webdriver: refactor document inlining helper; #webdriver

andreastt · jgraham · commit 6fdb04a045f8 · 2019-08-07T21:20:55.000+01:00
The inline() function has a bug where the mime keyword argument is ignored: if the doctype is recognised, the media type is overridden with the default for that document type. This patch's primary motivation is to fix that bug, so that the media type may be configured individually from the document type. The result of this ended in a larger refactoring of the inlining helper so that the character set may also be individually configured. The result of the combined changes is hopefully that the code is easier to understand, along with its new documentation. bugzilla-url: https://bugzilla.mozilla.org/show_bug.cgi?id=1570302 gecko-commit: e595a5b014135c515721b20d39176a70d1a09839 gecko-integration-branch: mozilla-inbound
diff --git a/webdriver/tests/support/inline.py b/webdriver/tests/support/inline.py
@@ -1,54 +1,89 @@
-import urllib
+"""Helpers for inlining extracts of documents in tests."""
 
+import urllib
 
-def inline(doc,
-           doctype="html",
-           mime="text/html;charset=utf-8",
-           **kwargs):
-    from .fixtures import server_config, url
-    build_url = url(server_config())
 
-    if doctype == "html":
-        mime = "text/html;charset=utf-8"
-    elif doctype == "xhtml":
-        mime = "application/xhtml+xml"
-        doc = """<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
+BOILERPLATES = {
+    "html": "<!doctype html>\n<meta charset={charset}>\n{src}",
+    "xhtml": """<!DOCTYPE html PUBLIC "-//W3C//DTD XHTML 1.0 Strict//EN"
     "http://www.w3.org/TR/xhtml1/DTD/xhtml1-strict.dtd">
 <html xmlns="http://www.w3.org/1999/xhtml" xml:lang="en" lang="en">
   <head>
     <title>XHTML might be the future</title>
   </head>
 
   <body>
-    {}
+    {src}
   </body>
-</html>""".format(doc)
-    elif doctype == "xml":
-        mime = "text/xml"
-        doc = """<?xml version="1.0" encoding="UTF-8"?>{}""".format(doc)
+</html>""",
+    "xml": """<?xml version="1.0" encoding="{charset}"?>\n{src}""",
+}
+MIME_TYPES = {
+    "html": "text/html",
+    "xhtml": "application/xhtml+xml",
+    "xml": "text/xml",
+}
 
-    query = {"doc": doc}
-    if mime != "text/html;charset=utf8":
-        query["content-type"] = mime
+def inline(src, doctype="html", mime=None, charset=None, **kwargs):
+    """
+    Takes a source extract and produces well-formed documents.
 
-    return build_url("/webdriver/tests/support/inline.py",
-                     query=urllib.urlencode(query),
-                     **kwargs)
+    Based on the desired document type, the extract is embedded with
+    predefined boilerplate in order to produce well-formed documents.
+    The media type and character set may also be individually configured.
 
+    This helper function originally used data URLs, but since these
+    are not universally supported (or indeed standardised!) across
+    browsers, it now delegates the serving of the document to wptserve.
+    This file also acts as a wptserve handler (see the main function
+    below) which configures the HTTP response using query parameters.
+
+    This function returns a URL to the wptserve handler, which in turn
+    will serve an HTTP response with the requested source extract
+    inlined in a well-formed document, and the Content-Type header
+    optionally configured using the desired media type and character set.
+
+    Any additional keyword arguments are passed on to the build_url
+    function.
+    """
+    from .fixtures import server_config, url
+    build_url = url(server_config())
 
-def iframe(doc, **kwargs):
-    return "<iframe src='%s'></iframe>" % inline(doc, **kwargs)
+    if mime is None:
+        mime = MIME_TYPES[doctype]
+    if charset is None:
+        charset = "UTF-8"
+    doc = BOILERPLATES[doctype].format(charset=charset, src=src)
+
+    query = {"doc": doc, "mime": mime, "charset": charset}
+    return build_url(
+        "/webdriver/tests/support/inline.py",
+        query=urllib.urlencode(query),
+        **kwargs)
+
+
+def iframe(src, **kwargs):
+    """Inlines document extract as the source document of an <iframe>."""
+    return "<iframe src='{}'></iframe>".format(inline(src, **kwargs))
 
 
 def main(request, response):
     doc = request.GET.first("doc", None)
-    content_type = request.GET.first("content-type", "text/html;charset=utf8")
+    mime = request.GET.first("mime", None)
+    charset = request.GET.first("charset", None)
+
     if doc is None:
-        rv = 404, [("Content-Type", "text/plain")], "Missing doc parameter in query"
-    else:
-        response.headers.update([
-            ("Content-Type", content_type),
-            ("X-XSS-Protection", "0")
-        ])
-        rv = doc
-    return rv
+        return 404, [("Content-Type",
+                      "text/plain")], "Missing doc parameter in query"
+
+    content_type = []
+    if mime is not None:
+        content_type.append(mime)
+    if charset is not None:
+        content_type.append("charset={}".format(charset))
+
+    headers = {"X-XSS-Protection": "0"}
+    if len(content_type) > 0:
+        headers["Content-Type"] = ";".join(content_type)
+
+    return 200, headers.items(), doc
