fix browser addon on Windows

mitmproxy/addons/browser.py

@@ -1,15 +1,27 @@
+import shutil
 import subprocess
-import sys
 import tempfile
+import typing
 
 from mitmproxy import command
 from mitmproxy import ctx
 
-platformPaths = {
-    "linux": "google-chrome",
-    "win32": "chrome.exe",
-    "darwin": "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome",
-}
+
+def get_chrome_executable() -> typing.Optional[str]:
+    for browser in (
+            "/Applications/Google Chrome.app/Contents/MacOS/Google Chrome",
+            # https://stackoverflow.com/questions/40674914/google-chrome-path-in-windows-10
+            r"C:\Program Files (x86)\Google\Chrome\Application\chrome.exe",
+            r"C:\Program Files (x86)\Google\Application\chrome.exe",
+            # Linux binary names from Python's webbrowser module.
+            "google-chrome",
+            "chrome",
+            "chromium",
+            "chromium-browser",
+    ):
+        if shutil.which(browser):
+            return browser
+    return None
 
 
 class Browser:
@@ -29,8 +41,8 @@ class Browser:
             else:
                 self.done()
 
-        cmd = platformPaths.get(sys.platform)
-        if not cmd:  # pragma: no cover
+        cmd = get_chrome_executable()
+        if not cmd:
             ctx.log.alert("Your platform is not supported yet - please submit a patch.")
             return
 
@@ -59,4 +71,4 @@ class Browser:
             self.browser.kill()
             self.tdir.cleanup()
         self.browser = None
-        self.tdir = None
+        self.tdir = None

test/mitmproxy/addons/test_browser.py

@@ -5,7 +5,8 @@ from mitmproxy.test import taddons
 
 
 def test_browser():
-    with mock.patch("subprocess.Popen") as po:
+    with mock.patch("subprocess.Popen") as po, mock.patch("shutil.which") as which:
+        which.return_value = "chrome"
         b = browser.Browser()
         with taddons.context() as tctx:
             b.start()
@@ -18,3 +19,13 @@ def test_browser():
             assert tctx.master.has_log("already running")
             b.done()
             assert not b.browser
+
+
+def test_no_browser():
+    with mock.patch("shutil.which") as which:
+        which.return_value = False
+
+        b = browser.Browser()
+        with taddons.context() as tctx:
+            b.start()
+            assert tctx.master.has_log("platform is not supported")