show config now shows all config, filter-able, contains host tox python and package versions (#1298)

and package versions

6 files changed, 215 insertions, 86 deletions

diff --git a/docs/changelog/1298.feature.rst b/docs/changelog/1298.feature.rst
new file mode 100644
index 00000000..1375c507
--- /dev/null
+++ b/docs/changelog/1298.feature.rst
@@ -0,0 +1,11 @@
+``--showconfig`` overhaul:
+
+- now fully generated via the config parser, so anyone can load it by using the built-in python config parser
+- the ``tox`` section contains all configuration data from config
+- the ``tox`` section contains a ``host_python`` key detailing the path of the host python
+- the ``tox:version`` section contains the versions of all packages tox depends on with their version
+- passing ``-l`` now allows only listing default target envs
+- allows showing config for a given set of tox environments only via the ``-e`` cli flag or the ``TOXENV`` environment
+  variable, in this case the ``tox`` and ``tox:version`` section is only shown if at least one verbosity flag is passed
+
+this should help inspecting the options.
diff --git a/src/tox/config/__init__.py b/src/tox/config/__init__.py
index 418cca9f..6551e0cd 100644
--- a/src/tox/config/__init__.py
+++ b/src/tox/config/__init__.py
@@ -392,7 +392,8 @@ def tox_addoption(parser):
     parser.add_argument(
         "--showconfig",
         action="store_true",
-        help="show configuration information for all environments. ",
+        help="show live configuration (by default all env, with -l only default targets,"
+        " specific via TOXENV/-e)",
     )
     parser.add_argument(
         "-l",
@@ -1077,7 +1078,8 @@ class ParseIni(object):
         self.handle_provision(config, reader)
 
         self.parse_build_isolation(config, reader)
-        config.envlist, all_envs, config.envlist_default = self._getenvdata(reader, config)
+        res = self._getenvdata(reader, config)
+        config.envlist, all_envs, config.envlist_default, config.envlist_explicit = res
 
         # factors used in config or predefined
         known_factors = self._list_section_factors("testenv")
@@ -1268,18 +1270,19 @@ class ParseIni(object):
         from_config = reader.getstring("envlist", replace=False)
 
         env_list = []
+        envlist_explicit = False
         if (from_option and "ALL" in from_option) or (
             not from_option and from_environ and "ALL" in from_environ.split(",")
         ):
             all_envs = self._getallenvs(reader)
         else:
             candidates = (
-                os.environ.get(PARALLEL_ENV_VAR_KEY),
-                from_option,
-                from_environ,
-                from_config,
+                (os.environ.get(PARALLEL_ENV_VAR_KEY), True),
+                (from_option, True),
+                (from_environ, True),
+                (from_config, False),
             )
-            env_str = next((i for i in candidates if i), [])
+            env_str, envlist_explicit = next(((i, e) for i, e in candidates if i), ([], False))
             env_list = _split_env(env_str)
             all_envs = self._getallenvs(reader, env_list)
 
@@ -1293,7 +1296,7 @@ class ParseIni(object):
         if config.isolated_build is True and package_env in env_list:
             msg = "isolated_build_env {} cannot be part of envlist".format(package_env)
             raise tox.exception.ConfigError(msg)
-        return env_list, all_envs, _split_env(from_config)
+        return env_list, all_envs, _split_env(from_config), envlist_explicit
 
 
 def _split_env(env):
@@ -1353,21 +1356,22 @@ class DepConfig:
         self.name = name
         self.indexserver = indexserver
 
-    def __str__(self):
+    def __repr__(self):
         if self.indexserver:
             if self.indexserver.name == "default":
                 return self.name
             return ":{}:{}".format(self.indexserver.name, self.name)
         return str(self.name)
 
-    __repr__ = __str__
-
 
 class IndexServerConfig:
     def __init__(self, name, url=None):
         self.name = name
         self.url = url
 
+    def __repr__(self):
+        return "IndexServerConfig(name={}, url={})".format(self.name, self.url)
+
 
 is_section_substitution = re.compile(r"{\[[^{}\s]+\]\S+?}").match
 """Check value matches substitution form of referencing value from other section.
diff --git a/src/tox/session/commands/show_config.py b/src/tox/session/commands/show_config.py
index d588ac80..f307cc18 100644
--- a/src/tox/session/commands/show_config.py
+++ b/src/tox/session/commands/show_config.py
@@ -1,31 +1,77 @@
-import subprocess
 import sys
+from collections import OrderedDict
 
