diff --git a/.gitignore b/.gitignore
index c1a17c9..a0d992f 100644
--- a/.gitignore
+++ b/.gitignore
@@ -10,3 +10,6 @@ package-lock.json
 
 # Code Editor directory
 .vscode
+
+# Ignore compiled dist/tests
+dist/test
diff --git a/dist/get-env-vars.js b/dist/get-env-vars.js
deleted file mode 100644
index 99f8a99..0000000
--- a/dist/get-env-vars.js
+++ /dev/null
@@ -1,66 +0,0 @@
-"use strict";
-Object.defineProperty(exports, "__esModule", { value: true });
-const parse_rc_file_1 = require("./parse-rc-file");
-const parse_env_file_1 = require("./parse-env-file");
-const RC_FILE_DEFAULT_LOCATIONS = ['./.env-cmdrc', './.env-cmdrc.js', './.env-cmdrc.json'];
-const ENV_FILE_DEFAULT_LOCATIONS = ['./.env', './.env.js', './.env.json'];
-function getEnvVars(options) {
-    return __awaiter(this, void 0, void 0, function* () {
-        options = options || {};
-        options.envFile = options.envFile || {};
-        // Check for rc file usage
-        if (options.rc) {
-            return getRCFile({ environments: options.rc.environments, filePath: options.rc.filePath });
-        }
-        return getEnvFile({ filePath: options.envFile.filePath, fallback: options.envFile.fallback });
-    });
-}
-exports.getEnvVars = getEnvVars;
-function getEnvFile({ filePath, fallback }) {
-    return __awaiter(this, void 0, void 0, function* () {
-        // Use env file
-        if (filePath) {
-            try {
-                return yield parse_env_file_1.getEnvFileVars(filePath);
-            }
-            catch (e) { }
-            if (!fallback) {
-                throw new Error(`Unable to locate env file at location (${filePath})`);
-            }
-        }
-        // Use the default env file locations
-        for (const path of ENV_FILE_DEFAULT_LOCATIONS) {
-            try {
-                return yield parse_env_file_1.getEnvFileVars(path);
-            }
-            catch (e) { }
-        }
-        throw new Error(`Unable to locate env file at default locations (${ENV_FILE_DEFAULT_LOCATIONS})`);
-    });
-}
-exports.getEnvFile = getEnvFile;
-async function getRCFile({ environments, filePath }) {
-    // User provided an .rc file path
-    if (filePath) {
-        try {
-            return await parse_rc_file_1.getRCFileVars({ environments, filePath });
-        }
-        catch (e) {
-            if (e.name !== 'PathError')
-                console.log(e);
-            throw new Error(`Unable to locate .rc file at location (${filePath})`);
-        }
-    }
-    // Use the default .rc file locations
-    for (const filePath of RC_FILE_DEFAULT_LOCATIONS) {
-        try {
-            return await parse_rc_file_1.getRCFileVars({ environments, filePath });
-        }
-        catch (e) {
-            if (e.name !== 'PathError')
-                console.log(e);
-        }
-    }
-    throw new Error(`Unable to locate .rc file at default locations (${RC_FILE_DEFAULT_LOCATIONS})`);
-}
-exports.getRCFile = getRCFile;
diff --git a/dist/env-cmd.d.ts b/dist/src/env-cmd.d.ts
similarity index 100%
rename from dist/env-cmd.d.ts
rename to dist/src/env-cmd.d.ts
diff --git a/dist/env-cmd.js b/dist/src/env-cmd.js
similarity index 96%
rename from dist/env-cmd.js
rename to dist/src/env-cmd.js
index 8a3f4bc..8f24b2e 100644
--- a/dist/env-cmd.js
+++ b/dist/src/env-cmd.js
@@ -31,11 +31,10 @@ exports.CLI = CLI;
  * @param {EnvCmdOptions} { command, commandArgs, envFile, rc, options }
  * @returns {Promise<{ [key: string]: any }>} Returns an object containing [environment variable name]: value
  */
-async function EnvCmd({ command, commandArgs, envFile, rc, options }) {
-    options = options || {};
+async function EnvCmd({ command, commandArgs, envFile, rc, options = {} }) {
     let env = await get_env_vars_1.getEnvVars({ envFile, rc });
     // Override the merge order if --no-override flag set
-    if (options.noOverride) {
+    if (options.noOverride === true) {
         env = Object.assign({}, env, process.env);
     }
     else {
diff --git a/dist/get-env-vars.d.ts b/dist/src/get-env-vars.d.ts
similarity index 100%
rename from dist/get-env-vars.d.ts
rename to dist/src/get-env-vars.d.ts
diff --git a/dist/src/get-env-vars.js b/dist/src/get-env-vars.js
new file mode 100644
index 0000000..3723f59
--- /dev/null
+++ b/dist/src/get-env-vars.js
@@ -0,0 +1,61 @@
+"use strict";
+Object.defineProperty(exports, "__esModule", { value: true });
