feat(gitcommit): use tree-sitter for gitcommit

The previous gitcommit parser naively took the contents until the
first comment. If there are inline comments, such as when squashing two
commits in an interactive rebase, the text after those comments would
not be checked.

Instead, we use tree-sitter-gitcommit parsing and mask the nodes that
are subject, message lines or breaking change descriptions. As before,
we re-parse these parts with the existing markdown parser.

A new crate `harper-git-commit` is added.

Author: Tijs-B

Cargo.lock

@@ -1,5 +1,5 @@
 [workspace]
-members = ["harper-cli", "harper-core", "harper-ls", "harper-comments", "harper-wasm", "harper-tree-sitter", "harper-html", "harper-literate-haskell", "harper-typst", "harper-stats", "harper-pos-utils", "harper-brill", "harper-ink", "harper-python"]
+members = ["harper-cli", "harper-core", "harper-ls", "harper-comments", "harper-wasm", "harper-tree-sitter", "harper-html", "harper-literate-haskell", "harper-typst", "harper-stats", "harper-pos-utils", "harper-brill", "harper-ink", "harper-python", "harper-git-commit"]
 resolver = "2"
 
 # Comment out the below lines if you plan to use a debugger.

Cargo.toml

@@ -0,0 +1,16 @@
+[package]
+name = "harper-git-commit"
+version = "0.67.0"
+edition = "2024"
+description = "The language checker for developers."
+license = "Apache-2.0"
+repository = "https://github.com/automattic/harper"
+
+[dependencies]
+harper-core = { path = "../harper-core", version = "0.67.0" }
+harper-tree-sitter = { path = "../harper-tree-sitter", version = "0.67.0" }
+tree-sitter-gitcommit = { git = "https://github.com/gbprod/tree-sitter-gitcommit", rev = "a716678c0f00645fed1e6f1d0eb221481dbd6f6d" }
+tree-sitter = "0.25.10"
+
+[dev-dependencies]
+paste = "1.0.15"

harper-git-commit/Cargo.toml

@@ -0,0 +1,30 @@
+use harper_core::Token;
+use harper_core::parsers::{self, Markdown, MarkdownOptions, Parser};
+use harper_tree_sitter::TreeSitterMasker;
+use tree_sitter::Node;
+
+pub struct GitCommitParser {
+    /// Used to grab the text nodes, and parse them as markdown.
+    inner: parsers::Mask<TreeSitterMasker, Markdown>,
+}
+
+impl GitCommitParser {
+    fn node_condition(n: &Node) -> bool {
+        matches!(n.kind(), "subject" | "message_line" | "breaking_change")
+    }
+
+    pub fn new(markdown_options: MarkdownOptions) -> Self {
+        Self {
+            inner: parsers::Mask::new(
+                TreeSitterMasker::new(tree_sitter_gitcommit::language(), Self::node_condition),
+                Markdown::new(markdown_options),
+            ),
+        }
+    }
+}
+
+impl Parser for GitCommitParser {
+    fn parse(&self, source: &[char]) -> Vec<Token> {
+        self.inner.parse(source)
+    }
+}

harper-git-commit/src/lib.rs

@@ -0,0 +1,41 @@
+use harper_core::linting::{LintGroup, Linter};
+use harper_core::parsers::MarkdownOptions;
+use harper_core::spell::FstDictionary;
+use harper_core::{Dialect, Document};
+use harper_git_commit::GitCommitParser;
+
+/// Creates a unit test checking that the linting of a git commit document (in
+/// `tests_sources`) produces the expected number of lints.
+macro_rules! create_test {
+    ($filename:ident.txt, $correct_expected:expr) => {
+        paste::paste! {
+            #[test]
+            fn [<lints_ $filename _correctly>](){
+                 let source = include_str!(
+                    concat!(
+                        "./test_sources/",
+                        concat!(stringify!($filename), ".txt")
+                    )
+                 );
+
+                 let dict = FstDictionary::curated();
+                 let document = Document::new(source, &GitCommitParser::new(MarkdownOptions::default()), &dict);
+
+                 let mut linter = LintGroup::new_curated(dict, Dialect::American);
+                 let lints = linter.lint(&document);
+
+                 dbg!(&lints);
+                 assert_eq!(lints.len(), $correct_expected);
+
+                 // Make sure that all generated tokens span real characters
+                 for token in document.tokens(){
+                     assert!(token.span.try_get_content(document.get_source()).is_some());
+                 }
+            }
+        }
+    };
+}
+
+create_test!(simple_commit.txt, 1);
+create_test!(complex_verbose_commit.txt, 2);
+create_test!(conventional_commit.txt, 2);

