add toml support for ParamsDependency

dvc/dependency/param.py

@@ -2,6 +2,7 @@
 from collections import defaultdict
 
 import dpath.util
+import toml
 import yaml
 from voluptuous import Any
 
@@ -21,6 +22,8 @@ class ParamsDependency(LocalDependency):
     PARAM_PARAMS = "params"
     PARAM_SCHEMA = {PARAM_PARAMS: Any(dict, list, None)}
     DEFAULT_PARAMS_FILE = "params.yaml"
+    PARAMS_FILE_LOADERS = defaultdict(lambda: yaml.safe_load)
+    PARAMS_FILE_LOADERS.update({".toml": toml.load})
 
     def __init__(self, stage, path, params):
         info = {}
@@ -87,8 +90,10 @@ def read_params(self):
 
         with self.repo.tree.open(self.path_info, "r") as fobj:
             try:
-                config = yaml.safe_load(fobj)
-            except yaml.YAMLError as exc:
+                config = self.PARAMS_FILE_LOADERS[
+                    self.path_info.suffix.lower()
+                ](fobj)
+            except (yaml.YAMLError, toml.TomlDecodeError) as exc:
                 raise BadParamFileError(
                     f"Unable to read parameters from '{self}'"
                 ) from exc

dvc/repo/params/show.py

@@ -1,5 +1,6 @@
 import logging
 
+import toml
 import yaml
 
 from dvc.dependency.param import ParamsDependency
@@ -34,8 +35,10 @@ def _read_params(repo, configs, rev):
 
         with repo.tree.open(config, "r") as fobj:
             try:
-                res[str(config)] = yaml.safe_load(fobj)
-            except yaml.YAMLError:
+                res[str(config)] = ParamsDependency.PARAMS_FILE_LOADERS[
+                    config.suffix.lower()
+                ](fobj)
+            except (yaml.YAMLError, toml.TomlDecodeError):
                 logger.debug(
                     "failed to read '%s' on '%s'", config, rev, exc_info=True
                 )

setup.cfg

@@ -17,7 +17,7 @@ count=true
 [isort]
 include_trailing_comma=true
 known_first_party=dvc,tests
-known_third_party=PyInstaller,RangeHTTPServer,boto3,colorama,configobj,distro,dpath,flaky,flufl,funcy,git,grandalf,mock,moto,nanotime,networkx,packaging,pathspec,pygtrie,pylint,pytest,requests,ruamel,setuptools,shortuuid,shtab,tqdm,voluptuous,yaml,zc
+known_third_party=PyInstaller,RangeHTTPServer,boto3,colorama,configobj,distro,dpath,flaky,flufl,funcy,git,grandalf,mock,moto,nanotime,networkx,packaging,pathspec,pygtrie,pylint,pytest,requests,ruamel,setuptools,shortuuid,shtab,toml,tqdm,voluptuous,yaml,zc
 line_length=79
 force_grid_wrap=0
 use_parentheses=True

setup.py

@@ -62,6 +62,7 @@ def run(self):
     "appdirs>=1.4.3",
     "PyYAML>=5.1.2,<5.4",  # Compatibility with awscli
     "ruamel.yaml>=0.16.1",
+    "toml>=0.10.1",
     "funcy>=1.14",
     "pathspec>=0.6.0",
     "shortuuid>=0.5.0",

tests/func/params/test_show.py

@@ -14,6 +14,16 @@ def test_show(tmp_dir, dvc):
     assert dvc.params.show() == {"": {"params.yaml": {"foo": "bar"}}}
 
 
+def test_show_toml(tmp_dir, dvc):
+    tmp_dir.gen("params.toml", "[foo]\nbar = 42\nbaz = [1, 2]\n")
+    dvc.run(
+        cmd="echo params.toml", params=["params.toml:foo"], single_stage=True
+    )
+    assert dvc.params.show() == {
+        "": {"params.toml": {"foo": {"bar": 42, "baz": [1, 2]}}}
+    }
+
+
 def test_show_multiple(tmp_dir, dvc):
     tmp_dir.gen("params.yaml", "foo: bar\nbaz: qux\n")
     dvc.run(

tests/unit/dependency/test_params.py

@@ -1,4 +1,5 @@
 import pytest
+import toml
 import yaml
 
 from dvc.dependency import ParamsDependency, loadd_from, loads_params
@@ -99,6 +100,37 @@ def test_read_params_nested(tmp_dir, dvc):
     assert dep.read_params() == {"some.path.foo": ["val1", "val2"]}
 
 
+def test_read_params_default_loader(tmp_dir, dvc):
+    parameters_file = "parameters.foo"
+    tmp_dir.gen(
+        parameters_file,
+        yaml.dump({"some": {"path": {"foo": ["val1", "val2"]}}}),
+    )
+    dep = ParamsDependency(Stage(dvc), parameters_file, ["some.path.foo"])
+    assert dep.read_params() == {"some.path.foo": ["val1", "val2"]}
+
+
+def test_read_params_wrong_suffix(tmp_dir, dvc):
+    parameters_file = "parameters.toml"
+    tmp_dir.gen(
+        parameters_file,
+        yaml.dump({"some": {"path": {"foo": ["val1", "val2"]}}}),
+    )
+    dep = ParamsDependency(Stage(dvc), parameters_file, ["some.path.foo"])
+    with pytest.raises(BadParamFileError):
+        dep.read_params()
+
+
+def test_read_params_toml(tmp_dir, dvc):
+    parameters_file = "parameters.toml"
+    tmp_dir.gen(
+        parameters_file,
+        toml.dumps({"some": {"path": {"foo": ["val1", "val2"]}}}),
+    )
+    dep = ParamsDependency(Stage(dvc), parameters_file, ["some.path.foo"])
+    assert dep.read_params() == {"some.path.foo": ["val1", "val2"]}
+
+
 def test_save_info_missing_config(dvc):
     dep = ParamsDependency(Stage(dvc), None, ["foo"])
     with pytest.raises(MissingParamsError):