-from tox import reporter as report
-from tox.version import __version__
+from six import StringIO
+from six.moves import configparser
+
+from tox import reporter
+
+DO_NOT_SHOW_CONFIG_ATTRIBUTES = (
+    "interpreters",
+    "envconfigs",
+    "envlist",
+    "pluginmanager",
+    "envlist_explicit",
+)
 
 
 def show_config(config):
-    info_versions()
-    report.keyvalue("config-file:", config.option.configfile)
-    report.keyvalue("toxinipath: ", config.toxinipath)
-    report.keyvalue("toxinidir:  ", config.toxinidir)
-    report.keyvalue("toxworkdir: ", config.toxworkdir)
-    report.keyvalue("setupdir:   ", config.setupdir)
-    report.keyvalue("distshare:  ", config.distshare)
-    report.keyvalue("skipsdist:  ", config.skipsdist)
-    report.line("")
-    for envconfig in config.envconfigs.values():
-        report.line("[testenv:{}]".format(envconfig.envname), bold=True)
-        for attr in config._parser._testenv_attr:
-            report.line("  {:<15} = {}".format(attr.name, getattr(envconfig, attr.name)))
-
-
-def info_versions():
-    versions = ["tox-{}".format(__version__)]
-    proc = subprocess.Popen(
-        (sys.executable, "-m", "virtualenv", "--version"), stdout=subprocess.PIPE
+    parser = configparser.ConfigParser()
+
+    if not config.envlist_explicit or reporter.verbosity() >= reporter.Verbosity.INFO:
+        tox_info(config, parser)
+        version_info(parser)
+    tox_envs_info(config, parser)
+
+    content = StringIO()
+    parser.write(content)
+    value = content.getvalue().rstrip()
+    reporter.verbosity0(value)
+
+
+def tox_envs_info(config, parser):
+    if config.envlist_explicit:
+        env_list = config.envlist
+    elif config.option.listenvs:
+        env_list = config.envlist_default
+    else:
+        env_list = list(config.envconfigs.keys())
+    for name in env_list:
+        env_config = config.envconfigs[name]
+        values = OrderedDict(
+            (attr.name, str(getattr(env_config, attr.name)))
+            for attr in config._parser._testenv_attr
+        )
+        section = "testenv:{}".format(name)
+        set_section(parser, section, values)
+
+
+def tox_info(config, parser):
+    info = OrderedDict(
+        (i, str(getattr(config, i)))
+        for i in sorted(dir(config))
+        if not i.startswith("_") and i not in DO_NOT_SHOW_CONFIG_ATTRIBUTES
     )
-    out, _ = proc.communicate()
-    versions.append("virtualenv-{}".format(out.decode("UTF-8").strip()))
-    report.keyvalue("tool-versions:", " ".join(versions))
+    info["host_python"] = sys.executable
+    set_section(parser, "tox", info)
+
+
+def version_info(parser):
+    import pkg_resources
+
+    versions = OrderedDict()
+    visited = set()
+    to_visit = {"tox"}
+    while to_visit:
+        current = to_visit.pop()
+        visited.add(current)
+        current_dist = pkg_resources.get_distribution(current)
+        to_visit.update(i.name for i in current_dist.requires() if i.name not in visited)
+        versions[current] = current_dist.version
+    set_section(parser, "tox:versions", versions)
+
+
+def set_section(parser, section, values):
+    parser.add_section(section)
+    for key, value in values.items():
+        parser.set(section, key, value)
diff --git a/tests/unit/config/test_config.py b/tests/unit/config/test_config.py
index c64ec1be..206fde8d 100644
--- a/tests/unit/config/test_config.py
+++ b/tests/unit/config/test_config.py
@@ -2722,12 +2722,6 @@ class TestCmdInvocation:
         assert "some-repr" in version_info
         assert "1.0" in version_info
 
-    def test_config_specific_ini(self, tmpdir, cmd):
-        ini = tmpdir.ensure("hello.ini")
-        result = cmd("-c", ini, "--showconfig")
-        assert not result.ret
-        assert result.outlines[1] == "config-file: {}".format(ini)
-
     def test_no_tox_ini(self, cmd, initproj):
         initproj("noini-0.5")
         result = cmd()
@@ -2736,49 +2730,6 @@ class TestCmdInvocation:
         assert result.err == msg
         assert not result.out
 
-    def test_override_workdir(self, cmd, initproj):
-        baddir = "badworkdir-123"
-        gooddir = "overridden-234"
-        initproj(
-            "overrideworkdir-0.5",
-            filedefs={
-                "tox.ini": """
-            [tox]
-            toxworkdir={}
-            """.format(
-                    baddir
-                )
-            },
-        )
-        result = cmd("--workdir", gooddir, "--showconfig")
-        assert not result.ret
-        assert gooddir in result.out
-        assert baddir not in result.out
-        assert py.path.local(gooddir).check()
-        assert not py.path.local(baddir).check()
-
-    def test_showconfig_with_force_dep_version(self, cmd, initproj):
-        initproj(
-            "force_dep_version",
-            filedefs={
-                "tox.ini": """
-            [tox]
-
-            [testenv]
-            deps=
-                dep1==2.3
-                dep2
-            """
-            },
-        )
-        result = cmd("--showconfig")
-        result.assert_success(is_run_test_env=False)
-        assert any(re.match(r".*deps.*dep1==2.3, dep2.*", l) for l in result.outlines)
-        # override dep1 specific version, and force version for dep2
-        result = cmd("--showconfig", "--force-dep=dep1", "--force-dep=dep2==5.0")
-        result.assert_success(is_run_test_env=False)
-        assert any(re.match(r".*deps.*dep1, dep2==5.0.*", l) for l in result.outlines)
-
 
