Handle app without an icon

Fixes #51

cli.js

@@ -79,7 +79,6 @@ async function init() {
 	}
 
 	const appName = appInfo.CFBundleDisplayName || appInfo.CFBundleName;
-	const appIconName = appInfo.CFBundleIconFile.replace(/\.icns/, '');
 	const dmgTitle = appName.length > 27 ? (cli.flags.dmgTitle || appName) : appName;
 	const dmgPath = path.join(destinationPath, `${appName} ${appInfo.CFBundleShortVersionString}.dmg`);
 
@@ -89,8 +88,13 @@ async function init() {
 		} catch (_) {}
 	}
 
-	ora.text = 'Creating icon';
-	const composedIconPath = await composeIcon(path.join(appPath, 'Contents/Resources', `${appIconName}.icns`));
+	const hasAppIcon = appInfo.CFBundleIconFile;
+	let composedIconPath;
+	if (hasAppIcon) {
+		ora.text = 'Creating icon';
+		const appIconName = appInfo.CFBundleIconFile.replace(/\.icns/, '');
+		composedIconPath = await composeIcon(path.join(appPath, 'Contents/Resources', `${appIconName}.icns`));
+	}
 
 	const minSystemVersion = (Object.prototype.hasOwnProperty.call(appInfo, 'LSMinimumSystemVersion') && appInfo.LSMinimumSystemVersion.length > 0) ? appInfo.LSMinimumSystemVersion.toString() : '10.11';
 	const minorVersion = Number(minSystemVersion.split('.')[1]) || 0;
@@ -143,9 +147,11 @@ async function init() {
 			ora.text = 'Adding Software License Agreement if needed';
 			await addLicenseAgreementIfNeeded(dmgPath, dmgFormat);
 
-			ora.text = 'Replacing DMG icon';
-			// `seticon`` is a native tool to change files icons (Source: https://github.com/sveinbjornt/osxiconutils)
-			await execa(path.join(__dirname, 'seticon'), [composedIconPath, dmgPath]);
+			if (hasAppIcon) {
+				ora.text = 'Replacing DMG icon';
+				// `seticon`` is a native tool to change files icons (Source: https://github.com/sveinbjornt/osxiconutils)
+				await execa(path.join(__dirname, 'seticon'), [composedIconPath, dmgPath]);
+			}
 
 			ora.text = 'Code signing DMG';
 			let identity;

fixtures/Fixture-no-icon.app/Contents/Info.plist

@@ -0,0 +1,54 @@
+<?xml version="1.0" encoding="UTF-8"?>
+<!DOCTYPE plist PUBLIC "-//Apple//DTD PLIST 1.0//EN" "http://www.apple.com/DTDs/PropertyList-1.0.dtd">
+<plist version="1.0">
+<dict>
+	<key>BuildMachineOSBuild</key>
+	<string>15G1217</string>
+	<key>CFBundleDevelopmentRegion</key>
+	<string>English</string>
+	<key>CFBundleExecutable</key>
+	<string>fixture</string>
+	<key>CFBundleIdentifier</key>
+	<string>com.sindresorhus.create-dmg.fixture</string>
+	<key>CFBundleInfoDictionaryVersion</key>
+	<string>6.0</string>
+	<key>CFBundleName</key>
+	<string>Fixture</string>
+	<key>LSApplicationCategoryType</key>
+	<string></string>
+	<key>CFBundlePackageType</key>
+	<string>APPL</string>
+	<key>CFBundleShortVersionString</key>
+	<string>0.0.1</string>
+	<key>CFBundleSignature</key>
+	<string>????</string>
+	<key>CFBundleSupportedPlatforms</key>
+	<array>
+		<string>MacOSX</string>
+	</array>
+	<key>CFBundleVersion</key>
+	<string>0.0.1</string>
+	<key>DTCompiler</key>
+	<string>com.apple.compilers.llvm.clang.1_0</string>
+	<key>DTPlatformBuild</key>
+	<string>8C38</string>
+	<key>DTPlatformVersion</key>
+	<string>GM</string>
+	<key>DTSDKBuild</key>
+	<string>16C58</string>
+	<key>DTSDKName</key>
+	<string>macosx10.12</string>
+	<key>DTXcode</key>
+	<string>0820</string>
+	<key>DTXcodeBuild</key>
+	<string>8C38</string>
+	<key>LSMinimumSystemVersion</key>
+	<string>10.11</string>
+	<key>NSMainNibFile</key>
+	<string>MainMenu</string>
+	<key>NSPrincipalClass</key>
+	<string>EventViewerApplication</string>
+	<key>NSSupportsSuddenTermination</key>
+	<string>YES</string>
+</dict>
+</plist>

fixtures/Fixture.app/Contents/PkgInfo

@@ -0,0 +1 @@
+APPL????

test.js

@@ -8,7 +8,7 @@ test('main', async t => {
 	const cwd = tempy.directory();
 
 	try {
-		await execa(path.join(__dirname, 'cli.js'), [path.join(__dirname, 'fixture.app')], {cwd});
+		await execa(path.join(__dirname, 'cli.js'), [path.join(__dirname, 'fixtures/Fixture.app')], {cwd});
 	} catch (error) {
 		// Silence code signing failure
 		if (!error.message.includes('Code signing failed')) {
@@ -23,7 +23,22 @@ test('binary plist', async t => {
 	const cwd = tempy.directory();
 
 	try {
-		await execa(path.join(__dirname, 'cli.js'), [path.join(__dirname, 'fixture-with-binary-plist.app')], {cwd});
+		await execa(path.join(__dirname, 'cli.js'), [path.join(__dirname, 'fixtures/Fixture-with-binary-plist.app')], {cwd});
+	} catch (error) {
+		// Silence code signing failure
+		if (!error.message.includes('Code signing failed')) {
+			throw error;
+		}
+	}
+
+	t.true(fs.existsSync(path.join(cwd, 'Fixture 0.0.1.dmg')));
+});
+
+test('app without icon', async t => {
+	const cwd = tempy.directory();
+
+	try {
+		await execa(path.join(__dirname, 'cli.js'), [path.join(__dirname, 'fixtures/Fixture-no-icon.app')], {cwd});
 	} catch (error) {
 		// Silence code signing failure
 		if (!error.message.includes('Code signing failed')) {