wip fake_api [nfc]: Add delay option to connection.prepare; TODO test

This allows simulating a request that takes some time to return
and consequently races with something else.

This is NFC because `Future.delayed(Duration.zero, f)` is exactly
equivalent to `Future(f)`.  (The docs aren't real clear on this;
but reading the implementations confirms they boil down to the
very same `Timer` constructor call, and then the docs do seem to be
trying to say that when read in light of that information.)

Author: gnprice

lib/widgets/action_sheet.dart

@@ -6,8 +6,6 @@ import 'package:share_plus/share_plus.dart';
 import '../api/exception.dart';
 import '../api/model/model.dart';
 import '../api/route/messages.dart';
-import '../model/internal_link.dart';
-import '../model/narrow.dart';
 import 'clipboard.dart';
 import 'compose_box.dart';
 import 'dialog.dart';
@@ -41,13 +39,12 @@ void showMessageActionSheet({required BuildContext context, required Message mes
       return Column(children: [
         if (!hasThumbsUpReactionVote) AddThumbsUpButton(message: message, messageListContext: context),
         StarButton(message: message, messageListContext: context),
+        ShareButton(message: message, messageListContext: context),
         if (isComposeBoxOffered) QuoteAndReplyButton(
           message: message,
           messageListContext: context,
         ),
         CopyMessageTextButton(message: message, messageListContext: context),
-        CopyMessageLinkButton(message: message, messageListContext: context),
-        ShareButton(message: message, messageListContext: context),
       ]);
     });
 }
@@ -167,6 +164,63 @@ class StarButton extends MessageActionSheetMenuItemButton {
   }
 }
 
+class ShareButton extends MessageActionSheetMenuItemButton {
+  ShareButton({
+    super.key,
+    required super.message,
+    required super.messageListContext,
+  });
+
+  @override IconData get icon => Icons.adaptive.share;
+
+  @override
+  String label(ZulipLocalizations zulipLocalizations) {
+    return zulipLocalizations.actionSheetOptionShare;
+  }
+
+  @override void onPressed(BuildContext context) async {
+    // Close the message action sheet; we're about to show the share
+    // sheet. (We could do this after the sharing Future settles
+    // with [ShareResultStatus.success], but on iOS I get impatient with
+    // how slowly our action sheet dismisses in that case.)
+    // TODO(#24): Fix iOS bug where this call causes the keyboard to
+    //   reopen (if it was open at the time of this
+    //   `showMessageActionSheet` call) and cover a large part of the
+    //   share sheet.
+    Navigator.of(context).pop();
+    final zulipLocalizations = ZulipLocalizations.of(messageListContext);
+
+    final rawContent = await fetchRawContentWithFeedback(
+      context: messageListContext,
+      messageId: message.id,
+      errorDialogTitle: zulipLocalizations.errorSharingFailed,
+    );
+
+    if (rawContent == null) return;
+
+    if (!messageListContext.mounted) return;
+
+    // TODO: to support iPads, we're asked to give a
+    //   `sharePositionOrigin` param, or risk crashing / hanging:
+    //     https://pub.dev/packages/share_plus#ipad
+    //   Perhaps a wart in the API; discussion:
+    //     https://github.com/zulip/zulip-flutter/pull/12#discussion_r1130146231
+    final result = await Share.share(rawContent);
+
+    switch (result.status) {
+      // The plugin isn't very helpful: "The status can not be determined".
+      // Until we learn otherwise, assume something wrong happened.
+      case ShareResultStatus.unavailable:
+        if (!messageListContext.mounted) return;
+        await showErrorDialog(context: messageListContext,
+          title: zulipLocalizations.errorSharingFailed);
+      case ShareResultStatus.success:
+      case ShareResultStatus.dismissed:
+        // nothing to do
+    }
+  }
+}
+
 /// Fetch and return the raw Markdown content for [messageId],
 /// showing an error dialog on failure.
 Future<String?> fetchRawContentWithFeedback({
@@ -307,96 +361,8 @@ class CopyMessageTextButton extends MessageActionSheetMenuItemButton {
 
     if (!messageListContext.mounted) return;
 
