cob: improve Comment generics

`Infallible` is a more appropriate type in comparsion to `()` for
comments that do not require a `CodeLocation`.

That is because if the type for `location` is `Option<()>`, this means
that `Some(())` can be constructed, however, we never intend to
construct that variant. On the other hand, `Infallible` can never be
constructed, and so, only `None` can be used.

This requires updates to some functions to use the generic `T` and
also handle the different kinds of `Comment`s -- `Infallible` and
`CodeLocation`.

X-Co-Authored-By: Fintan Halpenny <fintan.halpenny@gmail.com>

radicle-cli/src/terminal/comment.rs

@@ -5,9 +5,9 @@ use crate::terminal as term;
 use crate::terminal::format::Author;
 
 /// Return a comment header as a [`term::Element`].
-pub fn header(
+pub fn header<T>(
     id: &CommentId,
-    comment: &Comment,
+    comment: &Comment<T>,
     profile: &Profile,
 ) -> term::hstack::HStack<'static> {
     let author = comment.author();
@@ -27,7 +27,7 @@ pub fn header(
 }
 
 /// Return a full comment widget as a [`term::Element`].
-pub fn widget<'a>(id: &CommentId, comment: &Comment, profile: &Profile) -> term::VStack<'a> {
+pub fn widget<'a, T>(id: &CommentId, comment: &Comment<T>, profile: &Profile) -> term::VStack<'a> {
     term::vstack::bordered(header(id, comment, profile))
         .child(term::textarea(comment.body()).wrap(60))
 }

radicle-httpd/src/api/json.rs

@@ -103,7 +103,7 @@ pub(crate) fn issue(id: IssueId, issue: Issue, aliases: &impl AliasStore) -> Val
         "title": issue.title(),
         "state": issue.state(),
         "assignees": issue.assignees().collect::<Vec<_>>(),
-        "discussion": issue.comments().map(|(id, c)| comment(id, c, aliases)).collect::<Vec<_>>(),
+        "discussion": issue.comments().map(|(id, c)| issue_comment(id, c, aliases)).collect::<Vec<_>>(),
         "labels": issue.labels().collect::<Vec<_>>(),
     })
 }
@@ -132,7 +132,7 @@ pub(crate) fn patch(
                 "base": rev.base(),
                 "oid": rev.head(),
                 "refs": get_refs(repo, patch.author().id(), &rev.head()).unwrap_or_default(),
-                "discussions": rev.discussion().comments().map(|(id, c)| comment(id, c,  aliases)).collect::<Vec<_>>(),
+                "discussions": rev.discussion().comments().map(|(id, c)| patch_comment(id, c,  aliases)).collect::<Vec<_>>(),
                 "timestamp": rev.timestamp().as_secs(),
                 "reviews": rev.reviews().map(|(nid, r)| review(nid, r, aliases)).collect::<Vec<_>>(),
             })
@@ -172,8 +172,8 @@ fn review(nid: &NodeId, review: &Review, aliases: &impl AliasStore) -> Value {
     })
 }
 
-/// Returns JSON for a `Comment`.
+/// Returns JSON for a Issue `Comment`.
-fn comment(id: &CommentId, comment: &Comment, aliases: &impl AliasStore) -> Value {
+fn issue_comment(id: &CommentId, comment: &Comment, aliases: &impl AliasStore) -> Value {
     json!({
         "id": *id,
         "author": author(&Author::from(comment.author()), aliases.alias(&comment.author())),
@@ -194,6 +194,33 @@ fn comment(id: &CommentId, comment: &Comment, aliases: &impl AliasStore) -> Valu
     })
 }
 
+/// Returns JSON for a Patch `Comment`.
+fn patch_comment(
+    id: &CommentId,
+    comment: &Comment<CodeLocation>,
+    aliases: &impl AliasStore,
+) -> Value {
+    json!({
+        "id": *id,
+        "author": author(&Author::from(comment.author()), aliases.alias(&comment.author())),
+        "body": comment.body(),
+        "edits": comment.edits().map(|edit| {
+          json!({
+            "author": author(&Author::from(edit.author), aliases.alias(&edit.author)),
+            "body": edit.body,
+            "timestamp": edit.timestamp.as_secs(),
+            "embeds": edit.embeds,
+          })
+        }).collect::<Vec<_>>(),
+        "embeds": comment.embeds().to_vec(),
+        "reactions": comment.reactions().collect::<Vec<_>>(),
+        "timestamp": comment.timestamp().as_secs(),
+        "replyTo": comment.reply_to(),
+        "location": comment.location(),
+        "resolved": comment.resolved(),
+    })
+}
+
 /// Returns JSON for a `Review`.
 fn review_comment(
     id: &CommentId,

radicle-httpd/src/api/v1/projects.rs

@@ -3041,6 +3041,7 @@ mod routes {
                       "reactions": [["z6Mkk7oqY4pPxhMmGEotDYsFo97vhCj85BLY1H256HrJmjN8","🚀"]],
                       "timestamp": TIMESTAMP,
                       "replyTo": null,
+                      "location": null,
                       "resolved": false,
                     },
                     {
@@ -3063,6 +3064,7 @@ mod routes {
                       "reactions": [],
                       "timestamp": TIMESTAMP,
                       "replyTo": comment_id,
+                      "location": null,
                       "resolved": false,
                     },
                   ],

radicle/src/cob/patch.rs

@@ -1012,7 +1012,7 @@ impl Patch {
                 body,
                 reply_to,
                 embeds,
-                ..
+                location,
             } => {
                 if let Some(revision) = lookup::revision_mut(self, &revision)? {
                     thread::comment(
@@ -1022,7 +1022,7 @@ impl Patch {
                         timestamp,
                         body,
                         reply_to,
-                        None,
+                        location,
                         embeds,
                     )?;
                 }
@@ -1255,7 +1255,7 @@ pub struct Revision {
     /// Reference to the Git object containing the code (revision head).
     pub(super) oid: git::Oid,
     /// Discussion around this revision.
-    pub(super) discussion: Thread<Comment>,
+    pub(super) discussion: Thread<Comment<CodeLocation>>,
     /// Reviews of this revision's changes (one per actor).
     pub(super) reviews: BTreeMap<ActorId, Option<Review>>,
     /// When this revision was created.
@@ -1313,7 +1313,7 @@ impl Revision {
     }
 
     /// Discussion around this revision.
-    pub fn discussion(&self) -> &Thread<Comment> {
+    pub fn discussion(&self) -> &Thread<Comment<CodeLocation>> {
         &self.discussion
     }
 

radicle/src/cob/thread.rs

@@ -1,5 +1,6 @@
 use std::cmp::Ordering;
 use std::collections::{BTreeMap, BTreeSet};
+use std::convert::Infallible;
 use std::str::FromStr;
 
 use once_cell::sync::Lazy;
@@ -67,7 +68,7 @@ pub struct Edit {
 
 /// A comment on a discussion thread.
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Comment<T = ()> {
+pub struct Comment<T = Infallible> {
     /// Comment author.
     author: ActorId,
     /// The comment body.
@@ -265,7 +266,7 @@ impl From<Action> for nonempty::NonEmpty<Action> {
 
 /// A discussion thread.
 #[derive(Debug, Clone, PartialEq, Eq)]
-pub struct Thread<T = Comment<()>> {
+pub struct Thread<T = Comment> {
     /// The comments under the thread.
     pub(crate) comments: BTreeMap<CommentId, Option<T>>,
     /// Comment timeline.