1 files changed, 77 insertions, 0 deletions
diff --git a/pre_commit/languages/conda.py b/pre_commit/languages/conda.py
new file mode 100644
index 0000000..80b3e15
--- /dev/null
+++ b/pre_commit/languages/conda.py
@@ -0,0 +1,77 @@
+from __future__ import annotations
+
+import contextlib
+import os
+import sys
+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 SubstitutionT
+from pre_commit.envcontext import UNSET
+from pre_commit.envcontext import Var
+from pre_commit.prefix import Prefix
+from pre_commit.util import cmd_output_b
+
+ENVIRONMENT_DIR = 'conda'
+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(env: str) -> PatchesT:
+    # On non-windows systems executable live in $CONDA_PREFIX/bin, on Windows
+    # they can be in $CONDA_PREFIX/bin, $CONDA_PREFIX/Library/bin,
+    # $CONDA_PREFIX/Scripts and $CONDA_PREFIX. Whereas the latter only
+    # seems to be used for python.exe.
+    path: SubstitutionT = (os.path.join(env, 'bin'), os.pathsep, Var('PATH'))
+    if sys.platform == 'win32':  # pragma: win32 cover
+        path = (env, os.pathsep, *path)
+        path = (os.path.join(env, 'Scripts'), os.pathsep, *path)
+        path = (os.path.join(env, 'Library', 'bin'), os.pathsep, *path)
+
+    return (
+        ('PYTHONHOME', UNSET),
+        ('VIRTUAL_ENV', UNSET),
+        ('CONDA_PREFIX', env),
+        ('PATH', 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
+
+
+def _conda_exe() -> str:
+    if os.environ.get('PRE_COMMIT_USE_MICROMAMBA'):
+        return 'micromamba'
+    elif os.environ.get('PRE_COMMIT_USE_MAMBA'):
+        return 'mamba'
+    else:
+        return 'conda'
+
+
+def install_environment(
+        prefix: Prefix,
+        version: str,
+        additional_dependencies: Sequence[str],
+) -> None:
+    lang_base.assert_version_default('conda', version)
+
+    conda_exe = _conda_exe()
+
+    env_dir = lang_base.environment_dir(prefix, ENVIRONMENT_DIR, version)
+    cmd_output_b(
+        conda_exe, 'env', 'create', '-p', env_dir, '--file',
+        'environment.yml', cwd=prefix.prefix_dir,
+    )
+    if additional_dependencies:
+        cmd_output_b(
+            conda_exe, 'install', '-p', env_dir, *additional_dependencies,
+            cwd=prefix.prefix_dir,
+        )