+const parse_rc_file_1 = require("./parse-rc-file");
+const parse_env_file_1 = require("./parse-env-file");
+const RC_FILE_DEFAULT_LOCATIONS = ['./.env-cmdrc', './.env-cmdrc.js', './.env-cmdrc.json'];
+const ENV_FILE_DEFAULT_LOCATIONS = ['./.env', './.env.js', './.env.json'];
+async function getEnvVars(options = {}) {
+    options.envFile = options.envFile !== undefined ? options.envFile : {};
+    // Check for rc file usage
+    if (options.rc !== undefined) {
+        return getRCFile({ environments: options.rc.environments, filePath: options.rc.filePath });
+    }
+    return getEnvFile({ filePath: options.envFile.filePath, fallback: options.envFile.fallback });
+}
+exports.getEnvVars = getEnvVars;
+async function getEnvFile({ filePath, fallback }) {
+    // Use env file
+    if (filePath !== undefined) {
+        try {
+            return await parse_env_file_1.getEnvFileVars(filePath);
+        }
+        catch (e) { }
+        if (fallback !== true) {
+            throw new Error(`Unable to locate env file at location (${filePath})`);
+        }
+    }
+    // Use the default env file locations
+    for (const path of ENV_FILE_DEFAULT_LOCATIONS) {
+        try {
+            return await parse_env_file_1.getEnvFileVars(path);
+        }
+        catch (e) { }
+    }
+    throw new Error(`Unable to locate env file at default locations (${ENV_FILE_DEFAULT_LOCATIONS})`);
+}
+exports.getEnvFile = getEnvFile;
+async function getRCFile({ environments, filePath }) {
+    // User provided an .rc file path
+    if (filePath !== undefined) {
+        try {
+            return await parse_rc_file_1.getRCFileVars({ environments, filePath });
+        }
+        catch (e) {
+            if (e.name !== 'PathError')
+                console.error(e);
+            throw new Error(`Unable to locate .rc file at location (${filePath})`);
+        }
+    }
+    // Use the default .rc file locations
+    for (const filePath of RC_FILE_DEFAULT_LOCATIONS) {
+        try {
+            return await parse_rc_file_1.getRCFileVars({ environments, filePath });
+        }
+        catch (e) {
+            if (e.name !== 'PathError')
+                console.error(e);
+        }
+    }
+    throw new Error(`Unable to locate .rc file at default locations (${RC_FILE_DEFAULT_LOCATIONS})`);
+}
+exports.getRCFile = getRCFile;
diff --git a/dist/index.d.ts b/dist/src/index.d.ts
similarity index 100%
rename from dist/index.d.ts
rename to dist/src/index.d.ts
diff --git a/dist/index.js b/dist/src/index.js
similarity index 100%
rename from dist/index.js
rename to dist/src/index.js
diff --git a/dist/parse-args.d.ts b/dist/src/parse-args.d.ts
similarity index 100%
rename from dist/parse-args.d.ts
rename to dist/src/parse-args.d.ts
diff --git a/dist/parse-args.js b/dist/src/parse-args.js
similarity index 83%
rename from dist/parse-args.js
rename to dist/src/parse-args.js
index 7419174..11d93df 100644
--- a/dist/parse-args.js
+++ b/dist/src/parse-args.js
@@ -15,16 +15,18 @@ function parseArgs(args) {
     const noOverride = !program.override;
     const useShell = !!program.useShell;
     let rc;
-    if (program.environments && program.environments.length) {
-        rc = rc || {};
-        rc.environments = program.environments;
-        rc.filePath = program.rcFile;
+    if (program.environments !== undefined && program.environments.length !== 0) {
+        rc = {
+            environments: program.environments,
+            filePath: program.rcFile
+        };
     }
     let envFile;
-    if (program.file) {
-        envFile = envFile || {};
-        envFile.filePath = program.file;
-        envFile.fallback = program.fallback;
+    if (program.file !== undefined) {
+        envFile = {
+            filePath: program.file,
+            fallback: program.fallback
+        };
     }
     return {
         command,
diff --git a/dist/parse-env-file.d.ts b/dist/src/parse-env-file.d.ts
similarity index 100%
rename from dist/parse-env-file.d.ts
rename to dist/src/parse-env-file.d.ts
diff --git a/dist/parse-env-file.js b/dist/src/parse-env-file.js
similarity index 95%
rename from dist/parse-env-file.js
rename to dist/src/parse-env-file.js
index 57ff58a..c049c5c 100644
--- a/dist/parse-env-file.js
+++ b/dist/src/parse-env-file.js
@@ -15,7 +15,7 @@ async function getEnvFileVars(envFilePath) {
