feat: support smol:// QR sharing, deep links and in-dialog scanning

test/link_test.dart

@@ -0,0 +1,45 @@
+// Deep links: only smol:// URIs react, and only the native parser's verdict
+// decides that — the format rules stay in fumi, not a Dart copy of them.
+
+import "package:flutter_test/flutter_test.dart";
+
+import "package:smol_mail/smol/link.dart";
+
+const key = "lm2gqd7e5q67xq3isc5hx6jfj2q7a7xvq4l7trctxipudujovmgq";
+
+void main() {
+  test("self-certifying URI carries its key", () {
+    final link = parseSmolLink("smol://alice@example.org/$key");
+    expect(link, isNotNull);
+    expect(link!.address.identity, key);
+    expect(link.address.user, "alice");
+    expect(link.address.host, "example.org");
+    expect(link.address.port, 1961);
+    expect(link.source, "smol://alice@example.org/$key");
+  });
+
+  test("a non-default port is kept", () {
+    final link = parseSmolLink("smol://alice@example.org:1962/$key");
+    expect(link!.address.port, 1962);
+  });
+
+  test("a smol:// URI without its key is not a link", () {
+    // fumi rejects this form, so a truncated scan acts on nothing rather
+    // than importing a key the sender never signed into.
+    expect(parseSmolLink("smol://alice@example.org"), isNull);
+  });
+
+  test("other schemes are not ours", () {
+    expect(parseSmolLink("https://example.org/a"), isNull);
+    expect(parseSmolLink("mailto:alice@example.org"), isNull);
+  });
+
+  test("scheme-less addresses are not deep links", () {
+    expect(parseSmolLink("alice@example.org"), isNull);
+  });
+
+  test("a smol:// URI the parser rejects is ignored", () {
+    expect(parseSmolLink("smol://not a uri"), isNull);
+    expect(parseSmolLink("smol://alice@example.org/tooshort"), isNull);
+  });
+}

test/qr_sheet_test.dart

@@ -0,0 +1,28 @@
+import "package:flutter/material.dart";
+import "package:flutter_test/flutter_test.dart";
+import "package:qr_flutter/qr_flutter.dart";
+
+import "package:smol_mail/presentation/theme/theme.dart";
+import "package:smol_mail/presentation/widgets/qr_code_sheet.dart";
+
+void main() {
+  testWidgets("the sheet renders the payload as a scannable QR code",
+      (tester) async {
+    const payload = "smol://alice@example.org/lm2gqd7e5q67xq3isc5hx6jfj2q7a7xvq4l7trctxipudujovmgq";
+    await tester.pumpWidget(
+      MaterialApp(
+        theme: appThemeLight,
+        home: Builder(
+          builder: (context) => TextButton(
+            onPressed: () => showQrCodeSheet(context, payload),
+            child: const Text("show"),
+          ),
+        ),
+      ),
+    );
+    await tester.tap(find.text("show"));
+    await tester.pumpAndSettle();
+    expect(find.byType(QrImageView), findsOneWidget);
+    expect(find.text(payload), findsOneWidget);
+  });
+}

test/widget_test.dart

@@ -1,5 +1,6 @@
 import "dart:io";
 
+import "package:app_links_platform_interface/app_links_platform_interface.dart";
 import "package:flutter_riverpod/flutter_riverpod.dart";
 import "package:flutter_test/flutter_test.dart";
 import "package:hive_flutter/hive_flutter.dart";
@@ -10,11 +11,22 @@ import "package:smol_mail/smol/store.dart";
 
 late final SmolStore store;
 
+// AppWidget subscribes to app_links on boot; in the test shell there is no
+// platform plugin to talk to, so the subscription points at this no-op.
+class _NoopAppLinks extends AppLinksPlatform {
+  @override
+  Future<Uri?> getInitialLink() async => null;
+
+  @override
+  Stream<Uri> get uriLinkStream => const Stream.empty();
+}
+
 void main() {
   // Hive's box opening is real file IO, which never completes inside a
   // testWidgets fake-async zone — so it happens here, outside one.
   setUpAll(() async {
     TestWidgetsFlutterBinding.ensureInitialized();
+    AppLinksPlatform.instance = _NoopAppLinks();
     final dir = await Directory.systemTemp.createTemp("smol-widget-test");
     Hive.init(dir.path);
     store = await SmolStore.open(dbPath: "${dir.path}/widget.db");