fix(scan): allow slower SANE network discovery

agents/fedeo-device-agent/src/scan/sane.ts

@@ -20,7 +20,9 @@ export const hasSane = () => commandExists("scanimage")
 
 export const listScanners = async () => {
     if (!await hasSane()) return []
-    const result = await runCommand("scanimage", ["-L"], { timeoutMs: 10_000 })
+    // SANE also probes network backends; these can take more than ten seconds
+    // even when the USB scanner is already available.
+    const result = await runCommand("scanimage", ["-L"], { timeoutMs: 30_000 })
     if (result.code !== 0) return []
     return result.stdout.split(/\r?\n/)
         .map((line) => line.trim().match(/^device `([^']+)'/)?.[1])

agents/fedeo-device-agent/tests/scan.test.ts

@@ -3,16 +3,21 @@ import test, { TestContext } from "node:test"
 import os from "node:os"
 import path from "node:path"
 import { chmod, mkdtemp, readFile, readdir, rm, writeFile } from "node:fs/promises"
-import { runScan } from "../src/scan/sane.js"
+import { listScanners, runScan } from "../src/scan/sane.js"
 import { commandExists, runCommand } from "../src/commands.js"
 import { AgentConfig, ScanJob } from "../src/types.js"
 
 const fakeScanner = `#!/usr/bin/env python3
-import json, os, sys
+import json, os, sys, time
 from pathlib import Path
 from PIL import Image
 args = sys.argv[1:]
 Path(os.environ['SCAN_TEST_CALL']).write_text(json.dumps(args))
+if args == ['-L']:
+    time.sleep(float(os.environ.get('SCAN_TEST_DISCOVERY_DELAY', '0')))
+    print("device " + chr(96) + "fujitsu:ScanSnap iX1600:test' is a FUJITSU scanner")
+    print("device " + chr(96) + "airscan:test' is a network scanner")
+    sys.exit(int(os.environ.get('SCAN_TEST_EXIT', '0')))
 batch = next((arg.split('=', 1)[1] for arg in args if arg.startswith('--batch=')), None)
 single = args[args.index('--output-file') + 1] if '--output-file' in args else None
 count = int(os.environ.get('SCAN_TEST_PAGES', '4')) if batch else 1
@@ -52,6 +57,18 @@ const setup = async (t: TestContext) => {
     return { config, job, dir, args: async () => JSON.parse(await readFile(process.env.SCAN_TEST_CALL!, "utf8")) as string[] }
 }
 
+test("scanner discovery waits for network probes beyond the former ten-second limit", async (t) => {
+    await setup(t)
+    process.env.SCAN_TEST_DISCOVERY_DELAY = "10.2"
+    assert.deepEqual(await listScanners(), ["fujitsu:ScanSnap iX1600:test", "airscan:test"])
+})
+
+test("failed scanner discovery does not advertise devices from an unsuccessful command", async (t) => {
+    await setup(t)
+    process.env.SCAN_TEST_EXIT = "1"
+    assert.deepEqual(await listScanners(), [])
+})
+
 test("duplex batch saves all pages as PDF, accepts NO_DOCS and passes A4 geometry", async (t) => {
     const { config, job, args } = await setup(t)
     process.env.SCAN_TEST_EMPTY_FINAL = "1"