     // Get the file extension
     const ext = path.extname(absolutePath).toLowerCase();
     let env = {};
-    if (~REQUIRE_HOOK_EXTENSIONS.indexOf(ext)) {
+    if (REQUIRE_HOOK_EXTENSIONS.indexOf(ext) > -1) {
         const possiblePromise = require(absolutePath); /* eslint-disable-line */
         env = utils_1.isPromise(possiblePromise) ? await possiblePromise : possiblePromise;
     }
@@ -48,11 +48,11 @@ function parseEnvVars(envString) {
     while ((match = envParseRegex.exec(envString)) !== null) {
         // Note: match[1] is the full env=var line
         const key = match[2].trim();
-        const value = match[3].trim() || '';
+        const value = match[3].trim();
         // remove any surrounding quotes
         matches[key] = value
             .replace(/(^['"]|['"]$)/g, '')
-            .replace(/\\n/g, `\n`);
+            .replace(/\\n/g, '\n');
     }
     return matches;
 }
diff --git a/dist/parse-rc-file.d.ts b/dist/src/parse-rc-file.d.ts
similarity index 100%
rename from dist/parse-rc-file.d.ts
rename to dist/src/parse-rc-file.d.ts
diff --git a/dist/parse-rc-file.js b/dist/src/parse-rc-file.js
similarity index 95%
rename from dist/parse-rc-file.js
rename to dist/src/parse-rc-file.js
index 1c00e4e..b8a6f3e 100644
--- a/dist/parse-rc-file.js
+++ b/dist/src/parse-rc-file.js
@@ -35,7 +35,7 @@ async function getRCFileVars({ environments, filePath }) {
     let environmentFound = false;
     environments.forEach((name) => {
         const envVars = parsedData[name];
-        if (envVars) {
+        if (envVars !== undefined) {
             environmentFound = true;
             result = Object.assign({}, result, envVars);
         }
@@ -63,7 +63,7 @@ function parseRCFile(fileData) {
         console.error(`Error:
   Failed to parse the .rc file.
   Please make sure its a valid JSON format.`);
-        throw new Error(`Unable to parse JSON in .rc file.`);
+        throw new Error('Unable to parse JSON in .rc file.');
     }
     return data;
 }
diff --git a/dist/signal-termination.d.ts b/dist/src/signal-termination.d.ts
similarity index 91%
rename from dist/signal-termination.d.ts
rename to dist/src/signal-termination.d.ts
index e7d97fd..18a2b35 100644
--- a/dist/signal-termination.d.ts
+++ b/dist/src/signal-termination.d.ts
@@ -1,7 +1,7 @@
 /// <reference types="node" />
 import { ChildProcess } from 'child_process';
 export declare class TermSignals {
-    private terminateSpawnedProcessFuncHandlers;
+    private readonly terminateSpawnedProcessFuncHandlers;
     _exitCalled: boolean;
     handleTermSignals(proc: ChildProcess): void;
     /**
diff --git a/dist/signal-termination.js b/dist/src/signal-termination.js
similarity index 95%
rename from dist/signal-termination.js
rename to dist/src/signal-termination.js
index 0ee320b..d0a59b9 100644
--- a/dist/signal-termination.js
+++ b/dist/src/signal-termination.js
@@ -22,7 +22,7 @@ class TermSignals {
                 };
             process.once(signal, this.terminateSpawnedProcessFuncHandlers[signal]);
         });
-        process.once('exit', this.terminateSpawnedProcessFuncHandlers['SIGTERM']);
+        process.once('exit', this.terminateSpawnedProcessFuncHandlers.SIGTERM);
         // Terminate parent process if child process receives termination events
         proc.on('exit', (code, signal) => {
             this._removeProcessListeners();
@@ -42,10 +42,10 @@ class TermSignals {
      * Terminate parent process helper
      */
     _terminateProcess(code, signal) {
-        if (signal != null) {
+        if (signal !== undefined) {
             return process.kill(process.pid, signal);
         }
-        if (code != null) {
+        if (code !== undefined) {
             return process.exit(code);
         }
         throw new Error('Unable to terminate parent process successfully');
@@ -57,7 +57,7 @@ class TermSignals {
         SIGNALS_TO_HANDLE.forEach((signal) => {
             process.removeListener(signal, this.terminateSpawnedProcessFuncHandlers[signal]);
         });
-        process.removeListener('exit', this.terminateSpawnedProcessFuncHandlers['SIGTERM']);
+        process.removeListener('exit', this.terminateSpawnedProcessFuncHandlers.SIGTERM);
     }
     /**
     * General exception handler
diff --git a/dist/spawn.d.ts b/dist/src/spawn.d.ts
similarity index 100%
rename from dist/spawn.d.ts
