diff --git a/scripts/construct_context_test.py b/scripts/construct_context_test.py
index 2ff5ac5..34a0e16 100755
--- a/scripts/construct_context_test.py
+++ b/scripts/construct_context_test.py
@@ -24,62 +24,249 @@
 sys.dont_write_bytecode = True
 
 
-def construct_contexts(arglist):
-    args = cc.parse_args(arglist)
-    return cc.construct_contexts(args)
+CONTEXT_JSON = {
+    '28': [
+        {
+            'Name': 'z',
+            'Optional': False,
+            'Host': 'out/zdir/z.jar',
+            'Device': '/system/z.jar',
+            'Subcontexts': [],
+        },
+    ],
+    '29': [
+        {
+            'Name': 'x',
+            'Optional': False,
+            'Host': 'out/xdir/x.jar',
+            'Device': '/system/x.jar',
+            'Subcontexts': [],
+        },
+        {
+            'Name': 'y',
+            'Optional': False,
+            'Host': 'out/ydir/y.jar',
+            'Device': '/product/y.jar',
+            'Subcontexts': [],
+        },
+    ],
+    'any': [
+        {
+            'Name': 'a',
+            'Optional': False,
+            'Host': 'out/adir/a.jar',
+            'Device': '/system/a.jar',
+            'Subcontexts': [
+                {  # Not installed optional, being the only child.
+                    'Name': 'a1',
+                    'Optional': True,
+                    'Host': 'out/a1dir/a1.jar',
+                    'Device': '/product/a1.jar',
+                    'Subcontexts': [],
+                },
+            ],
+        },
+        {
+            'Name': 'b',
+            'Optional': True,
+            'Host': 'out/bdir/b.jar',
+            'Device': '/product/b.jar',
+            'Subcontexts': [
+                {  # Not installed but required.
+                    'Name': 'b1',
+                    'Optional': False,
+                    'Host': 'out/b1dir/b1.jar',
+                    'Device': '/product/b1.jar',
+                    'Subcontexts': [],
+                },
+                {  # Installed optional.
+                    'Name': 'b2',
+                    'Optional': True,
+                    'Host': 'out/b2dir/b2.jar',
+                    'Device': '/product/b2.jar',
+                    'Subcontexts': [],
+                },
+                {  # Not installed optional.
+                    'Name': 'b3',
+                    'Optional': True,
+                    'Host': 'out/b3dir/b3.jar',
+                    'Device': '/product/b3.jar',
+                    'Subcontexts': [],
+                },
+                {  # Installed optional with one more level of nested deps.
+                    'Name': 'b4',
+                    'Optional': True,
+                    'Host': 'out/b4dir/b4.jar',
+                    'Device': '/product/b4.jar',
+                    'Subcontexts': [
+                        {
+                            'Name': 'b41',
+                            'Optional': True,
+                            'Host': 'out/b41dir/b41.jar',
+                            'Device': '/product/b41.jar',
+                            'Subcontexts': [],
+                        },
+                        {
+                            'Name': 'b42',
+                            'Optional': True,
+                            'Host': 'out/b42dir/b42.jar',
+                            'Device': '/product/b42.jar',
+                            'Subcontexts': [],
+                        },
+                    ],
+                },
+            ],
+        },
+        {  # Not installed optional, at the top-level.
+            'Name': 'c',
+            'Optional': True,
+            'Host': 'out/cdir/c.jar',
+            'Device': '/product/c.jar',
+            'Subcontexts': [],
+        },
+    ],
+}
 
 
-contexts = [
-    '--host-context-for-sdk',
-    '28',
-    'PCL[out/zdir/z.jar]',
-    '--target-context-for-sdk',
-    '28',
-    'PCL[/system/z.jar]',
-    '--host-context-for-sdk',
-    '29',
-    'PCL[out/xdir/x.jar]#PCL[out/ydir/y.jar]',
-    '--target-context-for-sdk',
-    '29',
-    'PCL[/system/x.jar]#PCL[/product/y.jar]',
-    '--host-context-for-sdk',
-    'any',
-    'PCL[out/adir/a.jar]#PCL[out/bdir/b.jar]',
-    '--target-context-for-sdk',
-    'any',
-    'PCL[/system/a.jar]#PCL[/product/b.jar]',
-]
+PRODUCT_PACKAGES = ['a', 'b', 'b2', 'b4', 'b41', 'b42', 'x', 'y', 'z']
 
