Refactor JS escaping

This renames javascript.convert_js_arg() to javascript.to_js() and uses that
instead of string_escape() where possible.

qutebrowser/browser/pdfjs.py

@@ -99,10 +99,10 @@ def _generate_pdfjs_script(filename):
           }
 
           const viewer = window.PDFView || window.PDFViewerApplication;
-          viewer.open("{{ url }}");
+          viewer.open({{ url }});
         });
     """).render(
-        url=javascript.string_escape(url.toString(QUrl.FullyEncoded)),
+        url=javascript.to_js(url.toString(QUrl.FullyEncoded)),
         # WORKAROUND for https://bugreports.qt.io/browse/QTBUG-70420
         disable_create_object_url=(
             not qtutils.version_check('5.12') and

qutebrowser/browser/webkit/webkitelem.py

@@ -125,8 +125,8 @@ class WebKitElement(webelem.AbstractWebElement):
             self._elem.setPlainText(value)
         else:
             log.webelem.debug("Filling {!r} via javascript.".format(self))
-            value = javascript.string_escape(value)
-            self._elem.evaluateJavaScript("this.value='{}'".format(value))
+            value = javascript.to_js(value)
+            self._elem.evaluateJavaScript("this.value={}".format(value))
 
     def dispatch_event(self, event, bubbles=False,
                        cancelable=False, composed=False):
@@ -135,10 +135,10 @@ class WebKitElement(webelem.AbstractWebElement):
         self._elem.evaluateJavaScript(
             "this.dispatchEvent(new Event({}, "
             "{{'bubbles': {}, 'cancelable': {}, 'composed': {}}}))"
-            .format(javascript.convert_js_arg(event),
-                    javascript.convert_js_arg(bubbles),
-                    javascript.convert_js_arg(cancelable),
-                    javascript.convert_js_arg(composed)))
+            .format(javascript.to_js(event),
+                    javascript.to_js(bubbles),
+                    javascript.to_js(cancelable),
+                    javascript.to_js(composed)))
 
     def caret_position(self):
         """Get the text caret position for the current element."""
@@ -154,11 +154,11 @@ class WebKitElement(webelem.AbstractWebElement):
             raise webelem.Error("Element is not editable!")
         log.webelem.debug("Inserting text into element {!r}".format(self))
         self._elem.evaluateJavaScript("""
-            var text = "{}";
+            var text = {};
             var event = document.createEvent("TextEvent");
             event.initTextEvent("textInput", true, true, null, text);
             this.dispatchEvent(event);
-        """.format(javascript.string_escape(text)))
+        """.format(javascript.to_js(text)))
 
     def _parent(self):
         """Get the parent element of this element."""

qutebrowser/utils/javascript.py

@@ -49,7 +49,7 @@ def string_escape(text):
     return text
 
 
-def convert_js_arg(arg):
+def to_js(arg):
     """Convert the given argument so it's the equivalent in JS."""
     if arg is None:
         return 'undefined'
@@ -60,7 +60,7 @@ def convert_js_arg(arg):
     elif isinstance(arg, (int, float)):
         return str(arg)
     elif isinstance(arg, list):
-        return '[{}]'.format(', '.join(_convert_js_arg(e) for e in arg))
+        return '[{}]'.format(', '.join(to_js(e) for e in arg))
     else:
         raise TypeError("Don't know how to handle {!r} of type {}!".format(
             arg, type(arg).__name__))
@@ -68,7 +68,7 @@ def convert_js_arg(arg):
 
 def assemble(module, function, *args):
     """Assemble a javascript file and a function call."""
-    js_args = ', '.join(convert_js_arg(arg) for arg in args)
+    js_args = ', '.join(to_js(arg) for arg in args)
     if module == 'window':
         parts = ['window', function]
     else:

tests/unit/browser/test_pdfjs.py

@@ -45,8 +45,8 @@ def test_generate_pdfjs_page(available, snippet, monkeypatch):
 
 
 # Note that we got double protection, once because we use QUrl.FullyEncoded and
-# because we use qutebrowser.utils.javascript.string_escape.  Characters
-# like " are already replaced by QUrl.
+# because we use qutebrowser.utils.javascript.to_js. Characters like " are
+# already replaced by QUrl.
 @pytest.mark.parametrize('filename, expected', [
     ('foo.bar', "foo.bar"),
     ('foo"bar', "foo%22bar"),

tests/unit/javascript/stylesheet/test_stylesheet.py

@@ -62,9 +62,9 @@ class StylesheetTester:
         """Check whether the css in ELEMENT is set to VALUE."""
         self.js.run("console.log({document});"
                     "window.getComputedStyle({document}, null)"
-                    ".getPropertyValue('{prop}');".format(
+                    ".getPropertyValue({prop});".format(
                         document=document_element,
-                        prop=javascript.string_escape(css_style)),
+                        prop=javascript.to_js(css_style)),
                     value)
 
     def check_eq(self, one, two, true=True):

tests/unit/utils/test_javascript.py

@@ -86,12 +86,12 @@ class TestStringEscape:
     (True, 'true'),
     ([23, True, 'x'], '[23, true, "x"]'),
 ])
-def test_convert_js_arg(arg, expected):
+def test_to_js(arg, expected):
     if expected is TypeError:
         with pytest.raises(TypeError):
-            javascript.convert_js_arg(arg)
+            javascript.to_js(arg)
     else:
-        assert javascript.convert_js_arg(arg) == expected
+        assert javascript.to_js(arg) == expected
 
 
 @pytest.mark.parametrize('base, expected_base', [