Add test for undocumented declaration (// comment)

packages/docgen/src/get-jsdoc-from-token.js

@@ -11,7 +11,7 @@ const getLeadingComments = require( './get-leading-comments' );
 module.exports = function( token ) {
 	let jsdoc;
 	const comments = getLeadingComments( token );
-	if ( comments ) {
+	if ( comments && comments.startsWith( '*\n' ) ) {
 		jsdoc = doctrine.parse( comments, { unwrap: true, recoverable: true } );
 	}
 	return jsdoc;

packages/docgen/tests/fixtures/default-undocumented-oneliner.js

@@ -0,0 +1,2 @@
+// This comment should be ignored
+export default function() { }

packages/docgen/tests/fixtures/default-undocumented-oneliner.json

@@ -0,0 +1,45 @@
+{
+	"type": "ExportDefaultDeclaration",
+	"start": 34,
+	"end": 63,
+	"range": [
+		34,
+		63
+	],
+	"declaration": {
+		"type": "FunctionDeclaration",
+		"start": 49,
+		"end": 63,
+		"range": [
+			49,
+			63
+		],
+		"id": null,
+		"generator": false,
+		"expression": false,
+		"async": false,
+		"params": [],
+		"body": {
+			"type": "BlockStatement",
+			"start": 60,
+			"end": 63,
+			"range": [
+				60,
+				63
+			],
+			"body": []
+		}
+	},
+	"leadingComments": [
+		{
+			"type": "Line",
+			"value": " This comment should be ignored",
+			"start": 0,
+			"end": 33,
+			"range": [
+				0,
+				33
+			]
+		}
+	]
+}

packages/docgen/tests/test-get-intermediate-representation.js

@@ -24,6 +24,15 @@ test( 'IR - undocumented', function( t ) {
 		description: 'Undocumented declaration.',
 		tags: [],
 	} ] );
+	const tokenOneliner = fs.readFileSync(
+		path.join( __dirname, './fixtures/default-undocumented-oneliner.json' ),
+		'utf-8'
+	);
+	t.deepEqual( getIntermediateRepresentation( JSON.parse( tokenOneliner ) ), [ {
+		name: 'default',
+		description: 'Undocumented declaration.',
+		tags: [],
+	} ] );
 	t.end();
 } );