Make it possible to set sequence options (#4210)

* Make it possible to set sequence options

Attempts to fix #3015 through looking at whether or not the option is
of the type Sequence[str].

Treat all deferred options as potentially Sequence options, by making the
deferred dict values a list.

* Add full test coverage to optmanager again

* Document how to set sequence options

* minor improvements

* update changelog

Co-authored-by: Maximilian Hils <git@maximilianhils.com>

CHANGELOG.md

@@ -67,6 +67,7 @@ Mitmproxy has a completely new proxy core, fixing many longstanding issues:
   (@mhils)
 * `json()` method for HTTP Request and Response instances will return decoded JSON body. (@rbdixon)
 * Support for HTTP/2 Push Promises has been dropped. (@mhils)
+* Make it possible to set sequence options from the command line (@Yopi)
 * --- TODO: add new PRs above this line ---
 * ... and various other fixes, documentation improvements, dependency version bumps, etc.
 

mitmproxy/addons/core.py

@@ -56,6 +56,8 @@ class Core:
             strings and integers are set to None (if permitted), and sequences
             are emptied. Boolean values can be true, false or toggle.
             Multiple values are concatenated with a single space.
+            Sequences are set using multiple invocations to set for
+            the same option.
         """
         strspec = f"{option}={value}"
         try:

mitmproxy/optmanager.py

@@ -1,3 +1,4 @@
+import collections
 import contextlib
 import blinker
 import blinker._saferef
@@ -91,7 +92,7 @@ class OptManager:
         mutation doesn't change the option state inadvertently.
     """
     def __init__(self):
-        self.deferred: typing.Dict[str, str] = {}
+        self.deferred: typing.Dict[str, typing.List[str]] = {}
         self.changed = blinker.Signal()
         self.errored = blinker.Signal()
         # Options must be the last attribute here - after that, we raise an
@@ -295,7 +296,7 @@ class OptManager:
             are added.
         """
         vals = {}
-        unknown = {}
+        unknown: typing.Dict[str, typing.List[str]] = collections.defaultdict(list)
         for i in spec:
             parts = i.split("=", maxsplit=1)
             if len(parts) == 1:
@@ -303,9 +304,9 @@ class OptManager:
             else:
                 optname, optval = parts[0], parts[1]
             if optname in self._options:
-                vals[optname] = self.parse_setval(self._options[optname], optval)
+                vals[optname] = self.parse_setval(self._options[optname], optval, vals.get(optname))
             else:
-                unknown[optname] = optval
+                unknown[optname].append(optval)
         if defer:
             self.deferred.update(unknown)
         elif unknown:
@@ -318,15 +319,16 @@ class OptManager:
             have since been added.
         """
         update = {}
-        for optname, optval in self.deferred.items():
+        for optname, optvals in self.deferred.items():
             if optname in self._options:
-                optval = self.parse_setval(self._options[optname], optval)
-                update[optname] = optval
+                for optval in optvals:
+                    optval = self.parse_setval(self._options[optname], optval, update.get(optname))
+                    update[optname] = optval
         self.update(**update)
         for k in update.keys():
             del self.deferred[k]
 
-    def parse_setval(self, o: _Option, optstr: typing.Optional[str]) -> typing.Any:
+    def parse_setval(self, o: _Option, optstr: typing.Optional[str], currentvalue: typing.Any) -> typing.Any:
         """
             Convert a string to a value appropriate for the option type.
         """
@@ -357,7 +359,10 @@ class OptManager:
             if not optstr:
                 return []
             else:
-                return getattr(self, o.name) + [optstr]
+                if currentvalue:
+                    return getattr(self, o.name) + currentvalue + [optstr]
+                else:
+                    return getattr(self, o.name) + [optstr]
         raise NotImplementedError("Unsupported option type: %s", o.typespec)
 
     def make_parser(self, parser, optname, metavar=None, short=None):

mitmproxy/tools/cmdline.py

@@ -27,6 +27,8 @@ def common_options(parser, opts):
             Set an option. When the value is omitted, booleans are set to true,
             strings and integers are set to None (if permitted), and sequences
             are emptied. Boolean values can be true, false or toggle.
+            Sequences are set using multiple invocations to set for
+            the same option.
         """
     )
     parser.add_argument(

test/mitmproxy/test_optmanager.py

@@ -71,7 +71,7 @@ def test_defaults():
 def test_required_int():
     o = TO()
     with pytest.raises(exceptions.OptionsError):
-        o.parse_setval(o._options["required_int"], None)
+        o.parse_setval(o._options["required_int"], None, None)
 
 
 def test_deepcopy():
@@ -439,6 +439,9 @@ def test_set():
     opts.set("seqstr")
     assert opts.seqstr == []
 
+    opts.set(*('seqstr=foo', 'seqstr=bar'))
+    assert opts.seqstr == ["foo", "bar"]
+
     with pytest.raises(exceptions.OptionsError):
         opts.set("deferredoption=wobble")
 
@@ -450,3 +453,12 @@ def test_set():
     opts.process_deferred()
     assert "deferredoption" not in opts.deferred
     assert opts.deferredoption == "wobble"
+
+    opts.set(*('deferredsequenceoption=a', 'deferredsequenceoption=b'), defer=True)
+    assert "deferredsequenceoption" in opts.deferred
+    opts.process_deferred()
+    assert "deferredsequenceoption" in opts.deferred
+    opts.add_option("deferredsequenceoption", typing.Sequence[str], [], "help")
+    opts.process_deferred()
+    assert "deferredsequenceoption" not in opts.deferred
+    assert opts.deferredsequenceoption == ["a", "b"]