rename to dist/src/spawn.d.ts
diff --git a/dist/spawn.js b/dist/src/spawn.js
similarity index 100%
rename from dist/spawn.js
rename to dist/src/spawn.js
diff --git a/dist/types.d.ts b/dist/src/types.d.ts
similarity index 100%
rename from dist/types.d.ts
rename to dist/src/types.d.ts
diff --git a/dist/types.js b/dist/src/types.js
similarity index 100%
rename from dist/types.js
rename to dist/src/types.js
diff --git a/dist/utils.d.ts b/dist/src/utils.d.ts
similarity index 93%
rename from dist/utils.d.ts
rename to dist/src/utils.d.ts
index 13e3d81..d3714a7 100644
--- a/dist/utils.d.ts
+++ b/dist/src/utils.d.ts
@@ -9,4 +9,4 @@ export declare function parseArgList(list: string): string[];
 /**
  * A simple function to test if the value is a promise
  */
-export declare function isPromise(value: any | PromiseLike<Object>): boolean;
+export declare function isPromise(value: any | PromiseLike<Object>): value is Promise<any>;
diff --git a/dist/utils.js b/dist/src/utils.js
similarity index 89%
rename from dist/utils.js
rename to dist/src/utils.js
index 7b5dd9b..9ae5f6b 100644
--- a/dist/utils.js
+++ b/dist/src/utils.js
@@ -8,7 +8,7 @@ const os = require("os");
 function resolveEnvFilePath(userPath) {
     // Make sure a home directory exist
     const home = os.homedir();
-    if (home) {
+    if (home !== undefined) {
         userPath = userPath.replace(/^~($|\/|\\)/, `${home}$1`);
     }
     return path.resolve(process.cwd(), userPath);
@@ -25,6 +25,6 @@ exports.parseArgList = parseArgList;
  * A simple function to test if the value is a promise
  */
 function isPromise(value) {
-    return value && typeof value.then === 'function';
+    return value !== undefined && typeof value.then === 'function';
 }
 exports.isPromise = isPromise;
diff --git a/package.json b/package.json
index 454d722..b1b4782 100644
--- a/package.json
+++ b/package.json
@@ -2,8 +2,8 @@
   "name": "env-cmd",
   "version": "10.0.0",
   "description": "Executes a command using the environment variables in an env file",
-  "main": "dist/index.js",
-  "types": "dist/index.d.ts",
+  "main": "dist/src/index.js",
+  "types": "dist/src/index.d.ts",
   "engines": {
     "node": ">=8.0.0"
   },
@@ -48,7 +48,7 @@
   },
   "homepage": "https://github.com/toddbluhm/env-cmd#readme",
   "dependencies": {
-    "commander": "^2.0.0",
+    "commander": "^3.0.0",
     "cross-spawn": "^6.0.0"
   },
   "devDependencies": {
@@ -57,12 +57,13 @@
     "@types/mocha": "^5.0.0",
     "@types/node": "^12.0.0",
     "@types/sinon": "^7.0.0",
-    "@typescript-eslint/eslint-plugin": "^1.0.0",
-    "@typescript-eslint/parser": "^1.0.0",
+    "@typescript-eslint/eslint-plugin": "^2.0.0",
+    "@typescript-eslint/parser": "^2.0.0",
     "chai": "^4.0.0",
     "coveralls": "^3.0.0",
-    "eslint": "^5.0.0",
-    "eslint-config-standard-with-typescript": "^8.0.0",
+    "eslint": "^6.0.0",
+    "eslint-config-standard": "^14.0.0",
+    "eslint-config-standard-with-typescript": "toddbluhm/eslint-config-standard-with-typescript#compiled",
     "eslint-plugin-import": "^2.0.0",
     "eslint-plugin-node": "^9.0.0",
     "eslint-plugin-promise": "^4.0.0",
diff --git a/src/env-cmd.ts b/src/env-cmd.ts
index 0620cfa..bca2a91 100644
--- a/src/env-cmd.ts
+++ b/src/env-cmd.ts
@@ -32,12 +32,11 @@ export async function CLI (args: string[]): Promise<{ [key: string]: any }> {
  * @returns {Promise<{ [key: string]: any }>} Returns an object containing [environment variable name]: value
  */
 export async function EnvCmd (
-  { command, commandArgs, envFile, rc, options }: EnvCmdOptions
+  { command, commandArgs, envFile, rc, options = {} }: EnvCmdOptions
 ): Promise<{ [key: string]: any }> {
-  options = options || {}
   let env = await getEnvVars({ envFile, rc })
   // Override the merge order if --no-override flag set
-  if (options.noOverride) {
+  if (options.noOverride === true) {
     env = Object.assign({}, env, process.env)
   } else {
     // Add in the system environment variables to our environment list
diff --git a/src/get-env-vars.ts b/src/get-env-vars.ts
index 2dc662e..92eb446 100644
--- a/src/get-env-vars.ts
+++ b/src/get-env-vars.ts
@@ -5,11 +5,10 @@ import { getEnvFileVars } from './parse-env-file'
 const RC_FILE_DEFAULT_LOCATIONS = ['./.env-cmdrc', './.env-cmdrc.js', './.env-cmdrc.json']
 const ENV_FILE_DEFAULT_LOCATIONS = ['./.env', './.env.js', './.env.json']
 
