improve error handling

webpack · Jan 21, 2021 · 988cf8d · 988cf8d
1 parent a1515fa
commit 988cf8d
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Showing 5 changed files with 87 additions and 45 deletions.
diff --git a/hot/lazy-compilation-node.js b/hot/lazy-compilation-node.js
@@ -9,20 +9,28 @@ if (!module.hot) {
 }
 
 var urlBase = decodeURIComponent(__resourceQuery.slice(1));
-exports.keepAlive = function (key) {
+exports.keepAlive = function (options) {
+	var data = options.data;
+	var onError = options.onError;
 	var response;
-	require("http")
-		.request(
-			urlBase + key,
-			{
-				agent: false,
-				headers: { accept: "text/event-stream" }
-			},
-			function (res) {
-				response = res;
-			}
-		)
-		.end();
+	var request = require("http").request(
+		urlBase + data,
+		{
+			agent: false,
+			headers: { accept: "text/event-stream" }
+		},
+		function (res) {
+			response = res;
+			response.on("error", errorHandler);
+		}
+	);
+	function errorHandler(err) {
+		err.message =
+			"Problem communicating active modules to the server: " + err.message;
+		onError(err);
+	}
+	request.on("error", errorHandler);
+	request.end();
 	return function () {
 		response.destroy();
 	};

diff --git a/hot/lazy-compilation-web.js b/hot/lazy-compilation-web.js
@@ -11,29 +11,56 @@ if (typeof EventSource !== "function" || !module.hot) {
 var urlBase = decodeURIComponent(__resourceQuery.slice(1));
 var activeEventSource;
 var activeKeys = new Map();
+var errorHandlers = new Set();
 
 var updateEventSource = function updateEventSource() {
 	if (activeEventSource) activeEventSource.close();
-	activeEventSource = new EventSource(
-		urlBase + Array.from(activeKeys.keys()).join("@")
-	);
+	if (activeKeys.size) {
+		activeEventSource = new EventSource(
+			urlBase + Array.from(activeKeys.keys()).join("@")
+		);
+		activeEventSource.onerror = function (event) {
+			errorHandlers.forEach(function (onError) {
+				onError(
+					new Error(
+						"Problem communicating active modules to the server: " +
+							event.message +
+							" " +
+							event.filename +
+							":" +
+							event.lineno +
+							":" +
+							event.colno +
+							" " +
+							event.error
+					)
+				);
+			});
+		};
+	} else {
+		activeEventSource = undefined;
+	}
 };
 
-exports.keepAlive = function (key) {
-	var value = activeKeys.get(key) || 0;
-	activeKeys.set(key, value + 1);
+exports.keepAlive = function (options) {
+	var data = options.data;
+	var onError = options.onError;
+	errorHandlers.add(onError);
+	var value = activeKeys.get(data) || 0;
+	activeKeys.set(data, value + 1);
 	if (value === 0) {
 		updateEventSource();
 	}
 
 	return function () {
+		errorHandlers.delete(onError);
 		setTimeout(function () {
-			var value = activeKeys.get(key);
+			var value = activeKeys.get(data);
 			if (value === 1) {
-				activeKeys.delete(key);
+				activeKeys.delete(data);
 				updateEventSource();
 			} else {
-				activeKeys.set(key, value - 1);
+				activeKeys.set(data, value - 1);
 			}
 		}, 1000);
 	};

diff --git a/lib/hmr/LazyCompilationPlugin.js b/lib/hmr/LazyCompilationPlugin.js
@@ -180,9 +180,9 @@ class LazyCompilationProxyModule extends Module {
 				runtimeRequirements
 			})}`,
 			`var data = ${JSON.stringify(this.data)};`,
-			`var dispose = client.keepAlive(data, ${JSON.stringify(
+			`var dispose = client.keepAlive({ data, active: ${JSON.stringify(
 				!!block
-			)}, module);`
+			)}, module, onError });`
 		]);
 		let source;
 		if (block) {
@@ -203,18 +203,21 @@ class LazyCompilationProxyModule extends Module {
 					message: "import()",
 					runtimeRequirements
 				})};`,
-				"if (module.hot.data && module.hot.data.resolveSelf) module.hot.data.resolveSelf(module.exports);"
+				"if (module.hot.data && module.hot.data.resolveSelf) module.hot.data.resolveSelf(module.exports);",
+				"function onError() { /* ignore */ }",
+				keepActive
 			]);
 		} else {
 			source = Template.asString([
 				"module.hot.accept();",
-				"var resolveSelf;",
-				`module.exports = new Promise(function(resolve) { resolveSelf = resolve; });`,
+				"var resolveSelf, onError;",
+				`module.exports = new Promise(function(resolve, reject) { resolveSelf = resolve; onError = reject; });`,
 				"if (module.hot.data && module.hot.data.resolveSelf) module.hot.data.resolveSelf(module.exports);",
-				"module.hot.dispose(function(data) { data.resolveSelf = resolveSelf; dispose(data); });"
+				"module.hot.dispose(function(data) { data.resolveSelf = resolveSelf; dispose(data); });",
+				keepActive
 			]);
 		}
-		sources.set("javascript", new RawSource(keepActive + "\n\n" + source));
+		sources.set("javascript", new RawSource(source));
 		return {
 			sources,
 			runtimeRequirements

diff --git a/test/helpers/EventSourceForNode.js b/test/helpers/EventSourceForNode.js
@@ -8,21 +8,23 @@
 module.exports = class EventSource {
 	constructor(url) {
 		this.response = undefined;
-		require("http")
-			.request(
-				url,
-				{
-					agent: false,
-					headers: { accept: "text/event-stream" }
-				},
-				res => {
-					this.response = res;
-					res.on("error", err => {
-						if (this.onerror) this.onerror(err);
-					});
-				}
-			)
-			.end();
+		const request = require("http").request(
+			url,
+			{
+				agent: false,
+				headers: { accept: "text/event-stream" }
+			},
+			res => {
+				this.response = res;
+				res.on("error", err => {
+					if (this.onerror) this.onerror(err);
+				});
+			}
+		);
+		request.on("error", err => {
+			if (this.onerror) this.onerror({ message: err });
+		});
+		request.end();
 	}
 
 	close() {

diff --git a/test/hotCases/lazy-compilation/simple/index.js b/test/hotCases/lazy-compilation/simple/index.js
@@ -8,7 +8,9 @@ it("should compile to lazy imported module", done => {
 			require("../../update")(done, true, () => {
 				promise.then(result => {
 					expect(result).toHaveProperty("default", 42);
-					done();
+					setTimeout(() => {
+						done();
+					}, 1000);
 				}, done);
 			})
 		);