fix: detect bootloader when short chunks are received

packages/serial/src/ZWaveSerialPortBase.ts

@@ -158,7 +158,9 @@ export class ZWaveSerialPortBase extends PassThrough {
 			if (this.mode == undefined) {
 				// If we haven't figured out the startup mode yet,
 				// inspect the chunk to see if it contains the bootloader preamble
-				const str = (data as Buffer).toString("ascii").trim();
+				const str = (data as Buffer).toString("ascii")
+					// like .trim(), but including null bytes
+					.replaceAll(/^[\s\0]+|[\s\0]+$/g, "");
 				this.mode = str.startsWith(bootloaderMenuPreamble)
 					? ZWaveSerialMode.Bootloader
 					: ZWaveSerialMode.SerialAPI;

packages/serial/src/parsers/BootloaderParsers.ts

@@ -79,8 +79,9 @@ export class BootloaderScreenParser extends Transform {
 			const screen = this.receiveBuffer.slice(0, nulCharIndex).trim();
 			this.receiveBuffer = this.receiveBuffer.slice(nulCharIndex + 1);
 
-			this.logger?.bootloaderScreen(screen);
+			if (screen === "") continue;
 
+			this.logger?.bootloaderScreen(screen);
 			this.push(screen);
 		}
 
@@ -107,7 +108,9 @@ export class BootloaderScreenParser extends Transform {
 	}
 }
 
-export const bootloaderMenuPreamble = "Gecko Bootloader";
+// Sometimes the first chunk of the bootloader screen is relatively short,
+// so we consider the following enough to detect the bootloader menu:
+export const bootloaderMenuPreamble = "Gecko Boo";
 const preambleRegex = /^Gecko Bootloader v(?<version>\d+\.\d+\.\d+)/;
 const menuSuffix = "BL >";
 const optionsRegex = /^(?<num>\d+)\. (?<option>.+)/gm;

packages/testing/src/MockController.ts

@@ -40,7 +40,14 @@ export class MockController {
 		this.serial = options.serial;
 		// Pipe the serial data through a parser, so we get complete message buffers or headers out the other end
 		this.serialParser = new SerialAPIParser();
-		this.serial.on("write", (data) => {
+		this.serial.on("write", async (data) => {
+			// Execute hooks for inspecting the raw data first
+			for (const behavior of this.behaviors) {
+				if (await behavior.onHostData?.(this.host, this, data)) {
+					return;
+				}
+			}
+			// Then parse the data normally
 			this.serialParser.write(data);
 		});
 		this.serialParser.on("data", (data) => this.serialOnData(data));
@@ -486,6 +493,15 @@ export class MockController {
 }
 
 export interface MockControllerBehavior {
+	/**
+	 * Can be used to inspect raw data received from the host before it is processed by the serial parser and the mock controller.
+	 * Return `true` to indicate that the data has been handled and should not be processed further.
+	 */
+	onHostData?: (
+		host: ZWaveHost,
+		controller: MockController,
+		data: Buffer,
+	) => Promise<boolean | undefined> | boolean | undefined;
 	/** Gets called when a message from the host is received. Return `true` to indicate that the message has been handled. */
 	onHostMessage?: (
 		host: ZWaveHost,

packages/zwave-js/src/lib/test/driver/bootloaderDetection.test.ts

@@ -0,0 +1,45 @@
+import { type MockControllerBehavior } from "@zwave-js/testing";
+import { wait } from "alcalzone-shared/async";
+import { integrationTest } from "../integrationTestSuite";
+
+integrationTest(
+	"The bootloader is detected when received in smaller chunks",
+	{
+		// Reproduction for issue #7316
+		// debug: true,
+
+		additionalDriverOptions: {
+			allowBootloaderOnly: true,
+		},
+
+		async customSetup(driver, mockController, mockNode) {
+			const sendBootloaderMessageInChunks: MockControllerBehavior = {
+				async onHostData(host, self, ctrl) {
+					// if (
+					// 	ctrl.length === 1
+					// 	&& (ctrl[0] === MessageHeaders.NAK || ctrl[0] === 0x32)
+					// ) {
+					self.serial.emitData(
+						Buffer.from("\0\r\nGecko Bootloa", "ascii"),
+					);
+					await wait(20);
+					self.serial.emitData(Buffer.from(
+						`der v2.05.01
+1. upload gbl
+2. run
+3. ebl info
+BL >\0`,
+						"ascii",
+					));
+					return true;
+					// }
+				},
+			};
+			mockController.defineBehavior(sendBootloaderMessageInChunks);
+		},
+
+		testBody: async (t, driver, node, mockController, mockNode) => {
+			t.true(driver.isInBootloader());
+		},
+	},
+);

packages/zwave-js/src/lib/test/integrationTestSuite.ts

@@ -144,6 +144,12 @@ function suite(
 				}
 			});
 
+			if (options.additionalDriverOptions?.allowBootloaderOnly) {
+				driver.once("bootloader ready", () => {
+					process.nextTick(resolve);
+				});
+			}
+
 			continueStartup();
 		});
 	}