refactor: remove usage of _.isEmpty

Author: mjeanroy

src/dependency.js

@@ -96,7 +96,7 @@ export class Dependency {
       lines.push(`Author: ${this.author.text()}`);
     }
 
-    if (!_.isEmpty(this.contributors)) {
+    if (this.contributors.length > 0) {
       lines.push(`Contributors:`);
 
       const allContributors = _.chain(this.contributors)

src/license-plugin-option.js

@@ -134,7 +134,7 @@ function doValidation(options) {
  */
 function validateOptions(options) {
   const errors = doValidation(options);
-  if (_.isEmpty(errors)) {
+  if (errors.length === 0) {
     return;
   }
 
@@ -148,7 +148,7 @@ function validateOptions(options) {
     }
   });
 
-  if (!_.isEmpty(messages)) {
+  if (messages.length > 0) {
     throw new Error(
         `[${PLUGIN_NAME}] -- Error during validation of option object: ${messages.join(' ; ')}`,
     );

src/license-plugin.js

@@ -565,7 +565,7 @@ class LicensePlugin {
     // Allow custom formatting of output using given template option.
     const template = _.isString(output.template) ? (dependencies) => _.template(output.template)({dependencies, _, moment}) : output.template;
     const defaultTemplate = (dependencies) => (
-      _.isEmpty(dependencies) ? 'No third parties dependencies' : _.map(dependencies, (d) => d.text()).join(`${EOL}${EOL}---${EOL}${EOL}`)
+      dependencies.length === 0 ? 'No third parties dependencies' : _.map(dependencies, (d) => d.text()).join(`${EOL}${EOL}---${EOL}${EOL}`)
     );
 
     const text = _.isFunction(template) ? template(outputDependencies) : defaultTemplate(outputDependencies);

src/schema-validator.js

@@ -39,7 +39,7 @@ function doItemValidation(value, schema, path) {
   const matchedValidators = _.filter(validators, (validator) => validator.test(value));
 
   // No one matched, we can stop here and return an error with a proper message.
-  if (_.isEmpty(matchedValidators)) {
+  if (matchedValidators.length === 0) {
     return [
       {
         path,