fix: JSON stringify failure details for CSV (#613)

src/cli.ts

@@ -174,10 +174,11 @@ async function main() {
 		if (format === Format.CSV) {
 			const showIt = shouldShowResult(link, verbosity);
 			if (showIt) {
+				const failureDetails = link.failureDetails
+					? JSON.stringify(link.failureDetails, null, 2)
+					: '';
 				console.log(
-					`"${link.url}",${link.status},${link.state},"${link.parent || ''}","${
-						link.failureDetails?.toString() || ''
-					}"`,
+					`"${link.url}",${link.status},${link.state},"${link.parent || ''}","${failureDetails}"`,
 				);
 			}
 		}

test/fixtures/localbroke/README.md

@@ -0,0 +1,3 @@
+# Locally broken
+
+This is a [link](/test) to a page that doesn't exist.

test/test.cli.ts

@@ -99,6 +99,20 @@ describe('cli', function () {
 		assert.match(response.stdout, /README.md",200,OK,/);
 	});
 
+	it('should serialize errors with CSV and verbose output', async () => {
+		const response = await execa(node, [
+			linkinator,
+			'--format',
+			'csv',
+			'--verbosity',
+			'DEBUG',
+			'test/fixtures/localbroke/README.md',
+		]);
+		// This is a very lazy way of trying to recognize the JSON we expect
+		// in CSV without using a CSV parser.
+		assert.match(response.stdout, /statusText": "Not Found"/);
+	});
+
 	it('should provide JSON if asked nicely', async () => {
 		const response = await execa(node, [
 			linkinator,