 @pytest.mark.parametrize(
     "cli_args,run_envlist",
diff --git a/tests/unit/session/test_show_config.py b/tests/unit/session/test_show_config.py
new file mode 100644
index 00000000..1a01d1d8
--- /dev/null
+++ b/tests/unit/session/test_show_config.py
@@ -0,0 +1,117 @@
+import py
+import pytest
+from six import StringIO
+from six.moves import configparser
+
+
+def load_config(args, cmd):
+    result = cmd(*args)
+    result.assert_success(is_run_test_env=False)
+    parser = configparser.ConfigParser()
+    output = StringIO(result.out)
+    parser.readfp(output)
+    return parser
+
+
+def test_showconfig_with_force_dep_version(cmd, initproj):
+    initproj(
+        "force_dep_version",
+        filedefs={
+            "tox.ini": """
+        [tox]
+
+        [testenv]
+        deps=
+            dep1==2.3
+            dep2
+        """
+        },
+    )
+    parser = load_config(("--showconfig",), cmd)
+    assert parser.get("testenv:python", "deps") == "[dep1==2.3, dep2]"
+
+    parser = load_config(("--showconfig", "--force-dep=dep1", "--force-dep=dep2==5.0"), cmd)
+    assert parser.get("testenv:python", "deps") == "[dep1, dep2==5.0]"
+
+
+@pytest.fixture()
+def setup_mixed_conf(initproj):
+    initproj(
+        "force_dep_version",
+        filedefs={
+            "tox.ini": """
+            [tox]
+            envlist = py37,py27,pypi,docs
+
+            [testenv:notincluded]
+            changedir = whatever
+
+            [testenv:docs]
+            changedir = docs
+            """
+        },
+    )
+
+
+@pytest.mark.parametrize(
+    "args, expected",
+    [
+        (
+            ["--showconfig"],
+            [
+                "tox",
+                "tox:versions",
+                "testenv:py37",
+                "testenv:py27",
+                "testenv:pypi",
+                "testenv:docs",
+                "testenv:notincluded",
+            ],
+        ),
+        (
+            ["--showconfig", "-l"],
+            [
+                "tox",
+                "tox:versions",
+                "testenv:py37",
+                "testenv:py27",
+                "testenv:pypi",
+                "testenv:docs",
+            ],
+        ),
+        (["--showconfig", "-e", "py37,py36"], ["testenv:py37", "testenv:py36"]),
+    ],
+    ids=["all", "default_only", "-e"],
+)
+def test_showconfig(cmd, setup_mixed_conf, args, expected):
+    parser = load_config(args, cmd)
+    found_sections = parser.sections()
+    assert found_sections == expected
+
+
+def test_config_specific_ini(tmpdir, cmd):
+    ini = tmpdir.ensure("hello.ini")
+    output = load_config(("-c", ini, "--showconfig"), cmd)
+    assert output.get("tox", "toxinipath") == ini
+
+
+def test_override_workdir(cmd, initproj):
+    baddir = "badworkdir-123"
+    gooddir = "overridden-234"
+    initproj(
+        "overrideworkdir-0.5",
+        filedefs={
+            "tox.ini": """
+        [tox]
+        toxworkdir={}
+        """.format(
+                baddir
+            )
+        },
+    )
+    result = cmd("--workdir", gooddir, "--showconfig")
+    assert not result.ret
+    assert gooddir in result.out
+    assert baddir not in result.out
+    assert py.path.local(gooddir).check()
+    assert not py.path.local(baddir).check()
diff --git a/tox.ini b/tox.ini
index 02cab4c3..dc192ae0 100644
--- a/tox.ini
+++ b/tox.ini
@@ -20,7 +20,7 @@ setenv = PIP_DISABLE_VERSION_CHECK = 1
          COVERAGE_FILE = {env:COVERAGE_FILE:{toxworkdir}/.coverage.{envname}}
          VIRTUALENV_NO_DOWNLOAD = 1
 passenv = http_proxy https_proxy no_proxy SSL_CERT_FILE PYTEST_*
-deps = pip == 19.0.3
+deps = pip == 19.1.1
 extras = testing
 commands = pytest \
            --cov "{envsitepackagesdir}/tox" \