-    copyWithPopup(context: messageListContext,
+    copyWithPopup(context: context,
       successContent: Text(zulipLocalizations.successMessageTextCopied),
       data: ClipboardData(text: rawContent));
   }
 }
-
-class CopyMessageLinkButton extends MessageActionSheetMenuItemButton {
-  CopyMessageLinkButton({
-    super.key,
-    required super.message,
-    required super.messageListContext,
-  });
-
-  @override IconData get icon => Icons.link;
-
-  @override
-  String label(ZulipLocalizations zulipLocalizations) {
-    return zulipLocalizations.actionSheetOptionCopyMessageLink;
-  }
-
-  @override void onPressed(BuildContext context) {
-    Navigator.of(context).pop();
-    final zulipLocalizations = ZulipLocalizations.of(messageListContext);
-
-    final store = PerAccountStoreWidget.of(messageListContext);
-    final messageLink = narrowLink(
-      store,
-      SendableNarrow.ofMessage(message, selfUserId: store.selfUserId),
-      nearMessageId: message.id,
-    );
-
-    copyWithPopup(context: messageListContext,
-      successContent: Text(zulipLocalizations.successMessageLinkCopied),
-      data: ClipboardData(text: messageLink.toString()));
-  }
-}
-
-class ShareButton extends MessageActionSheetMenuItemButton {
-  ShareButton({
-    super.key,
-    required super.message,
-    required super.messageListContext,
-  });
-
-  @override IconData get icon => Icons.adaptive.share;
-
-  @override
-  String label(ZulipLocalizations zulipLocalizations) {
-    return zulipLocalizations.actionSheetOptionShare;
-  }
-
-  @override void onPressed(BuildContext context) async {
-    // Close the message action sheet; we're about to show the share
-    // sheet. (We could do this after the sharing Future settles
-    // with [ShareResultStatus.success], but on iOS I get impatient with
-    // how slowly our action sheet dismisses in that case.)
-    // TODO(#24): Fix iOS bug where this call causes the keyboard to
-    //   reopen (if it was open at the time of this
-    //   `showMessageActionSheet` call) and cover a large part of the
-    //   share sheet.
-    Navigator.of(context).pop();
-    final zulipLocalizations = ZulipLocalizations.of(messageListContext);
-
-    final rawContent = await fetchRawContentWithFeedback(
-      context: messageListContext,
-      messageId: message.id,
-      errorDialogTitle: zulipLocalizations.errorSharingFailed,
-    );
-
-    if (rawContent == null) return;
-
-    if (!messageListContext.mounted) return;
-
-    // TODO: to support iPads, we're asked to give a
-    //   `sharePositionOrigin` param, or risk crashing / hanging:
-    //     https://pub.dev/packages/share_plus#ipad
-    //   Perhaps a wart in the API; discussion:
-    //     https://github.com/zulip/zulip-flutter/pull/12#discussion_r1130146231
-    final result = await Share.share(rawContent);
-
-    switch (result.status) {
-      // The plugin isn't very helpful: "The status can not be determined".
-      // Until we learn otherwise, assume something wrong happened.
-      case ShareResultStatus.unavailable:
-        if (!messageListContext.mounted) return;
-        await showErrorDialog(context: messageListContext,
-          title: zulipLocalizations.errorSharingFailed);
-      case ShareResultStatus.success:
-      case ShareResultStatus.dismissed:
-        // nothing to do
-    }
-  }
-}

test/api/fake_api.dart

@@ -8,19 +8,22 @@ import 'package:zulip/model/store.dart';
 import '../example_data.dart' as eg;
 
 sealed class _PreparedResponse {
+  final Duration delay;
+
+  _PreparedResponse({this.delay = Duration.zero});
 }
 
 class _PreparedException extends _PreparedResponse {
   final Object exception;
 
-  _PreparedException({required this.exception});
+  _PreparedException({super.delay, required this.exception});
 }
 
 class _PreparedSuccess extends _PreparedResponse {
   final int httpStatus;
   final List<int> bytes;
 
-  _PreparedSuccess({required this.httpStatus, required this.bytes});
+  _PreparedSuccess({super.delay, required this.httpStatus, required this.bytes});
 }
 
 /// An [http.Client] that accepts and replays canned responses, for testing.
@@ -53,12 +56,13 @@ class FakeHttpClient extends http.BaseClient {
     int? httpStatus,
     Map<String, dynamic>? json,
     String? body,
+    Duration delay = Duration.zero,
   }) {
     assert(_nextResponse == null,
       'FakeApiConnection.prepare was called while already expecting a request');
     if (exception != null) {
       assert(httpStatus == null && json == null && body == null);
-      _nextResponse = _PreparedException(exception: exception);
+      _nextResponse = _PreparedException(exception: exception, delay: delay);
     } else {
       assert((json == null) || (body == null));
       final String resolvedBody = switch ((body, json)) {
@@ -69,6 +73,7 @@ class FakeHttpClient extends http.BaseClient {
       _nextResponse = _PreparedSuccess(
         httpStatus: httpStatus ?? 200,
         bytes: utf8.encode(resolvedBody),
+        delay: delay,
       );
     }
   }
@@ -89,14 +94,16 @@ class FakeHttpClient extends http.BaseClient {
     final response = _nextResponse!;
     _nextResponse = null;
 
+    final http.StreamedResponse Function() computation;
     switch (response) {
       case _PreparedException(:var exception):
-        return Future(() => throw exception);
+        computation = () => throw exception;
       case _PreparedSuccess(:var bytes, :var httpStatus):
         final byteStream = http.ByteStream.fromBytes(bytes);
-        return Future(() => http.StreamedResponse(
-          byteStream, httpStatus, request: request));
+        computation = () => http.StreamedResponse(
+          byteStream, httpStatus, request: request);
     }
+    return Future.delayed(response.delay, computation);
   }
 }
 
@@ -203,13 +210,20 @@ class FakeApiConnection extends ApiConnection {
   ///
   /// If `exception` is non-null, then `httpStatus`, `body`, and `json` must
   /// all be null, and the next request will throw the given exception.
+  ///
+  /// In either case, the next request will complete a duration of `delay`
+  /// after being started.
   void prepare({
     Object? exception,
     int? httpStatus,
     Map<String, dynamic>? json,
     String? body,
+    Duration delay = Duration.zero,
   }) {
     client.prepare(
-      exception: exception, httpStatus: httpStatus, json: json, body: body);
+      exception: exception,
+      httpStatus: httpStatus, json: json, body: body,
+      delay: delay,
+    );
   }
 }