Consolidate tox environments (#328)

.travis.yml

@@ -27,10 +27,6 @@ jobs:
       python: 3.6
       env: TOXENV=py36
 
-    -
-      python: 3.6
-      env: TOXENV=py36-ansi2html
-
     -
       python: 3.7
       dist: xenial
@@ -41,29 +37,15 @@ jobs:
       python: 3.8
       env: TOXENV=py38
 
-    -
-      python: 3.7
-      dist: xenial
-      sudo: required
-      env: TOXENV=py37-ansi2html
-
     - name: devel
       python: 3.8
       dist: xenial
       env: TOXENV=devel
 
-    -
-      python: 3.8
-      env: TOXENV=py38-ansi2html
-
     -
       python: pypy3
       env: TOXENV=pypy3
 
-    -
-      python: pypy3
-      env: TOXENV=pypy3-ansi2html
-
     - stage: deploy
       python: 3.7
       dist: xenial

pytest_html/plugin.py

@@ -4,6 +4,8 @@
 
 from base64 import b64encode, b64decode
 from collections import OrderedDict
+from functools import lru_cache
+import importlib
 from os.path import isfile
 import datetime
 import json
@@ -17,14 +19,6 @@ import re
 from html import escape
 import pytest
 
-try:
-    from ansi2html import Ansi2HTMLConverter, style
-
-    ANSI = True
-except ImportError:
-    # ansi2html is not installed
-    ANSI = False
-
 from py.xml import html, raw
 
 from . import extras
@@ -33,6 +27,16 @@ from . import __version__, __pypi_url__
 from _pytest.logging import _remove_ansi_escape_sequences
 
 
+@lru_cache()
+def ansi_support():
+    try:
+        # from ansi2html import Ansi2HTMLConverter, style  # NOQA
+        return importlib.import_module("ansi2html")
+    except ImportError:
+        # ansi2html is not installed
+        pass
+
+
 def pytest_addhooks(pluginmanager):
     from . import hooks
 
@@ -290,8 +294,10 @@ class HTMLReport:
                 log.append(f" {header:-^80} ")
                 log.append(html.br())
 
-                if ANSI:
-                    converter = Ansi2HTMLConverter(inline=False, escaped=False)
+                if ansi_support():
+                    converter = ansi_support().Ansi2HTMLConverter(
+                        inline=False, escaped=False
+                    )
                     content = converter.convert(content, full=False)
                 else:
                     content = _remove_ansi_escape_sequences(content)
@@ -413,13 +419,13 @@ class HTMLReport:
             __name__, os.path.join("resources", "style.css")
         ).decode("utf-8")
 
-        if ANSI:
+        if ansi_support():
             ansi_css = [
                 "\n/******************************",
                 " * ANSI2HTML STYLES",
                 " ******************************/\n",
             ]
-            ansi_css.extend([str(r) for r in style.get_styles()])
+            ansi_css.extend([str(r) for r in ansi_support().style.get_styles()])
             self.style_css += "\n".join(ansi_css)
 
         # <DF> Add user-provided CSS

testing/test_pytest_html.py

@@ -809,14 +809,14 @@ class TestHTML:
         assert result.ret == 0
         assert_results(html, passed=1)
 
-    def test_ansi_color(self, testdir):
-        try:
-            import ansi2html  # NOQA
+    @pytest.mark.parametrize(
+        "with_ansi", [True, False],
+    )
+    def test_ansi_color(self, testdir, mocker, with_ansi):
+        if not with_ansi:
+            mock_ansi_support = mocker.patch("pytest_html.plugin.ansi_support")
+            mock_ansi_support.return_value = None
 
-            ANSI = True
-        except ImportError:
-            # ansi2html is not installed
-            ANSI = False
         pass_content = [
             '<span class="ansi31">RCOLOR',
             '<span class="ansi32">GCOLOR',
@@ -834,7 +834,7 @@ class TestHTML:
         result, html = run(testdir, "report.html", "--self-contained-html")
         assert result.ret == 0
         for content in pass_content:
-            if ANSI:
+            if with_ansi:
                 assert content in html
             else:
                 assert content not in html

tox.ini

@@ -1,10 +1,10 @@
-# Tox (http://tox.testrun.org/) is a tool for running tests
+# Tox (https://tox.readthedocs.io) is a tool for running tests
 # in multiple virtualenvs. This configuration file will run the
 # test suite on all supported python versions. To use it, "pip install tox"
 # and then run "tox" from this directory.
 
 [tox]
-envlist = py{36,37,38,py3}{,-ansi2html}, linting
+envlist = py{36,37,38,py3}, linting
 
 [testenv]
 setenv = PYTHONDONTWRITEBYTECODE=1
@@ -12,7 +12,7 @@ deps =
     pytest-xdist
     pytest-rerunfailures
     pytest-mock
-    py{36,37,38,py3}-ansi2html: ansi2html
+    ansi2html  # soft-dependency
 commands = pytest -v -r a --color=yes --html={envlogdir}/report.html --self-contained-html {posargs}
 
 [testenv:linting]