1 files changed, 145 insertions, 0 deletions
diff --git a/pre_commit/languages/ruby.py b/pre_commit/languages/ruby.py
new file mode 100644
index 0000000..0438ae0
--- /dev/null
+++ b/pre_commit/languages/ruby.py
@@ -0,0 +1,145 @@
+from __future__ import annotations
+
+import contextlib
+import functools
+import importlib.resources
+import os.path
+import shutil
+import tarfile
+from collections.abc import Generator
+from collections.abc import Sequence
+from typing import IO
+
+import pre_commit.constants as C
+from pre_commit import lang_base
+from pre_commit.envcontext import envcontext
+from pre_commit.envcontext import PatchesT
+from pre_commit.envcontext import UNSET
+from pre_commit.envcontext import Var
+from pre_commit.prefix import Prefix
+from pre_commit.util import CalledProcessError
+
+ENVIRONMENT_DIR = 'rbenv'
+health_check = lang_base.basic_health_check
+run_hook = lang_base.basic_run_hook
+
+
+def _resource_bytesio(filename: str) -> IO[bytes]:
+    files = importlib.resources.files('pre_commit.resources')
+    return files.joinpath(filename).open('rb')
+
+
+@functools.lru_cache(maxsize=1)
+def get_default_version() -> str:
+    if all(lang_base.exe_exists(exe) for exe in ('ruby', 'gem')):
+        return 'system'
+    else:
+        return C.DEFAULT
+
+
+def get_env_patch(
+        venv: str,
+        language_version: str,
+) -> PatchesT:
+    patches: PatchesT = (
+        ('GEM_HOME', os.path.join(venv, 'gems')),
+        ('GEM_PATH', UNSET),
+        ('BUNDLE_IGNORE_CONFIG', '1'),
+    )
+    if language_version == 'system':
+        patches += (
+            (
+                'PATH', (
+                    os.path.join(venv, 'gems', 'bin'), os.pathsep,
+                    Var('PATH'),
+                ),
+            ),
+        )
+    else:  # pragma: win32 no cover
+        patches += (
+            ('RBENV_ROOT', venv),
+            (
+                'PATH', (
+                    os.path.join(venv, 'gems', 'bin'), os.pathsep,
+                    os.path.join(venv, 'shims'), os.pathsep,
+                    os.path.join(venv, 'bin'), os.pathsep, Var('PATH'),
+                ),
+            ),
+        )
+    if language_version not in {'system', 'default'}:  # pragma: win32 no cover
+        patches += (('RBENV_VERSION', language_version),)
+
+    return patches
+
+
+@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, version)):
+        yield
+
+
+def _extract_resource(filename: str, dest: str) -> None:
+    with _resource_bytesio(filename) as bio:
+        with tarfile.open(fileobj=bio) as tf:
+            tf.extractall(dest)
+
+
+def _install_rbenv(
+        prefix: Prefix,
+        version: str,
+) -> None:  # pragma: win32 no cover
+    envdir = lang_base.environment_dir(prefix, ENVIRONMENT_DIR, version)
+
+    _extract_resource('rbenv.tar.gz', prefix.path('.'))
+    shutil.move(prefix.path('rbenv'), envdir)
+
+    # Only install ruby-build if the version is specified
+    if version != C.DEFAULT:
+        plugins_dir = os.path.join(envdir, 'plugins')
+        _extract_resource('ruby-download.tar.gz', plugins_dir)
+        _extract_resource('ruby-build.tar.gz', plugins_dir)
+
+
+def _install_ruby(
+        prefix: Prefix,
+        version: str,
+) -> None:  # pragma: win32 no cover
+    try:
+        lang_base.setup_cmd(prefix, ('rbenv', 'download', version))
+    except CalledProcessError:  # pragma: no cover (usually find with download)
+        # Failed to download from mirror for some reason, build it instead
+        lang_base.setup_cmd(prefix, ('rbenv', 'install', version))
+
+
+def install_environment(
+        prefix: Prefix, version: str, additional_dependencies: Sequence[str],
+) -> None:
+    envdir = lang_base.environment_dir(prefix, ENVIRONMENT_DIR, version)
+
+    if version != 'system':  # pragma: win32 no cover
+        _install_rbenv(prefix, version)
+        with in_env(prefix, version):
+            # Need to call this before installing so rbenv's directories
+            # are set up
+            lang_base.setup_cmd(prefix, ('rbenv', 'init', '-'))
+            if version != C.DEFAULT:
+                _install_ruby(prefix, version)
+            # Need to call this after installing to set up the shims
+            lang_base.setup_cmd(prefix, ('rbenv', 'rehash'))
+
+    with in_env(prefix, version):
+        lang_base.setup_cmd(
+            prefix, ('gem', 'build', *prefix.star('.gemspec')),
+        )
+        lang_base.setup_cmd(
+            prefix,
+            (
+                'gem', 'install',
+                '--no-document', '--no-format-executable',
+                '--no-user-install',
+                '--install-dir', os.path.join(envdir, 'gems'),
+                '--bindir', os.path.join(envdir, 'gems', 'bin'),
+                *prefix.star('.gem'), *additional_dependencies,
+            ),
+        )