Add flag to force Node colors

So that process that runs in Electron renderer process can log to
the terminal if it runs in a headless mode, but to the browser console
if it runs with the browser window.

Use case: run browser tests in electron-mocha renderer with or without
browser window.

README.md

@@ -168,6 +168,7 @@ change the behavior of the debug logging:
 | `DEBUG`   | Enables/disables specific debugging namespaces. |
 | `DEBUG_HIDE_DATE` | Hide date from debug output (non-TTY).  |
 | `DEBUG_COLORS`| Whether or not to use colors in the debug output. |
+| `DEBUG_COLORS_NODE` | Assume runtime is Node, even if it looks like a browser (e.g. Electron). |
 | `DEBUG_DEPTH` | Object inspection depth.                    |
 | `DEBUG_SHOW_HIDDEN` | Shows hidden properties on inspected objects. |
 

src/index.js

@@ -3,7 +3,10 @@
  * treat as a browser.
  */
 
-if (typeof process === 'undefined' || process.type === 'renderer' || process.browser === true || process.__nwjs) {
+const isBrowserNode = process.type === 'renderer' || process.browser === true || process.__nwjs;
+const isBrowser = typeof process === 'undefined';
+
+if (isBrowser || (isBrowserNode && !process.env.DEBUG_COLORS_NODE)) {
 	module.exports = require('./browser.js');
 } else {
 	module.exports = require('./node.js');

src/node.js

@@ -128,6 +128,11 @@ exports.inspectOpts = Object.keys(process.env).filter(key => {
 			return k.toUpperCase();
 		});
 
+	if (prop === 'colorsNode') {
+		obj.colors = true;
+		return obj;
+	}
+
 	// Coerce string value into JS value
 	let val = process.env[key];
 	if (/^(yes|on|true|enabled)$/i.test(val)) {