revset: add change_id/commit_id(prefix) predicates

Basically, these functions work in the same way as bookmarks()/tags(). They
restrict the namespace to search the specified symbol, and unmatched symbol
isn't an error. One major difference is that ambiguous prefix triggers an error.
That's because ambiguous prefix should logically select all matching entries,
whereas the underlying functions don't provide this behavior. It's also unclear
whether we would want to get all matching commits by commit_id(prefix:'').

#5632

Author: yuja

CHANGELOG.md

@@ -40,6 +40,9 @@ to [Semantic Versioning](https://semver.org/spec/v2.0.0.html).
   `depth` argument. For instance, `parents(x, 3)` is equivalent to `x---`, and
   `children(x, 3)` is equivalent to `x+++`.
 
+* New `change_id(prefix)`/`commit_id(prefix)` revset functions to explicitly
+  query commits by change/commit ID prefix.
+
 ### Fixed bugs
 
 * `jj file annotate` can now process files at a hidden revision.

cli/tests/test_revset_output.rs

@@ -172,6 +172,34 @@ fn test_bad_function_call() {
     [exit status: 1]
     ");
 
+    let output = work_dir.run_jj(["log", "-r", "change_id(glob:a)"]);
+    insta::assert_snapshot!(output, @r"
+    ------- stderr -------
+    Error: Failed to parse revset: Expected change ID prefix
+    Caused by:  --> 1:11
+      |
+    1 | change_id(glob:a)
+      |           ^----^
+      |
+      = Expected change ID prefix
+    [EOF]
+    [exit status: 1]
+    ");
+
+    let output = work_dir.run_jj(["log", "-r", "commit_id(xyzzy)"]);
+    insta::assert_snapshot!(output, @r"
+    ------- stderr -------
+    Error: Failed to parse revset: Invalid commit ID prefix
+    Caused by:  --> 1:11
+      |
+    1 | commit_id(xyzzy)
+      |           ^---^
+      |
+      = Invalid commit ID prefix
+    [EOF]
+    [exit status: 1]
+    ");
+
     let output = work_dir.run_jj(["log", "-r", "files(not::a-fileset)"]);
     insta::assert_snapshot!(output, @r"
     ------- stderr -------

docs/revsets.md

@@ -211,6 +211,12 @@ revsets (expressions) as arguments.
 * `none()`: No commits. This function is rarely useful; it is provided for
   completeness.
 
+* `change_id(prefix)`: Commits with the given change ID prefix. It is an error
+  to use a non-unique prefix. Unmatched prefix isn't an error.
+
+* `commit_id(prefix)`: Commits with the given commit ID prefix. It is an error
+  to use a non-unique prefix. Unmatched prefix isn't an error.
+
 * `bookmarks([pattern])`: All local bookmark targets. If `pattern` is specified,
   this selects the bookmarks whose name match the given [string
   pattern](#string-patterns). For example, `bookmarks(push)` would match the

lib/src/revset.rs

@@ -134,6 +134,8 @@ pub enum RevsetCommitRef {
     WorkingCopies,
     Symbol(String),
     RemoteSymbol(RemoteRefSymbolBuf),
+    ChangeId(HexPrefix),
+    CommitId(HexPrefix),
     Bookmarks(StringPattern),
     RemoteBookmarks {
         bookmark_pattern: StringPattern,
@@ -366,6 +368,16 @@ impl<St: ExpressionState<CommitRef = RevsetCommitRef>> RevsetExpression<St> {
         Rc::new(Self::CommitRef(commit_ref))
     }
 
+    pub fn change_id_prefix(prefix: HexPrefix) -> Rc<Self> {
+        let commit_ref = RevsetCommitRef::ChangeId(prefix);
+        Rc::new(Self::CommitRef(commit_ref))
+    }
+
+    pub fn commit_id_prefix(prefix: HexPrefix) -> Rc<Self> {
+        let commit_ref = RevsetCommitRef::CommitId(prefix);
+        Rc::new(Self::CommitRef(commit_ref))
+    }
+
     pub fn bookmarks(pattern: StringPattern) -> Rc<Self> {
         Rc::new(Self::CommitRef(RevsetCommitRef::Bookmarks(pattern)))
     }
@@ -764,6 +776,24 @@ static BUILTIN_FUNCTION_MAP: Lazy<HashMap<&'static str, RevsetFunction>> = Lazy:
         function.expect_no_arguments()?;
         Ok(RevsetExpression::root())
     });
+    map.insert("change_id", |diagnostics, function, _context| {
+        let [arg] = function.expect_exact_arguments()?;
+        let prefix = revset_parser::catch_aliases(diagnostics, arg, |_diagnostics, arg| {
+            let value = revset_parser::expect_string_literal("change ID prefix", arg)?;
+            HexPrefix::try_from_reverse_hex(value)
+                .ok_or_else(|| RevsetParseError::expression("Invalid change ID prefix", arg.span))
+        })?;
+        Ok(RevsetExpression::change_id_prefix(prefix))
+    });
+    map.insert("commit_id", |diagnostics, function, _context| {
+        let [arg] = function.expect_exact_arguments()?;
+        let prefix = revset_parser::catch_aliases(diagnostics, arg, |_diagnostics, arg| {
+            let value = revset_parser::expect_string_literal("commit ID prefix", arg)?;
+            HexPrefix::new(value)
+                .ok_or_else(|| RevsetParseError::expression("Invalid commit ID prefix", arg.span))
+        })?;
+        Ok(RevsetExpression::commit_id_prefix(prefix))
+    });
     map.insert("bookmarks", |diagnostics, function, _context| {
         let ([], [opt_arg]) = function.expect_arguments()?;
         let pattern = if let Some(arg) = opt_arg {
@@ -2533,6 +2563,14 @@ fn resolve_commit_ref(
             let wc_commits = repo.view().wc_commit_ids().values().cloned().collect_vec();
             Ok(wc_commits)
         }
+        RevsetCommitRef::ChangeId(prefix) => {
+            let resolver = &symbol_resolver.change_id_resolver;
+            Ok(resolver.try_resolve(repo, prefix)?.unwrap_or_else(Vec::new))
+        }
+        RevsetCommitRef::CommitId(prefix) => {
+            let resolver = &symbol_resolver.commit_id_resolver;
+            Ok(resolver.try_resolve(repo, prefix)?.into_iter().collect())
+        }
         RevsetCommitRef::Bookmarks(pattern) => {
             let commit_ids = repo
                 .view()
@@ -3720,6 +3758,32 @@ mod tests {
         insta::assert_debug_snapshot!(parse("signed()").unwrap(), @"Filter(Signed)");
     }
 