harper-git-commit/tests/run_tests.rs

@@ -0,0 +1,26 @@
+This is the the subject
+
+This is a first line without typos
+# This is a comment
+This is a line below the comment with typooos
+
+# Please enter the commit message for your changes. Lines starting
+# with '#' will be ignored, and an empty message aborts the commit.
+#
+# On branch main
+#
+# Initial commit
+#
+# Changes to be committed:
+#new file:   myfile.txt
+#
+# ------------------------ >8 ------------------------
+# Do not modify or remove the line above.
+# Everything below it will be ignored.
+diff --git a/myfile.txt b/myfile.txt
+new file mode 100644
+index 0000000..485c415
+--- /dev/null
++++ b/myfile.txt
+@@ -0,0 +1 @@
++some textt in the file that was added (the typo should be ignored)

harper-git-commit/tests/test_sources/complex_verbose_commit.txt

@@ -0,0 +1,17 @@
+feat(stuff): use session-based authentiation
+
+BREAKING CHANGE: JWT authentication removed. API clients mustt now use
+session cookies instead of Authorization headers with bearer tokens.
+
+Sessions expire after 24 hours of inactvity.
+
+Closes: #247
+Reviewed-by: John Doe <john@example.com>
+
+# Please enter the commit message for your changes. Lines starting
+# with '#' will be ignored, and an empty message aborts the commit.
+#
+# On branch main
+# Changes to be committed:
+#	modified:   myfile.txt
+#

harper-git-commit/tests/test_sources/conventional_commit.txt

@@ -0,0 +1 @@
+A simple commit with a typo: comit

harper-git-commit/tests/test_sources/simple_commit.txt

@@ -12,6 +12,7 @@ harper-stats = { path = "../harper-stats", version = "0.67.0" }
 harper-literate-haskell = { path = "../harper-literate-haskell", version = "0.67.0" }
 harper-core = { path = "../harper-core", version = "0.67.0", features = ["concurrent"] }
 harper-comments = { path = "../harper-comments", version = "0.67.0" }
+harper-git-commit = { path = "../harper-git-commit", version = "0.67.0" }
 harper-typst = { path = "../harper-typst", version = "0.67.0" }
 harper-html = { path = "../harper-html", version = "0.67.0" }
 harper-python = { path = "../harper-python", version = "0.67.0" }

harper-ls/Cargo.toml

@@ -7,7 +7,6 @@ use std::sync::Arc;
 use crate::config::Config;
 use crate::dictionary_io::{load_dict, save_dict};
 use crate::document_state::DocumentState;
-use crate::git_commit_parser::GitCommitParser;
 use crate::ignored_lints_io::{load_ignored_lints, save_ignored_lints};
 use crate::io_utils::fileify_path;
 use anyhow::{Context, Result, anyhow};
@@ -19,6 +18,7 @@ use harper_core::parsers::{
 };
 use harper_core::spell::{Dictionary, FstDictionary, MergedDictionary, MutableDictionary};
 use harper_core::{Dialect, DictWordMetadata, Document, IgnoredLints};
+use harper_git_commit::GitCommitParser;
 use harper_html::HtmlParser;
 use harper_ink::InkParser;
 use harper_literate_haskell::LiterateHaskellParser;
@@ -382,9 +382,7 @@ impl Backend {
             }
             "ink" => Some(Box::new(InkParser::default())),
             "markdown" => Some(Box::new(Markdown::new(markdown_options))),
-            "git-commit" | "gitcommit" => {
-                Some(Box::new(GitCommitParser::new_markdown(markdown_options)))
-            }
+            "git-commit" | "gitcommit" => Some(Box::new(GitCommitParser::new(markdown_options))),
             "html" => Some(Box::new(HtmlParser::default())),
             "mail" | "plaintext" | "text" => Some(Box::new(PlainEnglish)),
             "typst" => Some(Box::new(Typst)),