Bug 1619746 - Add --jsdebugger-path argument to mach test to specify …

…a custom binary for the toolbox r=gbrown,ochameau

Differential Revision: https://phabricator.services.mozilla.com/D65206

testing/mochitest/mochitest_options.py

@@ -393,6 +393,12 @@ class MochitestArguments(ArgumentContainer):
           "default": False,
           "help": "Start the browser JS debugger before running the test. Implies --no-autorun.",
           }],
+        [["--jsdebugger-path"],
+         {"default": None,
+          "dest": "jsdebuggerPath",
+          "help": "Path to a Firefox binary that will be used to run the toolbox. Should "
+                  "be used together with --jsdebugger."
+          }],
         [["--debug-on-failure"],
          {"action": "store_true",
           "default": False,
@@ -717,6 +723,10 @@ def validate(self, parser, options, context):
             parser.error(
                 "--debug-on-failure requires --jsdebugger.")
 
+        if options.jsdebuggerPath and not options.jsdebugger:
+            parser.error(
+                "--jsdebugger-path requires --jsdebugger.")
+
         if options.debuggerArgs and not options.debugger:
             parser.error(
                 "--debugger-args requires --debugger.")

testing/mochitest/runtests.py

@@ -2760,7 +2760,12 @@ def doTests(self, options, testsToFilter=None):
                 options.browserArgs.extend(['--jsconsole'])
 
             if options.jsdebugger:
-                options.browserArgs.extend(['-jsdebugger', '-wait-for-jsdebugger'])
+                options.browserArgs.extend(['-wait-for-jsdebugger', '-jsdebugger'])
+
+            # -jsdebugger takes a binary path as an optional argument.
+            # Append jsdebuggerPath right after `-jsdebugger`.
+            if options.jsdebuggerPath:
+                options.browserArgs.extend([options.jsdebuggerPath])
 
             # Remove the leak detection file so it can't "leak" to the tests run.
             # The file is not there if leak logging was not enabled in the