compose [nfc]: Take a URL string at inlineLink, rather than a Uri object

This way this function is a more faithful wrapper of constructing
the actual Markdown syntax.  The Markdown will have a URL string,
after all, so it's for the best to put this function's caller in
control of exactly what string that is.

Author: gnprice

lib/model/compose.dart

@@ -188,8 +188,8 @@ String wildcardMention(WildcardMentionOption wildcardOption, {
 /// result may be surprising.
 ///
 /// The part between "(" and ")" is just a "link destination" (no "link title").
-/// That destination is simply the stringified [destination], if provided.
-/// If that has parentheses in it, the result may be surprising.
+/// That destination is the string [destination], if provided.
+/// If [destination] has parentheses in it, the result may be surprising.
 // TODO: Try harder to guarantee output that creates an inline link,
 //   and in particular, the intended one. We could help with this by escaping
 //   square brackets, perhaps with HTML character references:
@@ -199,8 +199,8 @@ String wildcardMention(WildcardMentionOption wildcardOption, {
 //   > Backtick code spans, autolinks, and raw HTML tags bind more tightly
 //   > than the brackets in link text. Thus, for example, [foo`]` could not be
 //   > a link text, since the second ] is part of a code span.
-String inlineLink(String visibleText, Uri? destination) {
-  return '[$visibleText](${destination?.toString() ?? ''})';
+String inlineLink(String visibleText, String? destination) {
+  return '[$visibleText](${destination ?? ''})';
 }
 
 /// What we show while fetching the target message's raw Markdown.
@@ -213,7 +213,7 @@ String quoteAndReplyPlaceholder(
     SendableNarrow.ofMessage(message, selfUserId: store.selfUserId),
     nearMessageId: message.id);
   return '${userMentionFromMessage(message, silent: true, users: store)} '
-    '${inlineLink('said', url)}: ' // TODO(#1285)
+    '${inlineLink('said', url.toString())}: ' // TODO(#1285)
     '*${zulipLocalizations.composeBoxLoadingMessage(message.id)}*\n';
 }
 
@@ -237,6 +237,6 @@ String quoteAndReply(PerAccountStore store, {
   // and the extra noise won't much matter with the already probably-long
   // message link in there too.
   return '${userMentionFromMessage(message, silent: true, users: store)} '
-    '${inlineLink('said', url)}:\n' // TODO(#1285)
+    '${inlineLink('said', url.toString())}:\n' // TODO(#1285)
     '${wrapWithBacktickFence(content: rawContent, infoString: 'quote')}';
 }

lib/widgets/compose_box.dart

@@ -372,7 +372,7 @@ class ComposeContentController extends ComposeController<ContentValidationError>
 
     value = value.replaced(
       replacementRange,
-      url == null ? '' : inlineLink(filename, url));
+      url == null ? '' : inlineLink(filename, url.toString()));
     _uploads.remove(tag);
     notifyListeners(); // _uploads change could affect validationErrors
   }

test/model/compose_test.dart

@@ -319,9 +319,9 @@ hello
   });
 
   test('inlineLink', () {
-    check(inlineLink('CZO', Uri.parse('https://chat.zulip.org/'))).equals('[CZO](https://chat.zulip.org/)');
+    check(inlineLink('CZO', 'https://chat.zulip.org/')).equals('[CZO](https://chat.zulip.org/)');
     check(inlineLink('Uploading file.txt…', null)).equals('[Uploading file.txt…]()');
-    check(inlineLink('IMG_2488.png', Uri.parse('/user_uploads/2/a3/ucEMyjxk90mcNF0y9rmW5XKO/IMG_2488.png')))
+    check(inlineLink('IMG_2488.png', '/user_uploads/2/a3/ucEMyjxk90mcNF0y9rmW5XKO/IMG_2488.png'))
       .equals('[IMG_2488.png](/user_uploads/2/a3/ucEMyjxk90mcNF0y9rmW5XKO/IMG_2488.png)');
   });