Add tests for os_specific MergeDict modifier

Move platform lookup to utils and hab_base passes it to MergeDict

hab/merge_dict.py

@@ -8,10 +8,12 @@ def __init__(self, platform=None, **format_kwargs):
         self.format_kwargs = format_kwargs
         self.formatter = self.default_format
         self.pathsep = os.pathsep
-        # self.platform = platform
-        self.platform = 'windows'
         self.validator = None
 
+        if platform is None:
+            platform = utils.platform()
+        self.platform = platform
+
     def default_format(self, value):
         if isinstance(value, list):
             # Format the individual items if a list of args is used.

hab/parsers/hab_base.py

@@ -3,7 +3,6 @@
 import logging
 import os
 import subprocess
-import sys
 from pathlib import Path
 
 import anytree
@@ -81,7 +80,7 @@ def _platform(self):
         if self._platform_override:
             # Provide a method for testing to always test for running on a specific os
             return self._platform_override
-        return "windows" if sys.platform == "win32" else "linux"
+        return utils.platform()
 
     def check_environment(self, environment_config):
         """Check that the environment config only makes valid adjustments.
@@ -514,7 +513,7 @@ def update_environment(self, environment_config, obj=None):
             # No environment_config dictionary was set, noting to do
             return
 
-        merger = MergeDict(relative_root=self.dirname)
+        merger = MergeDict(relative_root=self.dirname, platform=self._platform)
         merger.formatter = obj.format_environment_value
         merger.validator = self.check_environment
         merger.update(self._environment, environment_config)

hab/utils.py

@@ -172,3 +172,8 @@ def load_json_file(filename):
 def path_forward_slash(path):
     """Converts a Path object into a string with forward slashes"""
     return str(path).replace('\\', '/')
+
+
+def platform():
+    """Returns the current operating system as `windows` or `linux`."""
+    return "windows" if sys.platform == "win32" else "linux"

tests/configs/not_set/os_env.json

@@ -0,0 +1,36 @@
+{
+    "name": "os",
+    "context": ["not_set"],
+    "environment": {
+        "os_specific": true,
+        "linux": {
+            "unset": [
+                "UNSET_VARIABLE_LIN"
+            ],
+            "set": {
+                "SET_VARIABLE_LIN": "set_value_lin"
+            },
+            "append": {
+                "APPEND_VARIABLE_LIN": "append_value_lin"
+            },
+            "prepend": {
+                "PREPEND_VARIABLE_LIN": "prepend_value_lin"
+            }
+        },
+        "windows": {
+            "unset": [
+                "UNSET_VARIABLE_WIN"
+            ],
+            "set": {
+                "SET_VARIABLE_WIN": "set_value_win"
+            },
+            "append": {
+                "APPEND_VARIABLE_WIN": "append_value_win"
+            },
+            "prepend": {
+                "PREPEND_VARIABLE_WIN": "prepend_value_win"
+            }
+        }
+    },
+    "inherits": false
+}

tests/site_os_specific.json

@@ -0,0 +1,23 @@
+{
+    "os_specific": true,
+    "linux": {
+        "append": {
+            "config_paths": [
+                "config/path"
+            ],
+            "distro_paths": [
+                "distro/path"
+            ]
+        }
+    },
+    "windows": {
+        "append": {
+            "config_paths": [
+                "config\\path"
+            ],
+            "distro_paths": [
+                "distro\\path"
+            ]
+        }
+    }
+}

tests/test_parsing.py

@@ -702,3 +702,29 @@ def test_duplicated_distros(config_root, resolver):
 
     with pytest.raises(DuplicateJsonError):
         resolver.find_distro("the_dcc==1.2")
+
+
+def test_os_specific_linux(monkeypatch, resolver):
+    """Check that if "os_specific" is set to true, only env vars for the current
+    os are resolved."""
+    # Simulate running on a linux platform.
+    monkeypatch.setattr(sys, "platform", "linux")
+    cfg = resolver.resolve("not_set/os")
+
+    assert cfg.environment["UNSET_VARIABLE_LIN"] is None
+    assert cfg.environment["SET_VARIABLE_LIN"] == ["set_value_lin"]
+    assert cfg.environment["APPEND_VARIABLE_LIN"] == ["append_value_lin"]
+    assert cfg.environment["PREPEND_VARIABLE_LIN"] == ["prepend_value_lin"]
+
+
+def test_os_specific_win(monkeypatch, resolver):
+    """Check that if "os_specific" is set to true, only env vars for the current
+    os are resolved."""
+    # Simulate running on a windows platform
+    monkeypatch.setattr(sys, "platform", "win32")
+    cfg = resolver.resolve("not_set/os")
+
+    assert cfg.environment["UNSET_VARIABLE_WIN"] is None
+    assert cfg.environment["SET_VARIABLE_WIN"] == ["set_value_win"]
+    assert cfg.environment["APPEND_VARIABLE_WIN"] == ["append_value_win"]
+    assert cfg.environment["PREPEND_VARIABLE_WIN"] == ["prepend_value_win"]

tests/test_resolver.py

@@ -113,7 +113,8 @@ def test_dump_forest(resolver):
             "    |-- hab.parsers.config.Config('not_set/env_path_set')",
             "    |-- hab.parsers.config.Config('not_set/env_path_unset')",
             "    |-- hab.parsers.config.Config('not_set/distros')",
-            "    +-- hab.parsers.config.Config('not_set/no_env')",
+            "    |-- hab.parsers.config.Config('not_set/no_env')",
+            "    +-- hab.parsers.config.Config('not_set/os')",
             "place-holder",
             "    hab.parsers.placeholder.Placeholder('place-holder')",
             "    |-- hab.parsers.config.Config('place-holder/child')",

tests/test_site.py

@@ -1,3 +1,5 @@
+import sys
+
 import colorama
 import pytest
 
@@ -78,3 +80,29 @@ def test_dump(config_root):
     result = site.dump()
     for check in checks:
         assert check.format(green="", reset="") in result
+
+
+def test_os_specific_linux(monkeypatch, config_root):
+    """Check that if "os_specific" is set to true, only vars for the current
+    os are resolved."""
+    # Simulate running on a linux platform.
+    monkeypatch.setattr(sys, "platform", "linux")
+
+    paths = [config_root / "site_os_specific.json"]
+    site = Site(paths)
+
+    assert site.get("config_paths") == ["config/path"]
+    assert site.get("distro_paths") == ["distro/path"]
+
+
+def test_os_specific_win(monkeypatch, config_root):
+    """Check that if "os_specific" is set to true, only vars for the current
+    os are resolved."""
+    # Simulate running on a windows platform
+    monkeypatch.setattr(sys, "platform", "win32")
+
+    paths = [config_root / "site_os_specific.json"]
+    site = Site(paths)
+
+    assert site.get("config_paths") == ["config\\path"]
+    assert site.get("distro_paths") == ["distro\\path"]