From 295aaa393fda8ecce110c38880a00466b9320e63 Mon Sep 17 00:00:00 2001
From: Andrey Kuzmin <hi@unsoundscapes.com>
Date: Wed, 31 Jan 2024 10:20:50 +0100
Subject: [PATCH] Round progress percentage according to the spec (#1413)

Round progress to match the spec
---
 client-node-tests/src/integration.test.ts   | 34 +++++++++++++++++++++
 client-node-tests/src/servers/testServer.ts |  8 +++++
 server/src/common/progress.ts               | 10 ++++--
 3 files changed, 50 insertions(+), 2 deletions(-)

diff --git a/client-node-tests/src/integration.test.ts b/client-node-tests/src/integration.test.ts
index dd89f86f..70356e7a 100644
--- a/client-node-tests/src/integration.test.ts
+++ b/client-node-tests/src/integration.test.ts
@@ -566,6 +566,40 @@ suite('Client integration', () => {
 		);
 	});
 
+	test('Progress percentage is an integer', async () => {
+		const progressToken = 'TEST-PROGRESS-PERCENTAGE';
+		const percentages: Array<number | undefined> = [];
+		let currentProgressResolver: (value: unknown) => void | undefined;
+
+		// Set up middleware that calls the current resolve function when it gets its 'end' progress event.
+		middleware.handleWorkDoneProgress = (token: lsclient.ProgressToken, params: lsclient.WorkDoneProgressBegin | lsclient.WorkDoneProgressReport | lsclient.WorkDoneProgressEnd, next) => {
+			if (token === progressToken) {
+				const percentage = params.kind === 'report' || params.kind === 'begin' ? params.percentage : undefined;
+				percentages.push(percentage);
+
+				if (params.kind === 'end') {
+					setImmediate(currentProgressResolver);
+				}
+			}
+			return next(token, params);
+		};
+
+		// Trigger a progress event.
+		await new Promise<unknown>((resolve) => {
+			currentProgressResolver = resolve;
+			void client.sendRequest(
+				new lsclient.ProtocolRequestType<any, null, never, any, any>('testing/sendSampleProgress'),
+				{},
+				tokenSource.token,
+			);
+		});
+
+		middleware.handleWorkDoneProgress = undefined;
+
+		// Ensure percentages are rounded according to the spec
+		assert.deepStrictEqual(percentages, [0, 50, undefined]);
+	});
+
 	test('Document Formatting', async () => {
 		const provider = client.getFeature(lsclient.DocumentFormattingRequest.method).getProvider(document);
 		isDefined(provider);
diff --git a/client-node-tests/src/servers/testServer.ts b/client-node-tests/src/servers/testServer.ts
index bd7226df..f0302609 100644
--- a/client-node-tests/src/servers/testServer.ts
+++ b/client-node-tests/src/servers/testServer.ts
@@ -530,6 +530,14 @@ connection.onRequest(
 		void connection.sendProgress(WorkDoneProgress.type, progressToken, { kind: 'begin', title: 'Test Progress' });
 		void connection.sendProgress(WorkDoneProgress.type, progressToken, { kind: 'report', percentage: 50, message: 'Halfway!' });
 		void connection.sendProgress(WorkDoneProgress.type, progressToken, { kind: 'end', message: 'Completed!' });
+
+		// According to the spec, the reported percentage has to be an integer.
+		// Because JS doesn't have integer support, we have rounding code in place.
+		const progressToken2 = 'TEST-PROGRESS-PERCENTAGE';
+		const progress = connection.window.attachWorkDoneProgress(progressToken2);
+		progress.begin('Test Progress', 0.1);
+		progress.report(49.9, 'Halfway!');
+		progress.done();
 	},
 );
 
diff --git a/server/src/common/progress.ts b/server/src/common/progress.ts
index 8f1ab5a7..4abff060 100644
--- a/server/src/common/progress.ts
+++ b/server/src/common/progress.ts
@@ -47,10 +47,14 @@ class WorkDoneProgressReporterImpl implements WorkDoneProgressReporter {
 		const param: WorkDoneProgressBegin = {
 			kind: 'begin',
 			title,
-			percentage,
 			message,
 			cancellable
 		};
+		if (typeof percentage === 'number') {
+			// Round to the nearest integer, because the percentage
+			// is a uinteger according to the specification
+			param.percentage = Math.round(percentage);
+		}
 		this._connection.sendProgress(WorkDoneProgress.type, this._token, param);
 	}
 
@@ -59,7 +63,9 @@ class WorkDoneProgressReporterImpl implements WorkDoneProgressReporter {
 			kind: 'report'
 		};
 		if (typeof arg0 === 'number') {
-			param.percentage = arg0;
+			// Round to the nearest integer, because the percentage
+			// is a uinteger according to the specification
+			param.percentage = Math.round(arg0);
 			if (arg1 !== undefined) {
 				param.message = arg1;
 			}