log: encode elided commit as None (PoC)

Note that "if(self && root, ..)" doesn't work because the templater doesn't
support short-circuiting as of now. "if(self, if(root, ..))" works.

cli/src/commands/log.rs

@@ -110,7 +110,10 @@ pub(crate) fn cmd_log(
         .settings()
         .config()
         .get_bool("ui.log-synthetic-elided-nodes")?;
-    let template = workspace_command.parse_commit_template(&template_string)?;
+    let template = {
+        let language = workspace_command.commit_template_language()?;
+        workspace_command.parse_template(&language, &template_string)?
+    };
     let with_content_format = LogContentFormat::new(ui, command.settings())?;
 
     {
@@ -159,7 +162,7 @@ pub(crate) fn cmd_log(
                 }
                 let mut buffer = vec![];
                 let key = (commit_id, false);
-                let commit = store.get_commit(&key.0)?;
+                let commit = Some(store.get_commit(&key.0)?);
                 with_content_format.write_graph_text(
                     ui.new_formatter(&mut buffer).as_mut(),
                     |formatter| template.format(&commit, formatter),
@@ -174,7 +177,7 @@ pub(crate) fn cmd_log(
                         ui,
                         formatter.as_mut(),
                         &workspace_command,
-                        &commit,
+                        commit.as_ref().unwrap(),
                         matcher.as_ref(),
                         &diff_formats,
                     )?;
@@ -198,7 +201,7 @@ pub(crate) fn cmd_log(
                     let mut buffer = vec![];
                     with_content_format.write_graph_text(
                         ui.new_formatter(&mut buffer).as_mut(),
-                        |formatter| writeln!(formatter.labeled("elided"), "(elided revisions)"),
+                        |formatter| template.format(&None, formatter),
                         || graph.width(&elided_key, &edges),
                     )?;
                     graph.add_node(
@@ -216,15 +219,15 @@ pub(crate) fn cmd_log(
                 Box::new(revset.iter())
             };
             for commit_or_error in iter.commits(store).take(args.limit.unwrap_or(usize::MAX)) {
-                let commit = commit_or_error?;
+                let commit = Some(commit_or_error?);
                 with_content_format
                     .write(formatter, |formatter| template.format(&commit, formatter))?;
                 if !diff_formats.is_empty() {
                     diff_util::show_patch(
                         ui,
                         formatter,
                         &workspace_command,
-                        &commit,
+                        commit.as_ref().unwrap(),
                         matcher.as_ref(),
                         &diff_formats,
                     )?;

cli/src/config/templates.toml

@@ -41,52 +41,59 @@ show = 'builtin_log_detailed'
 
 [template-aliases]
 builtin_log_oneline = '''
-if(root,
-  builtin_log_root(change_id, commit_id),
-  label(if(current_working_copy, "working_copy"),
-    concat(
-      separate(" ",
-        builtin_change_id_with_hidden_and_divergent_info,
-        if(author.email(), author.username(), email_placeholder),
-        format_timestamp(committer.timestamp()),
-        branches,
-        tags,
-        working_copies,
-        git_head,
-        format_short_commit_id(commit_id),
-        if(conflict, label("conflict", "conflict")),
-        if(empty, label("empty", "(empty)")),
-        if(description, description.first_line(), description_placeholder),
-      ) ++ "\n",
+if(self,
+  if(root,
+    builtin_log_root(change_id, commit_id),
+    label(if(current_working_copy, "working_copy"),
+      concat(
+        separate(" ",
+          builtin_change_id_with_hidden_and_divergent_info,
+          if(author.email(), author.username(), email_placeholder),
+          format_timestamp(committer.timestamp()),
+          branches,
+          tags,
+          working_copies,
+          git_head,
+          format_short_commit_id(commit_id),
+          if(conflict, label("conflict", "conflict")),
+          if(empty, label("empty", "(empty)")),
+          if(description, description.first_line(), description_placeholder),
+        ) ++ "\n",
+      ),
     ),
-  )
+  ),
+  elided_revisions_placeholder ++ "\n",
 )
 '''
 builtin_log_compact = '''
-if(root,
-  builtin_log_root(change_id, commit_id),
-  label(if(current_working_copy, "working_copy"),
-    concat(
-      separate(" ",
-        builtin_change_id_with_hidden_and_divergent_info,
-        format_short_signature(author),
-        format_timestamp(committer.timestamp()),
-        branches,
-        tags,
-        working_copies,
-        git_head,
-        format_short_commit_id(commit_id),
-        if(conflict, label("conflict", "conflict")),
-      ) ++ "\n",
-      separate(" ",
-        if(empty, label("empty", "(empty)")),
-        if(description, description.first_line(), description_placeholder),
-      ) ++ "\n",
+if(self,
+  if(root,
+    builtin_log_root(change_id, commit_id),
+    label(if(current_working_copy, "working_copy"),
+      concat(
+        separate(" ",
+          builtin_change_id_with_hidden_and_divergent_info,
+          format_short_signature(author),
+          format_timestamp(committer.timestamp()),
+          branches,
+          tags,
+          working_copies,
+          git_head,
+          format_short_commit_id(commit_id),
+          if(conflict, label("conflict", "conflict")),
+        ) ++ "\n",
+        separate(" ",
+          if(empty, label("empty", "(empty)")),
+          if(description, description.first_line(), description_placeholder),
+        ) ++ "\n",
+      ),
     ),
-  )
+  ),
+  elided_revisions_placeholder ++ "\n",
 )
 '''
 builtin_log_comfortable = 'builtin_log_compact ++ "\n"'
+# TODO: should the detailed (or show) template support elided nodes?
 'builtin_log_detailed' = '''
 concat(
   "Commit ID: " ++ commit_id ++ "\n",
@@ -138,6 +145,7 @@ separate(" ",
 
