Bug 1550518 - Add --headless support for xpcshell-test. r=gbrown

Entries in the xpcshell.ini manifest override the default specified on the command line.

Differential Revision: https://phabricator.services.mozilla.com/D70166

--HG--
extra : moz-landing-system : lando

testing/xpcshell/runxpcshelltests.py

@@ -161,6 +161,7 @@ class XPCShellTestThread(Thread):
         self.interactive = kwargs.get('interactive')
         self.prefsFile = kwargs.get('prefsFile')
         self.verboseIfFails = kwargs.get('verboseIfFails')
+        self.headless = kwargs.get('headless')
 
         # only one of these will be set to 1. adding them to the totals in
         # the harness
@@ -682,7 +683,7 @@ class XPCShellTestThread(Thread):
         if self.test_object.get('subprocess') == 'true':
             self.env['PYTHON'] = sys.executable
 
-        if self.test_object.get('headless', False):
+        if self.test_object.get('headless', 'true' if self.headless else None) == 'true':
             self.env["MOZ_HEADLESS"] = '1'
             self.env["DISPLAY"] = '77'  # Set a fake display.
 
@@ -1397,6 +1398,7 @@ class XPCShellTests(object):
         self.threadCount = options.get('threadCount') or NUM_THREADS
         self.jscovdir = options.get('jscovdir')
         self.enable_webrender = options.get('enable_webrender')
+        self.headless = options.get('headless')
 
         self.testCount = 0
         self.passCount = 0
@@ -1485,6 +1487,7 @@ class XPCShellTests(object):
             'app_dir_key': appDirKey,
             'prefsFile': self.prefsFile,
             'verboseIfFails': self.verboseIfFails,
+            'headless': self.headless,
         }
 
         if self.sequential:

testing/xpcshell/selftest.py

@@ -459,6 +459,26 @@ add_test(function test_child_mozinfo () {
 });
 '''
 
+HEADLESS_TRUE = '''
+add_task(function headless_true() {
+  let env = Cc["@mozilla.org/process/environment;1"].getService(
+    Ci.nsIEnvironment
+  );
+  Assert.equal(env.get("MOZ_HEADLESS"), "1", "Check MOZ_HEADLESS");
+  Assert.equal(env.get("DISPLAY"), "77", "Check DISPLAY");
+});
+'''
+
+HEADLESS_FALSE = '''
+add_task(function headless_false() {
+  let env = Cc["@mozilla.org/process/environment;1"].getService(
+    Ci.nsIEnvironment
+  );
+  Assert.notEqual(env.get("MOZ_HEADLESS"), "1", "Check MOZ_HEADLESS");
+  Assert.notEqual(env.get("DISPLAY"), "77", "Check DISPLAY");
+});
+'''
+
 
 class XPCShellTestsTests(unittest.TestCase):
     """
@@ -513,7 +533,7 @@ tail =
 
 """ + "\n".join(testlines))
 
-    def assertTestResult(self, expected, shuffle=False, verbose=False):
+    def assertTestResult(self, expected, shuffle=False, verbose=False, headless=False):
         """
         Assert that self.x.runTests with manifest=self.manifest
         returns |expected|.
@@ -525,6 +545,7 @@ tail =
         kwargs['mozInfo'] = mozinfo.info
         kwargs['shuffle'] = shuffle
         kwargs['verbose'] = verbose
+        kwargs['headless'] = headless
         kwargs['sequential'] = True
         kwargs['testingModulesDir'] = os.path.join(objdir, '_tests', 'modules')
         kwargs['utility_path'] = self.utility_path
@@ -1395,6 +1416,38 @@ add_test({
         self.assertInLog(TEST_PASS_STRING)
         self.assertNotInLog(TEST_FAIL_STRING)
 
+    def testNotHeadlessByDefault(self):
+        """
+        Check that the default is not headless.
+        """
+        self.writeFile("test_notHeadlessByDefault.js", HEADLESS_FALSE)
+        self.writeManifest(["test_notHeadlessByDefault.js"])
+        self.assertTestResult(True)
+
+    def testHeadlessWhenHeadlessExplicit(self):
+        """
+        Check that explicitly requesting headless works when the manifest doesn't override.
+        """
+        self.writeFile("test_headlessWhenExplicit.js", HEADLESS_TRUE)
+        self.writeManifest(["test_headlessWhenExplicit.js"])
+        self.assertTestResult(True, headless=True)
+
+    def testHeadlessWhenHeadlessTrueInManifest(self):
+        """
+        Check that enabling headless in the manifest alone works.
+        """
+        self.writeFile("test_headlessWhenTrueInManifest.js", HEADLESS_TRUE)
+        self.writeManifest([("test_headlessWhenTrueInManifest.js", "headless = true")])
+        self.assertTestResult(True)
+
+    def testNotHeadlessWhenHeadlessFalseInManifest(self):
+        """
+        Check that the manifest entry overrides the explicit default.
+        """
+        self.writeFile("test_notHeadlessWhenFalseInManifest.js", HEADLESS_FALSE)
+        self.writeManifest([("test_notHeadlessWhenFalseInManifest.js", "headless = false")])
+        self.assertTestResult(True, headless=True)
+
 
 if __name__ == "__main__":
     mozunit.main()

testing/xpcshell/xpcshellcommandline.py

@@ -144,6 +144,11 @@ def add_common_arguments(parser):
                         action="store_true", default=False,
                         dest="enable_webrender",
                         help="Enable the WebRender compositor in Gecko.")
+    parser.add_argument("--headless",
+                        action="store_true", default=False,
+                        dest="headless",
+                        help="Enable headless mode by default for tests which don't specify "
+                             "whether to use headless mode")
 
 
 def add_remote_arguments(parser):