecs: function gatherSpecs(root, target) {
-    var targetName = path.basename(target);
-    var targetDir = path.dirname(target);
-    var files = {};
-
-    var gemspec = tryGetSpec(root, path.join(targetDir, targetName));
-    if (gemspec) {
-      files.gemspec = gemspec;
-    } else {
-      throw 'File not found: ' + target;
-    }
-
-    var gemfileLock = tryGetSpec(root, path.join(targetDir, 'Gemfile.lock'));
-    if (gemfileLock) {
-      files.gemfileLock = gemfileLock;
-    }
-
-    var gemfile = tryGetSpec(root, path.join(targetDir, 'Gemfile'));
-    if (gemfile) {
-      files.gemfile = gemfile;
-    }
-
-    return Promise.resolve({
-      packageName: path.basename(root),
-      targetFile: path.join(targetDir, targetName),
-      files: files,
-    });
-  },
-};
diff --git a/src/lib/plugins/rubygems/inspectors/gemspec.ts b/src/lib/plugins/rubygems/inspectors/gemspec.ts
new file mode 100644
index 0000000000..cb20d61d91
--- /dev/null
+++ b/src/lib/plugins/rubygems/inspectors/gemspec.ts
@@ -0,0 +1,41 @@
+import * as path from 'path';
+import {Files, tryGetSpec} from './try-get-spec';
+import {Spec} from './index';
+
+const pattern = /\.gemspec$/;
+
+export function canHandle(file: string): boolean {
+  return !!file && pattern.test(file);
+}
+
+export async function gatherSpecs(root: string, target: string): Promise<Spec> {
+  const targetName = path.basename(target);
+  const targetDir = path.dirname(target);
+  const files: Files = {};
+
+  const gemspec = await tryGetSpec(root, path.join(targetDir, targetName));
+
+  if (gemspec) {
+    files.gemspec = gemspec;
+  } else {
+    throw new Error(`File not found: ${target}`);
+  }
+
+  const gemfileLock = await tryGetSpec(root, path.join(targetDir, 'Gemfile.lock'));
+
+  if (gemfileLock) {
+    files.gemfileLock = gemfileLock;
+  }
+
+  const gemfile = await tryGetSpec(root, path.join(targetDir, 'Gemfile'));
+
+  if (gemfile) {
+    files.gemfile = gemfile;
+  }
+
+  return {
+    packageName: path.basename(root),
+    targetFile: path.join(targetDir, targetName),
+    files,
+  };
+}
diff --git a/src/lib/plugins/rubygems/inspectors/index.js b/src/lib/plugins/rubygems/inspectors/index.js
deleted file mode 100644
index ed3535db0b..0000000000
--- a/src/lib/plugins/rubygems/inspectors/index.js
+++ /dev/null
@@ -1,4 +0,0 @@
-module.exports = [
-  require('./gemspec'),
-  require('./gemfile'),
-];
diff --git a/src/lib/plugins/rubygems/inspectors/index.ts b/src/lib/plugins/rubygems/inspectors/index.ts
new file mode 100644
index 0000000000..212e19645c
--- /dev/null
+++ b/src/lib/plugins/rubygems/inspectors/index.ts
@@ -0,0 +1,14 @@
+import * as gemfile from './gemfile';
+import * as gemspec from './gemspec';
+import {Files} from './try-get-spec';
+
+export interface Spec {
+  packageName: string;
+  targetFile: string;
+  files: Files;
+}
+
+export const inspectors = [
+  gemfile,
+  gemspec,
+];
diff --git a/src/lib/plugins/rubygems/inspectors/try-get-spec.js b/src/lib/plugins/rubygems/inspectors/try-get-spec.js
deleted file mode 100644
index 6b842b67c8..0000000000
--- a/src/lib/plugins/rubygems/inspectors/try-get-spec.js
+++ /dev/null
@@ -1,13 +0,0 @@
-var fs = require('then-fs');
-var path = require('path');
-
-module.exports = function tryGetSpec(dir, name) {
-  var file = path.resolve(dir, name);
-  if (fs.existsSync(file)) {
-    return {
-      name: name,
-      contents: new Buffer(fs.readFileSync(file)).toString('base64'),
-    };
-  }
-  return null;
-};
diff --git a/src/lib/plugins/rubygems/inspectors/try-get-spec.ts b/src/lib/plugins/rubygems/inspectors/try-get-spec.ts
new file mode 100644
index 0000000000..c4c3c35dd5
--- /dev/null
+++ b/src/lib/plugins/rubygems/inspectors/try-get-spec.ts
@@ -0,0 +1,25 @@
+import * as path from 'path';
+import * as fs from 'then-fs';
+
+interface File {
+  name: string;
+  contents: string;
+}
+
+export interface Files {
+  gemfileLock?: File;
+  gemfile?: File;
