pre-commit · Freed-Wu · Sep 20, 2026
diff --git a/pre_commit_mirror_maker/languages.py b/pre_commit_mirror_maker/languages.py
@@ -36,6 +36,16 @@ def rust_get_package_versions(package_name: str) -> list[str]:
     return list(reversed([version['num'] for version in resp['versions']]))
 
 
+def haskell_get_package_versions(package_name: str) -> list[str]:
+    url = f'https://hackage.haskell.org/package/{package_name}/preferred.json'
+    resp = json.load(urllib.request.urlopen(url))
+    versions = {
+        *resp.get('normal-version', ()),
+        *resp.get('deprecated-version', ()),
+    }
+    return sorted(versions, key=version.parse)
+
+
 def golang_get_package_versions(package_name: str) -> list[str]:
     # https://pkg.go.dev/golang.org/x/mod/module#EscapePath
     # https://github.com/golang/mod/blob/d271cf332fd221d661d13b186b51a11d7e66ff74/module/module.go#L707
@@ -78,6 +88,12 @@ def rust_get_additional_dependencies(
     return [f'cli:{package_name}:{package_version}']
 
 
+def haskell_get_additional_dependencies(
+        package_name: str, package_version: str,
+) -> list[str]:
+    return [f'{package_name}-{package_version}']
+
+
 def golang_get_additional_dependencies(
         package_name: str, package_version: str,
 ) -> list[str]:
@@ -86,6 +102,7 @@ def golang_get_additional_dependencies(
 
 LIST_VERSIONS = {
     'golang': golang_get_package_versions,
+    'haskell': haskell_get_package_versions,
     'node': node_get_package_versions,
     'python': python_get_package_versions,
     'ruby': ruby_get_package_versions,
@@ -94,6 +111,7 @@ def golang_get_additional_dependencies(
 
 ADDITIONAL_DEPENDENCIES = {
     'golang': golang_get_additional_dependencies,
+    'haskell': haskell_get_additional_dependencies,
     'node': node_get_additional_dependencies,
     'rust': rust_get_additional_dependencies,
 }
diff --git a/pre_commit_mirror_maker/make_repo.py b/pre_commit_mirror_maker/make_repo.py
@@ -50,6 +50,8 @@ def _commit_version(
     with importlib.resources.as_file(files) as files_p:
         for lang in ('all', language):
             src = files_p.joinpath(lang)
+            if not os.path.exists(src):
+                continue
             format_files(
                 src,
                 repo,

diff --git a/tests/languages_test.py b/tests/languages_test.py
@@ -3,6 +3,7 @@
 import pytest
 
 from pre_commit_mirror_maker.languages import golang_get_package_versions
+from pre_commit_mirror_maker.languages import haskell_get_package_versions
 from pre_commit_mirror_maker.languages import node_get_package_versions
 from pre_commit_mirror_maker.languages import python_get_package_versions
 from pre_commit_mirror_maker.languages import ruby_get_package_versions
@@ -44,6 +45,12 @@ def test_rust_get_package_version_output():
     assert_all_text(ret)
 
 
+def test_haskell_get_package_version_output():
+    ret = haskell_get_package_versions('hlint')
+    assert ret
+    assert_all_text(ret)
+
+
 @pytest.mark.parametrize(
     'package_name',
     (

diff --git a/tests/main_test.py b/tests/main_test.py
@@ -47,6 +47,22 @@ def test_main_passes_args(mock_make_repo):
     )
 
 
+def test_main_passes_haskell_args(mock_make_repo):
+    assert not main.main((
+        '.',
+        '--language', 'haskell',
+        '--package-name', 'hlint',
+        '--types', 'haskell',
+    ))
+    mock_make_repo.assert_called_once_with(
+        '.',
+        language='haskell', name='hlint', description='',
+        entry='hlint',
+        id='hlint', match_key='types', match_val='[haskell]', args='[]',
+        require_serial='false', minimum_pre_commit_version='0',
+    )
+
+
 def test_main_defaults_entry_to_package_name(mock_make_repo):
     assert not main.main((
         '.',

diff --git a/tests/make_repo_test.py b/tests/make_repo_test.py
@@ -284,3 +284,22 @@ def test_golang_integration(in_git_dir):
     assert _cmd('git', 'log', '--oneline')
 
     # TODO: test that the package is installable
+
+
+def test_haskell_integration(in_git_dir):
+    make_repo(
+        '.',
+        language='haskell', name='hlint', description='',
+        entry='hlint', id='hlint', match_key='types', match_val='haskell',
+        args='[]', require_serial='false', minimum_pre_commit_version='0',
+    )
+    assert in_git_dir.join('.version').exists()
+    assert in_git_dir.join('.pre-commit-hooks.yaml').exists()
+
+    contents = in_git_dir.join('.pre-commit-hooks.yaml').read()
+    assert yaml.safe_load(contents)[0]['additional_dependencies'] == [
+        f"hlint-{in_git_dir.join('.version').read().strip()}",
+    ]
+
+    assert _cmd('git', 'tag', '-l')
+    assert _cmd('git', 'log', '--oneline')