test: add snapshot image tests for rgba w/o alpha value

build/lib/test/test.js

@@ -77,7 +77,19 @@ async function test(platforms, target, deviceId, deployType, deviceFamily, snaps
 
 		// If we're gathering images, make sure we get them all before we move on
 		if (snapshotPromises.length !== 0) {
-			await Promise.all(snapshotPromises);
+			try {
+				await Promise.all(snapshotPromises);
+			} catch (err) {
+				// If grabbing an image fails, can we report more details about why?
+				// The rejected error should have stdout/stderr properties
+				if (err.stderr) {
+					console.error(err.stderr);
+				}
+				if (err.stdout) {
+					console.log(err.stdout);
+				}
+				throw err;
+			}
 		}
 
 		return results;

tests/Resources/ti.ui.view.test.js

@@ -1322,4 +1322,37 @@ describe('Titanium.UI.View', function () {
 		const view2 = Ti.UI.createView({ filterTouchesWhenObscured: true });
 		should(view2.filterTouchesWhenObscured).be.true();
 	});
+
+	it('rgba fallback', finish => {
+		if (isCI && utilities.isMacOS()) { // some of the CI mac nodes lie about their scale, which makes the image comparison fail
+			return finish(); // FIXME: skip when we move to official mocha package
+		}
+		win = Ti.UI.createWindow({ backgroundColor: '#fff' });
+		const rgbaView = Ti.UI.createView({
+			width: 100,
+			height: 100,
+			backgroundColor: 'rgba(255,0,0)',
+			left: 0
+		});
+		const rgbView = Ti.UI.createView({
+			width: 100,
+			height: 100,
+			backgroundColor: 'rgb(0,255,0)',
+			left: 100
+		});
+
+		win.addEventListener('postlayout', function postlayout() { // FIXME: Support once!
+			win.removeEventListener('postlayout', postlayout); // only run once
+			try {
+				should(rgbaView).matchImage('snapshots/rgbaView_red.png');
+				should(rgbView).matchImage('snapshots/rgbView_green.png');
+			} catch (err) {
+				return finish(err);
+			}
+			finish();
+		});
+		win.add(rgbaView);
+		win.add(rgbView);
+		win.open();
+	});
 });