handle multi-component objects and ambiguous package paths

packages/mjml-core/src/helpers/mjmlconfig.js

@@ -3,15 +3,6 @@ import fs from 'fs'
 
 import { registerComponent } from '../components'
 
-export function resolveComponentPath(compPath, componentRootPath) {
-  if (!compPath) {
-    return null
-  } else if (compPath.startsWith('.') || path.isAbsolute(compPath)) {
-    return path.resolve(componentRootPath, compPath)
-  }
-  return require.resolve(compPath)
-}
-
 export function readMjmlConfig(configPathOrDir = process.cwd()) {
   let componentRootPath = process.cwd()
   let mjmlConfigPath = configPathOrDir
@@ -30,14 +21,45 @@ export function readMjmlConfig(configPathOrDir = process.cwd()) {
   }
 }
 
+
+export function resolveComponentPath(compPath, componentRootPath) {
+  if (!compPath) {
+    return null
+  }
+  if (!compPath.startsWith('.') && !path.isAbsolute(compPath)) {
+    try {
+      return require.resolve(compPath)
+    } catch (e) {
+      if (e.code !== 'MODULE_NOT_FOUND') {
+        console.log('Error resolving custom component path : ', e) // eslint-disable-line no-console
+        return null
+      }
+      // if we get a 'MODULE_NOT_FOUND' error try again with relative path:
+      return resolveComponentPath(`./${compPath}`, componentRootPath)
+    }
+  }
+  return require.resolve(path.resolve(componentRootPath, compPath))
+}
+
+export function registerCustomComponent(comp, registerCompFn = registerComponent) {
+  if (comp instanceof Function) {
+    registerCompFn(comp)
+  } else {
+    const compNames = Object.keys(comp) // this approach handles both an array and 
+    compNames.forEach(compName => {
+      registerCustomComponent(comp[compName], registerCompFn)
+    })
+  }
+}
+
 export default function registerCustomComponents(configPathOrDir = process.cwd(), registerCompFn = registerComponent) {
   const { mjmlConfig: { packages }, componentRootPath } = readMjmlConfig(configPathOrDir)
   packages.forEach(compPath => {
     const resolvedPath = resolveComponentPath(compPath, componentRootPath)
     if (resolvedPath) {
       try {
         const requiredComp = require(resolvedPath) // eslint-disable-line global-require, import/no-dynamic-require
-        registerCompFn(requiredComp.default || requiredComp)
+        registerCustomComponent(requiredComp.default || requiredComp, registerCompFn)
       } catch (e) {
         if (e.code !== 'ENOENT') {
           console.log('Error when registering custom component : ', resolvedPath, e) // eslint-disable-line no-console