Accept a name for --world with :jseval

doc/help/commands.asciidoc

@@ -447,7 +447,7 @@ Evaluate a JavaScript string.
 
 ==== optional arguments
 * +*-q*+, +*--quiet*+: Don't show resulting JS object.
-* +*-w*+, +*--world*+: Ignored on QtWebKit. On QtWebEngine, which JS world/context to run the snippet in.
+* +*-w*+, +*--world*+: Ignored on QtWebKit. On QtWebEngine, a world ID or name to run the snippet in.
 
 
 ==== note

qutebrowser/browser/commands.py

@@ -1918,14 +1918,15 @@ class CommandDispatcher:
 
     @cmdutils.register(instance='command-dispatcher', scope='window',
                        maxsplit=0, no_cmd_split=True)
-    def jseval(self, js_code, quiet=False, *, world: int=None):
+    def jseval(self, js_code, quiet=False, *,
+               world: typing.Union[usertypes.JsWorld, int]=None):
         """Evaluate a JavaScript string.
 
         Args:
             js_code: The string to evaluate.
             quiet: Don't show resulting JS object.
-            world: Ignored on QtWebKit. On QtWebEngine, a world ID to run the
-                   snippet in.
+            world: Ignored on QtWebKit. On QtWebEngine, a world ID or name to
+                   run the snippet in.
         """
         if quiet:
             jseval_cb = None

qutebrowser/browser/webengine/webenginetab.py

@@ -48,6 +48,14 @@ def init():
     req_interceptor.install(QWebEngineProfile.defaultProfile())
 
 
+# Mapping worlds from usertypes.JsWorld to QWebEngineScript world IDs.
+_JS_WORLD_MAP = {
+    usertypes.JsWorld.main: QWebEngineScript.MainWorld,
+    usertypes.JsWorld.application: QWebEngineScript.ApplicationWorld,
+    usertypes.JsWorld.user: QWebEngineScript.UserWorld,
+}
+
+
 class WebEnginePrinting(browsertab.AbstractPrinting):
 
     """QtWebEngine implementations related to printing."""
@@ -478,13 +486,11 @@ class WebEngineTab(browsertab.AbstractTab):
     def run_js_async(self, code, callback=None, *, world=None):
         if world is None:
             world_id = QWebEngineScript.ApplicationWorld
-        else:
-            # We need to make this sure here, as otherwise we get an unexpected
-            # TypeError later...
-            if not isinstance(world, int):
-                raise TypeError("Expected int as world id, got {!r}".format(
-                    world))
+        elif isinstance(world, int):
             world_id = world
+        else:
+            world_id = _JS_WORLD_MAP[world]
+
         try:
             if callback is None:
                 self._widget.page().runJavaScript(code, world_id)

qutebrowser/utils/usertypes.py

@@ -261,6 +261,10 @@ arg2backend = {
 }
 
 
+# JS world for QtWebEngine
+JsWorld = enum('JsWorld', ['main', 'application', 'user'])
+
+
 # Where a download should be saved
 class DownloadTarget:
 

tests/end2end/features/misc.feature

@@ -109,6 +109,13 @@ Feature: Various utility commands.
         And I run :jseval --world 0 do_log()
         Then the javascript message "Hello from the page!" should be logged
 
+    @qtwebkit_skip
+    Scenario: :jseval using the main world as name
+        When I set general -> log-javascript-console to info
+        And I open data/misc/jseval.html
+        And I run :jseval --world main do_log()
+        Then the javascript message "Hello from the page!" should be logged
+
     # :debug-webaction
 
     Scenario: :debug-webaction with valid value