Start adding tests for static replacement

common/djangoapps/static_replace/__init__.py

@@ -0,0 +1,103 @@
+import logging
+import re
+
+from staticfiles.storage import staticfiles_storage
+from staticfiles import finders
+from django.conf import settings
+
+from xmodule.modulestore.django import modulestore
+from xmodule.modulestore.xml import XMLModuleStore
+from xmodule.contentstore.content import StaticContent
+
+log = logging.getLogger(__name__)
+
+
+def _url_replace_regex(prefix):
+    return r"""
+        (?x)                 # flags=re.VERBOSE
+        (?P<quote>\\?['"])   # the opening quotes
+        (?P<prefix>{prefix}) # theeprefix
+        (?P<rest>.*?)        # everything else in the url
+        (?P=quote)           # the first matching closing quote
+        """.format(prefix=prefix)
+
+def try_staticfiles_lookup(path):
+    """
+    Try to lookup a path in staticfiles_storage.  If it fails, return
+    a dead link instead of raising an exception.
+    """
+    try:
+        url = staticfiles_storage.url(path)
+    except Exception as err:
+        log.warning("staticfiles_storage couldn't find path {0}: {1}".format(
+            path, str(err)))
+        # Just return the original path; don't kill everything.
+        url = path
+    return url
+
+
+def replace_course_urls(text, course_id):
+    """
+    Replace /course/$stuff urls with /courses/$course_id/$stuff urls
+
+    text: The text to replace
+    course_module: A CourseDescriptor
+
+    returns: text with the links replaced
+    """
+
+
+    def replace_course_url(match):
+        log.warning("Course match: %s", match.groupdict())
+        quote = match.group('quote')
+        rest = match.group('rest')
+        return "".join([quote, '/courses/' + course_id + '/', rest, quote])
+
+    return re.sub(_url_replace_regex('/course/'), replace_course_url, text)
+
+
+def replace_static_urls(text, data_directory, course_namespace=None):
+    """
+    Replace /static/$stuff urls either with their correct url as generated by collectstatic,
+    (/static/$md5_hashed_stuff) or by the course-specific content static url
+    /static/$course_data_dir/$stuff, or, if course_namespace is not None, by the
+    correct url in the contentstore (c4x://)
+
+    text: The source text to do the substitution in
+    data_directory: The directory in which course data is stored
+    course_namespace: The course identifier used to distinguish static content for this course in studio
+    """
+
+    def replace_static_url(match):
+        log.warning(match.groupdict())
+        quote = match.group('quote')
+        rest = match.group('rest')
+
+        # course_namespace is not None, then use studio style urls
+        if course_namespace is not None and not isinstance(modulestore(), XMLModuleStore):
+            url = StaticContent.convert_legacy_static_url(rest, course_namespace)
+            log.warning("From modulestore: %s", url)
+        # If we're in debug mode, and the file as requested exists, then don't change the links
+        elif (settings.DEBUG and finders.find(rest, True)):
+            url = match.group('prefix') + rest
+            log.warning("From finder: %s", url)
+        # Otherwise, look the file up in staticfiles_storage
+        else:
+            path = data_directory + '/' + rest
+            try:
+                url = staticfiles_storage.url(path)
+                log.warning("From staticfiles_storage: %s", url)
+            # And if that fails, return the path unmodified
+            except Exception as err:
+                log.warning("staticfiles_storage couldn't find path {0}: {1}".format(
+                    path, str(err)))
+                url = path
+                log.warning("Fallback: %s", url)
+        log.warning("".join([quote, url, quote]))
+        return "".join([quote, url, quote])
+
+    return re.sub(
+        _url_replace_regex('/static/(?!{data_dir})'.format(data_dir=data_directory)),
+        replace_static_url,
+        text
+    )

common/djangoapps/static_replace/test/test_static_replace.py

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+from nose.tools import assert_equals
+from static_replace import replace_static_urls, replace_course_urls
+
+DATA_DIRECTORY = 'data_dir'
+COURSE_ID = 'org/course/run'
+
+
+def test_multi_replace():
+    static_source = '"/static/file.png"'
+    course_source = '"/course/file.png"'
+
+    assert_equals(
+        replace_static_urls(static_source, DATA_DIRECTORY),
+        replace_static_urls(replace_static_urls(static_source, DATA_DIRECTORY), DATA_DIRECTORY)
+    )
+    assert_equals(
+        replace_course_urls(course_source, COURSE_ID),
+        replace_course_urls(replace_course_urls(course_source, COURSE_ID), COURSE_ID)
+    )
+    assert False