Update Babel protocol

Author: novemberborn

lib/babel-manager.js

@@ -7,10 +7,10 @@ module.exports = ({projectDir}) => {
 
 	let fatal;
 	const provider = makeProvider({
-		negotiateProtocol(identifiers) {
-			// TODO: Settle on a identifier before releasing AVA@3; fix error message.
-			if (!identifiers.includes('1')) {
-				fatal = new Error('TODO: Throw error when @ava/babel does not negotiate the expected protocol');
+		negotiateProtocol(identifiers, {version}) {
+			// TODO: Remove `-pre` before releasing AVA@3.
+			if (!identifiers.includes('ava-3-pre')) {
+				fatal = new Error(`This version of AVA (${ava.version}) is not compatible with@ava/babel@${version}`);
 				return null;
 			}
 
@@ -19,7 +19,7 @@ module.exports = ({projectDir}) => {
 				async findFiles({extensions, patterns}) {
 					return globs.findFiles({cwd: projectDir, extensions, filePatterns: patterns});
 				},
-				identifier: '1',
+				identifier: 'ava-3-pre',
 				normalizeGlobPatterns: globs.normalizePatterns,
 				projectDir
 			};

package-lock.json

@@ -111,7 +111,7 @@
 		"yargs": "^15.1.0"
 	},
 	"devDependencies": {
-		"@ava/babel": "^0.4.0",
+		"@ava/babel": "^0.5.0",
 		"@types/node": "^10.17.13",
 		"delay": "^4.3.0",
 		"esm": "^3.2.25",