diff --git a/index.js b/index.js
index 4f33c1d..f924ccf 100644
--- a/index.js
+++ b/index.js
@@ -60,7 +60,9 @@ function cleanEnv(inputEnv, specs = {}, options = {}) {
                                   ((devDefault !== undefined) && (devDefault === rawValue))
 
         try {
-            if (rawValue === undefined && !usingFalsyDefault) throw new EnvMissingError(spec.desc || '')
+            if (rawValue === undefined && !usingFalsyDefault) {
+                throw new EnvMissingError(spec.desc || '')
+            }
             output[k] = validateVar({ name: k, spec, rawValue })
         } catch (err) {
             if (options.reporter === null) throw err
@@ -90,4 +92,6 @@ function cleanEnv(inputEnv, specs = {}, options = {}) {
     return Object.freeze(output)
 }
 
-module.exports = { cleanEnv, makeValidator, bool, num, str, json, url, email, EnvError, EnvMissingError }
+module.exports = {
+    cleanEnv, makeValidator, bool, num, str, json, url, email, EnvError, EnvMissingError
+}
diff --git a/lib/validators.js b/lib/validators.js
index edf92e4..c015099 100644
--- a/lib/validators.js
+++ b/lib/validators.js
@@ -54,7 +54,7 @@ exports.num = makeValidator(input => {
 }, 'num')
 
 exports.str = makeValidator(input => {
-    if (typeof input === 'string') return input;
+    if (typeof input === 'string') return input
     throw new EnvError(`Not a string: "${input}"`)
 }, 'str')
 
@@ -65,7 +65,7 @@ exports.email = makeValidator(x => {
 
 exports.url = makeValidator(x => {
     const url = require('url')
-    let isValid;
+    let isValid = false
 
     if (url.URL) {
         try {
diff --git a/tests/test_basics.js b/tests/test_basics.js
index 3465718..1aeff92 100644
--- a/tests/test_basics.js
+++ b/tests/test_basics.js
@@ -17,11 +17,12 @@ test('strict option: only specified fields are passed through', () => {
 })
 
 test('transformer option: allow transformation of keys', () => {
+    const lowerCaseKey = (acc, [key, value]) => Object.assign(acc, { [key.toLowerCase()]: value })
     const opts = {
         transformer: i => Object
             .keys(i)
             .map(e => [e, i[e]])
-            .reduce((memo, [key, value]) => Object.assign({}, memo, { [key.toLowerCase()]: value }), {})
+            .reduce(lowerCaseKey, {})
     }
     const env = cleanEnv({ FOO: 'bar', FOO_BAR: 'baz' }, {
         FOO: str()
diff --git a/tests/test_dotenv.js b/tests/test_dotenv.js
index a027526..62bf311 100644
--- a/tests/test_dotenv.js
+++ b/tests/test_dotenv.js
@@ -1,6 +1,6 @@
 const fs = require('fs')
 const { createGroup, assert } = require('painless')
-const { cleanEnv, EnvError, str, num } = require('..')
+const { cleanEnv, str, num } = require('..')
 const test = createGroup()
 
 test.beforeEach(() => fs.writeFileSync('.env', `
diff --git a/tests/test_reporter.js b/tests/test_reporter.js
index 6744892..508e72d 100644
--- a/tests/test_reporter.js
+++ b/tests/test_reporter.js
@@ -9,7 +9,7 @@ test.beforeEach(() => {
     exitSpy = stub(process, 'exit', () => {})
 })
 test.afterEach(() => {
-    console.error.restore()
+    console.error.restore()     // eslint-disable-line no-console
     process.exit.restore()
 })