1 files changed, 111 insertions, 0 deletions
diff --git a/pre_commit/languages/dotnet.py b/pre_commit/languages/dotnet.py
new file mode 100644
index 0000000..e1202c4
--- /dev/null
+++ b/pre_commit/languages/dotnet.py
@@ -0,0 +1,111 @@
+from __future__ import annotations
+
+import contextlib
+import os.path
+import re
+import tempfile
+import xml.etree.ElementTree
+import zipfile
+from collections.abc import Generator
+from collections.abc import Sequence
+
+from pre_commit import lang_base
+from pre_commit.envcontext import envcontext
+from pre_commit.envcontext import PatchesT
+from pre_commit.envcontext import Var
+from pre_commit.prefix import Prefix
+
+ENVIRONMENT_DIR = 'dotnetenv'
+BIN_DIR = 'bin'
+
+get_default_version = lang_base.basic_get_default_version
+health_check = lang_base.basic_health_check
+run_hook = lang_base.basic_run_hook
+
+
+def get_env_patch(venv: str) -> PatchesT:
+    return (
+        ('PATH', (os.path.join(venv, BIN_DIR), os.pathsep, Var('PATH'))),
+    )
+
+
+@contextlib.contextmanager
+def in_env(prefix: Prefix, version: str) -> Generator[None, None, None]:
+    envdir = lang_base.environment_dir(prefix, ENVIRONMENT_DIR, version)
+    with envcontext(get_env_patch(envdir)):
+        yield
+
+
+@contextlib.contextmanager
+def _nuget_config_no_sources() -> Generator[str, None, None]:
+    with tempfile.TemporaryDirectory() as tmpdir:
+        nuget_config = os.path.join(tmpdir, 'nuget.config')
+        with open(nuget_config, 'w') as f:
+            f.write(
+                '<?xml version="1.0" encoding="utf-8"?>'
+                '<configuration>'
+                '  <packageSources>'
+                '    <clear />'
+                '  </packageSources>'
+                '</configuration>',
+            )
+        yield nuget_config
+
+
+def install_environment(
+        prefix: Prefix,
+        version: str,
+        additional_dependencies: Sequence[str],
+) -> None:
+    lang_base.assert_version_default('dotnet', version)
+    lang_base.assert_no_additional_deps('dotnet', additional_dependencies)
+
+    envdir = lang_base.environment_dir(prefix, ENVIRONMENT_DIR, version)
+    build_dir = prefix.path('pre-commit-build')
+
+    # Build & pack nupkg file
+    lang_base.setup_cmd(
+        prefix,
+        (
+            'dotnet', 'pack',
+            '--configuration', 'Release',
+            '--property', f'PackageOutputPath={build_dir}',
+        ),
+    )
+
+    nupkg_dir = prefix.path(build_dir)
+    nupkgs = [x for x in os.listdir(nupkg_dir) if x.endswith('.nupkg')]
+
+    if not nupkgs:
+        raise AssertionError('could not find any build outputs to install')
+
+    for nupkg in nupkgs:
+        with zipfile.ZipFile(os.path.join(nupkg_dir, nupkg)) as f:
+            nuspec, = (x for x in f.namelist() if x.endswith('.nuspec'))
+            with f.open(nuspec) as spec:
+                tree = xml.etree.ElementTree.parse(spec)
+
+        namespace = re.match(r'{.*}', tree.getroot().tag)
+        if not namespace:
+            raise AssertionError('could not parse namespace from nuspec')
+
+        tool_id_element = tree.find(f'.//{namespace[0]}id')
+        if tool_id_element is None:
+            raise AssertionError('expected to find an "id" element')
+
+        tool_id = tool_id_element.text
+        if not tool_id:
+            raise AssertionError('"id" element missing tool name')
+
+        # Install to bin dir
+        with _nuget_config_no_sources() as nuget_config:
+            lang_base.setup_cmd(
+                prefix,
+                (
+                    'dotnet', 'tool', 'install',
+                    '--configfile', nuget_config,
+                    '--tool-path', os.path.join(envdir, BIN_DIR),
+                    '--add-source', build_dir,
+                    tool_id,
+                ),
+            )