feat: more conservative configuration detection

* Make a loud debug message if there is no configuration file found
* Throw an error if there is a configuration file but it is empty. This
  can happen if you misspell modules.exports as module.export and you
  use a .js file.

lib/definitions/errors.js

@@ -11,6 +11,14 @@ const wordsList = (words) =>
   `${words.slice(0, -1).join(', ')}${words.length > 1 ? ` or ${words[words.length - 1]}` : trim(words[0])}`;
 
 module.exports = {
+  ECONFIGNOTFOUND: () => ({
+    message: 'Your release configuration file was NOT found',
+    details: `We could not found a config file, proceeding with only the defaults`,
+  }),
+  EEMPTYCONFIG: ({filepath}) => ({
+    message: 'Your release configuration was found but has no contents',
+    details: `Please verify your config file ${filepath} is present with content`,
+  }),
   ENOGITREPO: ({cwd}) => ({
     message: 'Not running from a git repository.',
     details: `The \`semantic-release\` command must be executed from a Git repository.

lib/get-config.js

@@ -7,6 +7,7 @@ const {repoUrl} = require('./git');
 const PLUGINS_DEFINITIONS = require('./definitions/plugins');
 const plugins = require('./plugins');
 const {validatePlugin, parseConfig} = require('./plugins/utils');
+const getError = require('./get-error');
 
 const CONFIG_NAME = 'release';
 
@@ -36,6 +37,14 @@ const DEFAULTS = {
 module.exports = async (context, cliOptions) => {
   const {cwd, env} = context;
   const {config, filepath} = (await cosmiconfig(CONFIG_NAME).search(cwd)) || {};
+
+  if ( filepath === undefined ) {
+    debug( getError('ECONFIGNOTFOUND') );
+  }
+  // Will trigger if the file is .js but doesn't set modules.exports
+  else if ( Object.prototype.constructor.keys(config||{}).length == 0 ) {
+    throw getError('EEMPTYCONFIG', {filepath});
+  }
 
   // Merge config file options and CLI/API options
   let options = {...config, ...cliOptions};