-export async function getEnvVars (options?: GetEnvVarOptions): Promise<{ [key: string]: any }> {
-  options = options || {}
-  options.envFile = options.envFile || {}
+export async function getEnvVars (options: GetEnvVarOptions = {}): Promise<{ [key: string]: any }> {
+  options.envFile = options.envFile !== undefined ? options.envFile : {}
   // Check for rc file usage
-  if (options.rc) {
+  if (options.rc !== undefined) {
     return getRCFile({ environments: options.rc.environments, filePath: options.rc.filePath })
   }
   return getEnvFile({ filePath: options.envFile.filePath, fallback: options.envFile.fallback })
@@ -19,11 +18,11 @@ export async function getEnvFile (
   { filePath, fallback }: { filePath?: string, fallback?: boolean }
 ): Promise<{ [key: string]: any }> {
   // Use env file
-  if (filePath) {
+  if (filePath !== undefined) {
     try {
       return await getEnvFileVars(filePath)
     } catch (e) { }
-    if (!fallback) {
+    if (fallback !== true) {
       throw new Error(`Unable to locate env file at location (${filePath})`)
     }
   }
@@ -42,11 +41,11 @@ export async function getRCFile (
   { environments, filePath }: { environments: string[], filePath?: string }
 ): Promise<{ [key: string]: any }> {
   // User provided an .rc file path
-  if (filePath) {
+  if (filePath !== undefined) {
     try {
       return await getRCFileVars({ environments, filePath })
     } catch (e) {
-      if (e.name !== 'PathError') console.log(e)
+      if (e.name !== 'PathError') console.error(e)
       throw new Error(`Unable to locate .rc file at location (${filePath})`)
     }
   }
@@ -56,7 +55,7 @@ export async function getRCFile (
     try {
       return await getRCFileVars({ environments, filePath })
     } catch (e) {
-      if (e.name !== 'PathError') console.log(e)
+      if (e.name !== 'PathError') console.error(e)
     }
   }
 
