Add HTML tests to avoid regressions (#33)

Essentially, copy the HTML test approach
from the Sphinx project.

pyproject.toml

@@ -32,6 +32,8 @@ mypy = "^0.910"
 types-docutils = "^0.17.0"
 pep8-naming = "^0.13"
 coverage = "^6.5"
+lxml = "^4.9.2"
+lxml-stubs = "^0.4.0"
 
 [tool.poetry.group.dev.dependencies.isort]
 version = "^5.10"

test/conftest.py

@@ -0,0 +1,108 @@
+"""Test HTML output the same way that Sphinx does in test_build_html.py."""
+import re
+from itertools import chain, cycle
+from pathlib import Path
+from typing import Dict
+
+import pytest
+from docutils import nodes
+from lxml import etree as lxmltree
+from sphinx.testing.path import path as sphinx_path
+from sphinx.testing.util import SphinxTestApp
+
+pytest_plugins = "sphinx.testing.fixtures"
+
+etree_cache: Dict[str, str] = {}
+
+
+@pytest.fixture(scope='session')
+def rootdir():
+    return sphinx_path(__file__).parent.abspath() / 'roots'
+
+
+class SphinxBuilder:
+    def __init__(self, app: SphinxTestApp, src_path: Path):
+        self.app = app
+        self._src_path = src_path
+
+    @property
+    def src_path(self) -> Path:
+        return self._src_path
+
+    @property
+    def out_path(self) -> Path:
+        return Path(self.app.outdir)
+
+    def build(self, assert_pass=True):
+        self.app.build()
+        if assert_pass:
+            assert self.warnings == "", self.status
+        return self
+
+    @property
+    def status(self):
+        return self.app._status.getvalue()
+
+    @property
+    def warnings(self):
+        return self.app._warning.getvalue()
+
+    def get_doctree(self, docname: str, post_transforms: bool = False) -> nodes.document:
+        assert self.app.env is not None
+        doctree = self.app.env.get_doctree(docname)
+        if post_transforms:
+            self.app.env.apply_post_transforms(doctree, docname)
+        return doctree
+
+
+@pytest.fixture(scope='module')
+def cached_etree_parse():
+    def parse(fname):
+        if fname in etree_cache:
+            return etree_cache[fname]
+        with (fname).open('r') as fp:
+            data = fp.read().replace('\n', '')
+            etree = lxmltree.HTML(data)
+            etree_cache.clear()
+            etree_cache[fname] = etree
+            return etree
+
+    yield parse
+    etree_cache.clear()
+
+
+def flat_dict(d):
+    return chain.from_iterable([zip(cycle([fname]), values) for fname, values in d.items()])
+
+
+def check_xpath(etree, fname, path, check, be_found=True):
+    nodes = list(etree.xpath(path))
+    if check is None:
+        assert nodes == [], f'found any nodes matching xpath {path!r} in file {fname}'
+        return
+    else:
+        assert nodes != [], f'did not find any node matching xpath {path!r} in file {fname}'
+    if callable(check):
+        check(nodes)
+    elif not check:
+        # only check for node presence
+        pass
+    else:
+
+        def get_text(node):
+            if node.text is not None:
+                # the node has only one text
+                return node.text
+            else:
+                # the node has tags and text; gather texts just under the node
+                return ''.join(n.tail or '' for n in node)
+
+        rex = re.compile(check)
+        if be_found:
+            if any(rex.search(get_text(node)) for node in nodes):
+                return
+        else:
+            if all(not rex.search(get_text(node)) for node in nodes):
+                return
+
+        raise AssertionError(f'{check!r} not found in any node matching path {path} in {fname}: {[node.text for node in nodes]!r}')

test/roots/test-default-html/conf.py

@@ -0,0 +1 @@
+extensions = ["sphinxarg.ext"]

test/roots/test-default-html/index.rst

@@ -0,0 +1,7 @@
+Sample
+######
+
+.. argparse::
+   :filename: test/sample-directive-opts.py
+   :prog: sample-directive-opts
+   :func: get_parser

test/roots/test-default-html/subcommand-a.rst

@@ -0,0 +1,8 @@
+Command A
+=========
+
+.. argparse::
+   :filename: test/sample-directive-opts.py
+   :prog: sample-directive-opts
+   :func: get_parser
+   :path: A

test/sample-directive-opts.py

@@ -0,0 +1,21 @@
+import argparse
+
+
+def get_parser():
+    parser = argparse.ArgumentParser(prog='sample-directive-opts', description='Support SphinxArgParse HTML testing')
+    subparsers = parser.add_subparsers()
+    parser_a = subparsers.add_parser('A', help='A subparser')
+    parser_a.add_argument('baz', type=int, help='An integer')
+    parser_b = subparsers.add_parser('B', help='B subparser')
+    parser_b.add_argument('--barg', choices='XYZ', help='A list of choices')
+
+    parser.add_argument('--foo', help='foo help')
+    parser.add_argument('foo2', metavar='foo2 metavar', help='foo2 help')
+    grp1 = parser.add_argument_group('bar options')
+    grp1.add_argument('--bar', help='bar help')
+    grp1.add_argument('quux', help='quux help')
+    grp2 = parser.add_argument_group('bla options')
+    grp2.add_argument('--blah', help='blah help')
+    grp2.add_argument('sniggly', help='sniggly help')
+
+    return parser

test/test_default_html.py

@@ -0,0 +1,39 @@
+"""Test the HTML builder and check output against XPath."""
+
+import pytest
+
+from .conftest import check_xpath, flat_dict
+
+
+@pytest.mark.parametrize(
+    "fname,expect",
+    flat_dict(
+        {
+            'index.html': [
+                (".//h1", 'Sample'),
+                (".//h1", 'blah-blah', False),
+                (".//div[@class='highlight']//span", 'usage'),
+                (".//h2", 'Positional Arguments'),
+                (".//section[@id='positional-arguments']", ''),
+                (".//section[@id='positional-arguments']/dl/dt[1]/kbd", 'foo2 metavar'),
+                (".//section[@id='named-arguments']", ''),
+                (".//section[@id='named-arguments']/dl/dt[1]/kbd", '--foo'),
+                (".//section[@id='bar-options']", ''),
+                (".//section[@id='bar-options']/dl/dt[1]/kbd", '--bar'),
+            ],
+            'subcommand-a.html': [
+                (".//h1", 'Sample', False),
+                (".//h1", 'Command A'),
+                (".//div[@class='highlight']//span", 'usage'),
+                (".//h2", 'Positional Arguments'),
+                (".//section[@id='positional-arguments']", ''),
+                (".//section[@id='positional-arguments']/dl/dt[1]/kbd", 'baz'),
+            ],
+        }
+    ),
+)
+@pytest.mark.sphinx('html', testroot='default-html')
+def test_default_html(app, cached_etree_parse, fname, expect):
+    app.build()
+    print(app.outdir / fname)
+    check_xpath(cached_etree_parse(app.outdir / fname), fname, *expect)