+    #[test]
+    fn test_parse_revset_change_commit_id_functions() {
+        let settings = insta_settings();
+        let _guard = settings.bind_to_scope();
+
+        insta::assert_debug_snapshot!(
+            parse("change_id(z)").unwrap(),
+            @r#"CommitRef(ChangeId(HexPrefix("0")))"#);
+        insta::assert_debug_snapshot!(
+            parse("change_id('zk')").unwrap(),
+            @r#"CommitRef(ChangeId(HexPrefix("0f")))"#);
+        insta::assert_debug_snapshot!(
+            parse("change_id(01234)").unwrap_err().kind(),
+            @r#"Expression("Invalid change ID prefix")"#);
+
+        insta::assert_debug_snapshot!(
+            parse("commit_id(0)").unwrap(),
+            @r#"CommitRef(CommitId(HexPrefix("0")))"#);
+        insta::assert_debug_snapshot!(
+            parse("commit_id('0f')").unwrap(),
+            @r#"CommitRef(CommitId(HexPrefix("0f")))"#);
+        insta::assert_debug_snapshot!(
+            parse("commit_id(xyzzy)").unwrap_err().kind(),
+            @r#"Expression("Invalid commit ID prefix")"#);
+    }
+
     #[test]
     fn test_parse_revset_author_committer_functions() {
         let settings = insta_settings();

lib/tests/test_revset.rs

@@ -224,6 +224,32 @@ fn test_resolve_symbol_commit_id() {
         resolve_commit_ids(repo.as_ref(), "present(017)"),
         vec![commits[2].id().clone()]
     );
+
+    // Test commit_id() function, which is roughly equivalent to present(id)
+    assert_eq!(
+        resolve_symbol(
+            repo.as_ref(),
+            "commit_id(019f179b4479a4f3d1373b772866037929e4f63c)",
+        )
+        .unwrap(),
+        vec![commits[0].id().clone()]
+    );
+    assert_eq!(
+        resolve_symbol(repo.as_ref(), "commit_id(019f1)").unwrap(),
+        vec![commits[0].id().clone()]
+    );
+    assert_eq!(
+        resolve_symbol(repo.as_ref(), "commit_id(12345)").unwrap(),
+        vec![]
+    );
+    assert_matches!(
+        resolve_symbol(repo.as_ref(), "commit_id('')"),
+        Err(RevsetResolutionError::AmbiguousCommitIdPrefix(s)) if s.is_empty()
+    );
+    assert_matches!(
+        resolve_symbol(repo.as_ref(), "commit_id(0)"),
+        Err(RevsetResolutionError::AmbiguousCommitIdPrefix(s)) if s == "0"
+    );
 }
 
 #[test_case(false ; "mutable")]
@@ -347,6 +373,25 @@ fn test_resolve_symbol_change_id(readonly: bool) {
             candidates
         }) if name == "foo" && candidates.is_empty()
     );
+
+    // Test change_id() function, which is roughly equivalent to present(id)
+    assert_eq!(
+        resolve_symbol(repo, "change_id(zvlyxpuvtsoopsqzlkorrpqrszrqvlnx)").unwrap(),
+        vec![commits[0].id().clone()]
+    );
+    assert_eq!(
+        resolve_symbol(repo, "change_id(zvlyx)").unwrap(),
+        vec![commits[0].id().clone()]
+    );
+    assert_eq!(resolve_symbol(repo, "change_id(xyzzy)").unwrap(), vec![]);
+    assert_matches!(
+        resolve_symbol(repo, "change_id('')"),
+        Err(RevsetResolutionError::AmbiguousChangeIdPrefix(s)) if s.is_empty()
+    );
+    assert_matches!(
+        resolve_symbol(repo, "change_id(z)"),
+        Err(RevsetResolutionError::AmbiguousChangeIdPrefix(s)) if s == "z"
+    );
 }
 
 #[test]