diff --git a/src/parse-args.ts b/src/parse-args.ts
index b8a0e16..7d09b1a 100644
--- a/src/parse-args.ts
+++ b/src/parse-args.ts
@@ -13,21 +13,23 @@ export function parseArgs (args: string[]): EnvCmdOptions {
 
   // Reprocess the args with the command and command args removed
   program = parseArgsUsingCommander(args.slice(0, args.indexOf(command)))
-  const noOverride = !program.override
-  const useShell = !!program.useShell
+  const noOverride = !(program.override as boolean)
+  const useShell = !!(program.useShell as boolean)
 
   let rc: any
-  if (program.environments && program.environments.length) {
-    rc = rc || {}
-    rc.environments = program.environments
-    rc.filePath = program.rcFile
+  if (program.environments !== undefined && program.environments.length !== 0) {
+    rc = {
+      environments: program.environments,
+      filePath: program.rcFile
+    }
   }
 
   let envFile: any
-  if (program.file) {
-    envFile = envFile || {}
-    envFile.filePath = program.file
-    envFile.fallback = program.fallback
+  if (program.file !== undefined) {
+    envFile = {
+      filePath: program.file,
+      fallback: program.fallback
+    }
   }
 
   return {
diff --git a/src/parse-env-file.ts b/src/parse-env-file.ts
index 12869cc..d505309 100644
--- a/src/parse-env-file.ts
+++ b/src/parse-env-file.ts
@@ -16,7 +16,7 @@ export async function getEnvFileVars (envFilePath: string): Promise<{ [key: stri
   // Get the file extension
   const ext = path.extname(absolutePath).toLowerCase()
   let env = {}
-  if (~REQUIRE_HOOK_EXTENSIONS.indexOf(ext)) {
+  if (REQUIRE_HOOK_EXTENSIONS.indexOf(ext) > -1) {
     const possiblePromise = require(absolutePath) /* eslint-disable-line */
     env = isPromise(possiblePromise) ? await possiblePromise : possiblePromise
   } else {
@@ -50,12 +50,12 @@ export function parseEnvVars (envString: string): { [key: string]: string } {
   while ((match = envParseRegex.exec(envString)) !== null) {
     // Note: match[1] is the full env=var line
     const key = match[2].trim()
-    const value = match[3].trim() || ''
+    const value = match[3].trim()
 
     // remove any surrounding quotes
     matches[key] = value
       .replace(/(^['"]|['"]$)/g, '')
-      .replace(/\\n/g, `\n`)
+      .replace(/\\n/g, '\n')
   }
   return matches
 }
diff --git a/src/parse-rc-file.ts b/src/parse-rc-file.ts
index 96cae4a..77833f0 100644
--- a/src/parse-rc-file.ts
+++ b/src/parse-rc-file.ts
@@ -38,7 +38,7 @@ export async function getRCFileVars (
   let environmentFound = false
   environments.forEach((name): void => {
     const envVars = parsedData[name]
-    if (envVars) {
+    if (envVars !== undefined) {
       environmentFound = true
       result = {
         ...result,
@@ -70,7 +70,7 @@ export function parseRCFile (fileData: string): { [key: string]: any } {
     console.error(`Error:
   Failed to parse the .rc file.
   Please make sure its a valid JSON format.`)
-    throw new Error(`Unable to parse JSON in .rc file.`)
+    throw new Error('Unable to parse JSON in .rc file.')
   }
   return data
 }
diff --git a/src/signal-termination.ts b/src/signal-termination.ts
index 8a8c7d6..3c3e308 100644
--- a/src/signal-termination.ts
+++ b/src/signal-termination.ts
@@ -5,7 +5,7 @@ const SIGNALS_TO_HANDLE: NodeJS.Signals[] = [
 ]
 
 export class TermSignals {
-  private terminateSpawnedProcessFuncHandlers: { [key: string]: any } = {}
+  private readonly terminateSpawnedProcessFuncHandlers: { [key: string]: any } = {}
   public _exitCalled = false
 
   public handleTermSignals (proc: ChildProcess): void {
@@ -22,7 +22,7 @@ export class TermSignals {
         }
       process.once(signal, this.terminateSpawnedProcessFuncHandlers[signal])
     })
-    process.once('exit', this.terminateSpawnedProcessFuncHandlers['SIGTERM'])
+    process.once('exit', this.terminateSpawnedProcessFuncHandlers.SIGTERM)
 
     // Terminate parent process if child process receives termination events
     proc.on('exit', (code: number | undefined, signal: string | undefined): void => {
@@ -45,10 +45,10 @@ export class TermSignals {
    * Terminate parent process helper
    */
   public _terminateProcess (code?: number, signal?: string): void {
-    if (signal != null) {
+    if (signal !== undefined) {
       return process.kill(process.pid, signal)
     }
-    if (code != null) {
+    if (code !== undefined) {
       return process.exit(code)
     }
     throw new Error('Unable to terminate parent process successfully')
@@ -61,7 +61,7 @@ export class TermSignals {
     SIGNALS_TO_HANDLE.forEach((signal): void => {
       process.removeListener(signal, this.terminateSpawnedProcessFuncHandlers[signal])
     })
-    process.removeListener('exit', this.terminateSpawnedProcessFuncHandlers['SIGTERM'])
+    process.removeListener('exit', this.terminateSpawnedProcessFuncHandlers.SIGTERM)
   }
 
