Fix resolve legacy requires

Closes #191

Author: inukshuk

lib/mocha.js

@@ -3,6 +3,7 @@
 const Mocha = require('mocha')
 const errors = require('mocha/lib/errors')
 const { resolve } = require('path')
+const { existsSync } = require('fs')
 
 const {
   handleRequires,
@@ -16,15 +17,24 @@ const {
   ONE_AND_DONES
 } = require('mocha/lib/cli/one-and-dones')
 
+const cwd = process.cwd()
+
+const handleLegacyRequires = async (mods) => {
+  for (let mod of mods) {
+    if (existsSync(mod, { cwd }) || existsSync(`${mod}.js`, { cwd })) {
+      mod = resolve(mod)
+    }
+    require(mod)
+  }
+}
+
 const runMocha = async (argv, done) => {
   Error.stackTraceLimit = Infinity
 
   if (process.type === 'renderer') {
     // Node.js ESM loader is not available in Electron Renderer
     // so we require dependencies explicitly here.
-    for (const mod of argv.require) {
-      require(resolve(mod))
-    }
+    await handleLegacyRequires(argv.require)
   } else {
     await handleRequires(argv.require)
   }
@@ -50,6 +60,7 @@ module.exports = {
   errors,
   helpers: {
     handleRequires,
+    handleLegacyRequires,
     runMocha
   }
 }

lib/run.js

@@ -130,9 +130,6 @@ exports.builder = yargs => {
         argv.inspect = true
       }
 
-      if (argv['require-main']) {
-        argv['require-main'] = argv['require-main'].map(script => resolve(script))
-      }
       if (argv.script) {
         argv.script = argv.script.map(script => resolve(script))
       }
@@ -152,9 +149,7 @@ exports.builder = yargs => {
 exports.handler = async argv => {
   try {
     if (argv['require-main']) {
-      for (const mod of argv['require-main']) {
-        require(mod)
-      }
+      await helpers.handleLegacyRequires(argv['require-main'])
     }
 
     await app.whenReady()