+  gemspec?: File;
+}
+
+export async function tryGetSpec(dir: string, name: string): Promise<File | null> {
+  const filePath = path.resolve(dir, name);
+
+  if (await fs.exists(filePath)) {
+    return {
+      name,
+      contents: new Buffer(await fs.readFile(filePath)).toString('base64'),
+    };
+  }
+  return null;
+}
diff --git a/src/lib/plugins/yarn/index.js b/src/lib/plugins/yarn/index.js
deleted file mode 100644
index 7e3853af01..0000000000
--- a/src/lib/plugins/yarn/index.js
+++ /dev/null
@@ -1,87 +0,0 @@
-const snyk = require('../../');
-const fileSystem = require('fs');
-const fs = require('then-fs');
-const path = require('path');
-const lockFileParser = require('snyk-nodejs-lockfile-parser');
-const debug = require('debug')('snyk');
-const _ = require('lodash');
-
-module.exports = {
-  inspect,
-};
-
-async function inspect(root, targetFile, options) {
-  const isLockFileBased = targetFile.endsWith('yarn.lock');
-
-  const isShrinkwrapPresent = fileSystem.existsSync(
-    path.resolve(root, targetFile).dir, 'npm-shrinkwrap.json'
-  );
-
-  if (getRuntimeVersion() < 6) {
-    options.traverseNodeModules = true;
-
-    debug('Falling back to node_modules traversal for yarn.lock projects on Node < 6');
-    const isNodeModulesFolderPresent = await fs.exists(path.join(root, 'node_modules'));
-    if (!isNodeModulesFolderPresent) {
-      // throw a custom error
-      throw new Error('Missing node_modules folder: we can\'t test ' +
-        'without dependencies.\nPlease run \'yarn install\' first.');
-    }
-  }
-
-  if (isLockFileBased && !isShrinkwrapPresent && !options.traverseNodeModules) {
-    return generateDependenciesFromLockfile(root, options, targetFile)
-      .then((modules) => ({
-        plugin: {
-          name: 'snyk-nodejs-lockfile-parser',
-          runtime: process.version,
-        },
-        package: modules,
-      }));
-  }
-
-  // traverse node modules
-  return snyk.modules(root, Object.assign({}, options, {noFromArrays: true}))
-    .then(function (modules) {
-      return {
-        plugin: {
-          name: 'snyk-resolve-deps',
-          runtime: process.version,
-        },
-        package: modules,
-      };
-    });
-}
-
-async function generateDependenciesFromLockfile(root, options, targetFile) {
-  const lockFileFullPath = path.resolve(root, targetFile);
-  if (!fileSystem.existsSync(lockFileFullPath)) {
-    throw new Error('Lockfile ' + targetFile + ' not found at location: ' +
-    lockFileFullPath);
-  }
-
-  const fullPath = path.parse(lockFileFullPath);
-  const manifestFileFullPath = path.resolve(fullPath.dir, 'package.json');
-
-  if (!fileSystem.existsSync(manifestFileFullPath)) {
-    throw new Error('Manifest file yarn.lock not found at location: ' +
-      manifestFileFullPath);
-  }
-
-  if (!manifestFileFullPath && lockFileFullPath) {
-    throw new Error('Detected a lockfile at location: '
-    + lockFileFullPath + '\n However the yarn.lock is missing!');
-  }
-
-  const manifestFile = await fs.readFile(manifestFileFullPath, 'utf-8');
-  const lockFile = await fs.readFile(lockFileFullPath, 'utf-8');
-  const defaultManifestFileName = path.relative(root, manifestFileFullPath);
-
-  const strictOutOfSync = _.get(options, 'strictOutOfSync', true);
-  return lockFileParser.buildDepTree(manifestFile, lockFile, options.dev,
-    lockFileParser.LockfileType.yarn, strictOutOfSync, defaultManifestFileName);
-}
-
-function getRuntimeVersion() {
-  return parseInt(process.version.slice(1).split('.')[0], 10);
-}
diff --git a/src/lib/plugins/yarn/index.ts b/src/lib/plugins/yarn/index.ts
new file mode 100644
index 0000000000..58f0505791
--- /dev/null
+++ b/src/lib/plugins/yarn/index.ts
@@ -0,0 +1,98 @@
+import * as path from 'path';
+import * as fs from 'then-fs';
+import * as _ from 'lodash';
+import * as Debug from 'debug';
+import {buildDepTree, PkgTree, LockfileType} from 'snyk-nodejs-lockfile-parser';