   /**
diff --git a/src/utils.ts b/src/utils.ts
index 086b50d..548a8cd 100644
--- a/src/utils.ts
+++ b/src/utils.ts
@@ -7,7 +7,7 @@ import * as os from 'os'
 export function resolveEnvFilePath (userPath: string): string {
   // Make sure a home directory exist
   const home = os.homedir()
-  if (home) {
+  if (home !== undefined) {
     userPath = userPath.replace(/^~($|\/|\\)/, `${home}$1`)
   }
   return path.resolve(process.cwd(), userPath)
@@ -22,6 +22,6 @@ export function parseArgList (list: string): string[] {
 /**
  * A simple function to test if the value is a promise
  */
-export function isPromise (value: any | PromiseLike<Object>): boolean {
-  return value && typeof value.then === 'function'
+export function isPromise (value: any | PromiseLike<Object>): value is Promise<any> {
+  return value !== undefined && typeof value.then === 'function'
 }
diff --git a/test/get-env-vars.spec.ts b/test/get-env-vars.spec.ts
index a51f24a..b42c8eb 100644
--- a/test/get-env-vars.spec.ts
+++ b/test/get-env-vars.spec.ts
@@ -7,6 +7,7 @@ import * as envFile from '../src/parse-env-file'
 describe('getEnvVars', (): void => {
   let getRCFileVarsStub: sinon.SinonStub<any, any>
   let getEnvFileVarsStub: sinon.SinonStub<any, any>
+  let logStub: sinon.SinonStub<any, any>
 
   const pathError = new Error()
   pathError.name = 'PathError'
@@ -14,6 +15,7 @@ describe('getEnvVars', (): void => {
   before((): void => {
     getRCFileVarsStub = sinon.stub(rcFile, 'getRCFileVars')
     getEnvFileVarsStub = sinon.stub(envFile, 'getEnvFileVars')
+    logStub = sinon.stub(console, 'error')
   })
 
   after((): void => {
@@ -62,6 +64,17 @@ describe('getEnvVars', (): void => {
     }
   })
 
+  it('should log to error console on non-path errors', async (): Promise<void> => {
+    getRCFileVarsStub.rejects(new Error('Non-path Error'))
+    try {
+      await getEnvVars({ rc: { environments: ['production'] } })
+      assert.fail('should not get here.')
+    } catch (e) {
+      assert.match(logStub.getCall(0).args[0].message, /non-path error/gi)
+      assert.match(e.message, /locate \.rc/gi)
+    }
+  })
+
   it('should find .rc file at custom path location', async (): Promise<void> => {
     getRCFileVarsStub.returns({ THANKS: 'FORALLTHEFISH' })
     const envs = await getEnvVars({
@@ -84,7 +97,19 @@ describe('getEnvVars', (): void => {
       })
       assert.fail('should not get here.')
     } catch (e) {
-      console.log(e)
+      assert.match(e.message, /locate \.rc/gi)
+    }
+  })
+
+  it('should log to error console on non-path errors', async (): Promise<void> => {
+    getRCFileVarsStub.rejects(new Error('Non-path Error'))
+    try {
+      await getEnvVars({
+        rc: { environments: ['production'], filePath: '../.custom-rc' }
+      })
+      assert.fail('should not get here.')
+    } catch (e) {
+      assert.match(logStub.getCall(0).args[0].message, /non-path error/gi)
       assert.match(e.message, /locate \.rc/gi)
     }
   })
diff --git a/test/parse-env-file.spec.ts b/test/parse-env-file.spec.ts
index 42d6a95..0ddcdcc 100644
--- a/test/parse-env-file.spec.ts
+++ b/test/parse-env-file.spec.ts
@@ -63,7 +63,7 @@ describe('parseEnvVars', (): void => {
   })
 
   it('should preserve newlines when surrounded in quotes', (): void => {
-    const envVars = parseEnvVars(`ONE_NEWLINE="ONE\\n"\nTWO_NEWLINES="HELLO\\nWORLD\\n"\nTHREE_NEWLINES="HELLO\\n\\nWOR\\nLD"\n`)
+    const envVars = parseEnvVars('ONE_NEWLINE="ONE\\n"\nTWO_NEWLINES="HELLO\\nWORLD\\n"\nTHREE_NEWLINES="HELLO\\n\\nWOR\\nLD"\n')
     assert(envVars.ONE_NEWLINE === 'ONE\n')
     assert(envVars.TWO_NEWLINES === 'HELLO\nWORLD\n')
     assert(envVars.THREE_NEWLINES === 'HELLO\n\nWOR\nLD')
@@ -104,47 +104,47 @@ describe('getEnvFileVars', (): void => {
   it('should parse a json file', async (): Promise<void> => {
     const env = await getEnvFileVars('./test/test-files/test.json')
     assert.deepEqual(env, {
-      'THANKS': 'FOR WHAT?!',
-      'ANSWER': 42,
-      'ONLY': 'IN PRODUCTION',
-      'GALAXY': 'hitch\nhiking'
+      THANKS: 'FOR WHAT?!',
+      ANSWER: 42,
+      ONLY: 'IN PRODUCTION',
+      GALAXY: 'hitch\nhiking'
     })
   })
 