 description_placeholder = '''
   label(if(empty, "empty ") ++ "description placeholder", "(no description set)")'''
+elided_revisions_placeholder = 'label("elided", "(elided revisions)")'
 email_placeholder = 'label("email placeholder", "(no email set)")'
 name_placeholder = 'label("name placeholder", "(no name set)")'
 commit_summary_separator = 'label("separator", " | ")'

cli/tests/test_log_command.rs

@@ -49,6 +49,7 @@ fn test_log_with_no_template() {
     - builtin_op_log_compact
     - commit_summary_separator
     - description_placeholder
+    - elided_revisions_placeholder
     - email_placeholder
     - name_placeholder
     "###);
@@ -1388,10 +1389,10 @@ fn test_elided() {
     ├─╮
     │ ◉  side branch 2
     │ │
-    │ ◌  (elided revisions)
+    │ ◌  <Error: No commit available>
     ◉ │  main branch 2
     │ │
-    ◌ │  (elided revisions)
+    ◌ │  <Error: No commit available>
     ├─╯
     ◉  initial
     │
@@ -1403,10 +1404,10 @@ fn test_elided() {
     insta::assert_snapshot!(get_log("@-- | root()"), @r###"
     ◉  side branch 1
     │
-    ◌  (elided revisions)
+    ◌  <Error: No commit available>
     │ ◉  main branch 1
     │ │
-    │ ◌  (elided revisions)
+    │ ◌  <Error: No commit available>
     ├─╯
     ◉
     "###);
@@ -1447,10 +1448,10 @@ fn test_custom_symbols() {
     ├─╮
     │ ┝  side branch 2
     │ │
-    │ 🮀  (elided revisions)
+    │ 🮀  <Error: No commit available>
     ┝ │  main branch 2
     │ │
-    🮀 │  (elided revisions)
+    🮀 │  <Error: No commit available>
     ├─╯
     ┝  initial
     │
@@ -1469,10 +1470,10 @@ fn test_custom_symbols() {
     |\
     | *  side branch 2
     | |
-    | :  (elided revisions)
+    | :  <Error: No commit available>
     * |  main branch 2
     | |
-    : |  (elided revisions)
+    : |  <Error: No commit available>
     |/
     *  initial
     |

cli/tests/test_obslog_command.rs

@@ -257,6 +257,7 @@ fn test_obslog_with_no_template() {
     - builtin_op_log_compact
     - commit_summary_separator
     - description_placeholder
+    - elided_revisions_placeholder
     - email_placeholder
     - name_placeholder
     "###);

cli/tests/test_operations.rs

@@ -114,6 +114,7 @@ fn test_op_log_with_no_template() {
     - builtin_op_log_compact
     - commit_summary_separator
     - description_placeholder
+    - elided_revisions_placeholder
     - email_placeholder
     - name_placeholder
     "###);

cli/tests/test_show_command.rs

@@ -69,6 +69,7 @@ fn test_show_with_no_template() {
     - builtin_op_log_compact
     - commit_summary_separator
     - description_placeholder
+    - elided_revisions_placeholder
     - email_placeholder
     - name_placeholder
     "###);