+import * as snyk from '../../';
+
+const debug = Debug('snyk');
+
+interface Options {
+  traverseNodeModules?: boolean;
+  dev?: boolean;
+  strictOutOfSync?: boolean;
+}
+
+interface InspectResult {
+  plugin: {
+    name: string;
+    runtime: string;
+  };
+  package: PkgTree;
+}
+
+export async function inspect(root, targetFile, options: Options = {}): Promise<InspectResult> {
+  const isLockFileBased = targetFile.endsWith('yarn.lock');
+  const targetFileFullPath = path.resolve(root, targetFile);
+  const isShrinkwrapPresent = await fs.exists(path.join(path.dirname(targetFileFullPath), 'npm-shrinkwrap.json'));
+
+  if (getRuntimeVersion() < 6) {
+    options.traverseNodeModules = true;
+
+    debug('Falling back to node_modules traversal for yarn.lock projects on Node < 6');
+    const isNodeModulesFolderPresent = await fs.exists(path.join(root, 'node_modules'));
+    if (!isNodeModulesFolderPresent) {
+      // throw a custom error
+      throw new Error('Missing node_modules folder: we can\'t test ' +
+        'without dependencies.\nPlease run \'yarn install\' first.');
+    }
+  }
+
+  if (isLockFileBased && !isShrinkwrapPresent && !options.traverseNodeModules) {
+    return {
+      plugin: {
+        name: 'snyk-nodejs-lockfile-parser',
+        runtime: process.version,
+      },
+      package: await generateDependenciesFromLockfile(root, options, targetFile),
+    };
+  }
+
+  // Traverse node modules.
+  return {
+    plugin: {
+      name: 'snyk-resolve-deps',
+      runtime: process.version,
+    },
+    package: await snyk.modules(root, Object.assign({}, options, {noFromArrays: true})),
+  };
+}
+
+function getRuntimeVersion(): number {
+  return parseInt(process.version.slice(1).split('.')[0], 10);
+}
+
+async function generateDependenciesFromLockfile(root, options, targetFile): Promise<PkgTree> {
+  const lockFileFullPath = path.resolve(root, targetFile);
+  if (!await fs.exists(lockFileFullPath)) {
+    throw new Error(`Lockfile ${targetFile} not found at location: ${lockFileFullPath}`);
+  }
+
+  const fullPath = path.parse(lockFileFullPath);
+  const manifestFileFullPath = path.resolve(fullPath.dir, 'package.json');
+
+  if (!await fs.exists(manifestFileFullPath)) {
+    throw new Error(`Manifest file yarn.lock not found at location: ${manifestFileFullPath}`);
+  }
+
+  if (!manifestFileFullPath && lockFileFullPath) {
+    throw new Error(`Detected a lockfile at location: ${lockFileFullPath}\nHowever the yarn.lock is missing!`);
+  }
+
+  const [manifestFile, lockFile] = await Promise.all([
+    await fs.readFile(manifestFileFullPath, 'utf-8'),
+    await fs.readFile(lockFileFullPath, 'utf-8'),
+  ]);
+
+  const defaultManifestFileName = path.relative(root, manifestFileFullPath);
+  const strictOutOfSync = _.get(options, 'strictOutOfSync', true);
+
+  return buildDepTree(
+    manifestFile,
+    lockFile,
+    options.dev,
+    LockfileType.yarn,
+    strictOutOfSync,
+    defaultManifestFileName,
+  );
+}
diff --git a/test/acceptance/cli.acceptance.test.ts b/test/acceptance/cli.acceptance.test.ts
index 3f136c29ff..24f36c1b6e 100644
--- a/test/acceptance/cli.acceptance.test.ts
+++ b/test/acceptance/cli.acceptance.test.ts
@@ -7,7 +7,6 @@ import * as _ from 'lodash';
 import * as cli from '../../src/cli/commands';
 import * as fakeServer from './fake-server';
 import * as subProcess from '../../src/lib/sub-process';
-import * as plugins from '../../src/lib/plugins';
 import * as needle from 'needle';
 
 // ensure this is required *after* the demo server, since this will
@@ -31,6 +30,9 @@ const server: any = fakeServer(process.env.SNYK_API, apiKey);
 const before = tap.runOnly ? only : test;
 const after = tap.runOnly ? only : test;
 
+// Should be after `process.env` setup.
+import * as plugins from '../../src/lib/plugins';
+
 // @later: remove this config stuff.
 // Was copied straight from ../src/cli-server.js
 before('setup', async (t) => {