   it('should parse a json file keeping all newlines intact', async (): Promise<void> => {
     const env = await getEnvFileVars('./test/test-files/test-newlines.json')
     assert.deepEqual(env, {
-      'THANKS': 'FOR WHAT?!',
-      'ANSWER': 42,
-      'ONLY': 'IN\n PRODUCTION',
-      'GALAXY': 'hitch\nhiking\n\n'
+      THANKS: 'FOR WHAT?!',
+      ANSWER: 42,
+      ONLY: 'IN\n PRODUCTION',
+      GALAXY: 'hitch\nhiking\n\n'
     })
   })
 
   it('should parse a js file', async (): Promise<void> => {
     const env = await getEnvFileVars('./test/test-files/test.js')
     assert.deepEqual(env, {
-      'THANKS': 'FOR ALL THE FISH',
-      'ANSWER': 0,
-      'GALAXY': 'hitch\nhiking'
+      THANKS: 'FOR ALL THE FISH',
+      ANSWER: 0,
+      GALAXY: 'hitch\nhiking'
     })
   })
 
   it('should parse an async js file', async (): Promise<void> => {
     const env = await getEnvFileVars('./test/test-files/test-async.js')
     assert.deepEqual(env, {
-      'THANKS': 'FOR ALL THE FISH',
-      'ANSWER': 0
+      THANKS: 'FOR ALL THE FISH',
+      ANSWER: 0
     })
   })
 
   it('should parse an env file', async (): Promise<void> => {
     const env = await getEnvFileVars('./test/test-files/test')
     assert.deepEqual(env, {
-      'THANKS': 'FOR WHAT?!',
-      'ANSWER': '42',
-      'ONLY': 'IN=PRODUCTION',
-      'GALAXY': 'hitch\nhiking'
+      THANKS: 'FOR WHAT?!',
+      ANSWER: '42',
+      ONLY: 'IN=PRODUCTION',
+      GALAXY: 'hitch\nhiking'
     })
   })
 
diff --git a/test/parse-rc-file.spec.ts b/test/parse-rc-file.spec.ts
index a71a948..eb793e5 100644
--- a/test/parse-rc-file.spec.ts
+++ b/test/parse-rc-file.spec.ts
@@ -30,9 +30,9 @@ describe('getRCFileVars', (): void => {
     const res = await getRCFileVars({ environments: ['production'], filePath: rcFilePath })
     assert.exists(res)
     assert.deepEqual(res, {
-      'THANKS': 'FOR WHAT?!',
-      'ANSWER': 42,
-      'ONLY': 'IN PRODUCTION'
+      THANKS: 'FOR WHAT?!',
+      ANSWER: 42,
+      ONLY: 'IN PRODUCTION'
     })
   })
 
@@ -40,8 +40,8 @@ describe('getRCFileVars', (): void => {
     const res = await getRCFileVars({ environments: ['test'], filePath: rcJSONFilePath })
     assert.exists(res)
     assert.deepEqual(res, {
-      'THANKS': 'FOR MORE FISHIES',
-      'ANSWER': 21
+      THANKS: 'FOR MORE FISHIES',
+      ANSWER: 21
     })
   })
 
@@ -69,9 +69,9 @@ describe('getRCFileVars', (): void => {
       filePath: './test/test-files/.rc-test-async.js'
     })
     assert.deepEqual(env, {
-      'THANKS': 'FOR WHAT?!',
-      'ANSWER': 42,
-      'ONLY': 'IN PRODUCTION'
+      THANKS: 'FOR WHAT?!',
+      ANSWER: 42,
+      ONLY: 'IN PRODUCTION'
     })
   })
 })
diff --git a/tsconfig.json b/tsconfig.json
index 3d0ff9b..bb3885c 100644
--- a/tsconfig.json
+++ b/tsconfig.json
@@ -10,6 +10,7 @@
     ]
   },
   "include": [
-    "./src/**/*"
+    "./src/**/*",
+    "./test/**/*"
   ]
 }
\ No newline at end of file