-#pylint: disable=line-too-long
+
+def construct_context_args(target_sdk):
+    return cc.construct_context_args(target_sdk, CONTEXT_JSON, PRODUCT_PACKAGES)
+
+
 class ConstructContextTest(unittest.TestCase):
+    def test_construct_context_27(self):
+        actual = construct_context_args('27')
+        # The order matters.
+        expected = (
+            'class_loader_context_arg='
+            '--class-loader-context=PCL[]{'
+            'PCL[out/xdir/x.jar]#'
+            'PCL[out/ydir/y.jar]#'
+            'PCL[out/zdir/z.jar]#'
+            'PCL[out/adir/a.jar]#'
+            'PCL[out/bdir/b.jar]{'
+            'PCL[out/b1dir/b1.jar]#'
+            'PCL[out/b2dir/b2.jar]#'
+            'PCL[out/b4dir/b4.jar]{'
+            'PCL[out/b41dir/b41.jar]#'
+            'PCL[out/b42dir/b42.jar]'
+            '}'
+            '}'
+            '}'
+            ' ; '
+            'stored_class_loader_context_arg='
+            '--stored-class-loader-context=PCL[]{'
+            'PCL[/system/x.jar]#'
+            'PCL[/product/y.jar]#'
+            'PCL[/system/z.jar]#'
+            'PCL[/system/a.jar]#'
+            'PCL[/product/b.jar]{'
+            'PCL[/product/b1.jar]#'
+            'PCL[/product/b2.jar]#'
+            'PCL[/product/b4.jar]{'
+            'PCL[/product/b41.jar]#'
+            'PCL[/product/b42.jar]'
+            '}'
+            '}'
+            '}')
+        self.assertEqual(actual, expected)
 
     def test_construct_context_28(self):
-        args = ['--target-sdk-version', '28'] + contexts
-        result = construct_contexts(args)
-        expect = (
-            'class_loader_context_arg=--class-loader-context=PCL[]{PCL[out/xdir/x.jar]#PCL[out/ydir/y.jar]#PCL[out/adir/a.jar]#PCL[out/bdir/b.jar]}'
+        actual = construct_context_args('28')
+        expected = (
+            'class_loader_context_arg='
+            '--class-loader-context=PCL[]{'
+            'PCL[out/xdir/x.jar]#'
+            'PCL[out/ydir/y.jar]#'
+            'PCL[out/adir/a.jar]#'
+            'PCL[out/bdir/b.jar]{'
+            'PCL[out/b1dir/b1.jar]#'
+            'PCL[out/b2dir/b2.jar]#'
+            'PCL[out/b4dir/b4.jar]{'
+            'PCL[out/b41dir/b41.jar]#'
+            'PCL[out/b42dir/b42.jar]'
+            '}'
+            '}'
+            '}'
             ' ; '
-            'stored_class_loader_context_arg=--stored-class-loader-context=PCL[]{PCL[/system/x.jar]#PCL[/product/y.jar]#PCL[/system/a.jar]#PCL[/product/b.jar]}')
-        self.assertEqual(result, expect)
+            'stored_class_loader_context_arg='
+            '--stored-class-loader-context=PCL[]{'
+            'PCL[/system/x.jar]#'
+            'PCL[/product/y.jar]#'
+            'PCL[/system/a.jar]#'
+            'PCL[/product/b.jar]{'
+            'PCL[/product/b1.jar]#'
+            'PCL[/product/b2.jar]#'
+            'PCL[/product/b4.jar]{'
+            'PCL[/product/b41.jar]#'
+            'PCL[/product/b42.jar]'
+            '}'
+            '}'
+            '}')
+        self.assertEqual(actual, expected)
 
     def test_construct_context_29(self):
-        args = ['--target-sdk-version', '29'] + contexts
-        result = construct_contexts(args)
-        expect = (
-            'class_loader_context_arg=--class-loader-context=PCL[]{PCL[out/adir/a.jar]#PCL[out/bdir/b.jar]}'
+        actual = construct_context_args('29')
+        expected = (
+            'class_loader_context_arg='
+            '--class-loader-context=PCL[]{'
+            'PCL[out/adir/a.jar]#'
+            'PCL[out/bdir/b.jar]{'
+            'PCL[out/b1dir/b1.jar]#'
+            'PCL[out/b2dir/b2.jar]#'
+            'PCL[out/b4dir/b4.jar]{'
+            'PCL[out/b41dir/b41.jar]#'
+            'PCL[out/b42dir/b42.jar]'
+            '}'
+            '}'
+            '}'
             ' ; '
-            'stored_class_loader_context_arg=--stored-class-loader-context=PCL[]{PCL[/system/a.jar]#PCL[/product/b.jar]}')
-        self.assertEqual(result, expect)
+            'stored_class_loader_context_arg='
+            '--stored-class-loader-context=PCL[]{'
+            'PCL[/system/a.jar]#'
+            'PCL[/product/b.jar]{'
+            'PCL[/product/b1.jar]#'
+            'PCL[/product/b2.jar]#'
+            'PCL[/product/b4.jar]{'
+            'PCL[/product/b41.jar]#'
+            'PCL[/product/b42.jar]'
+            '}'
+            '}'
+            '}')
+        self.assertEqual(actual, expected)
 
     def test_construct_context_S(self):
-        args = ['--target-sdk-version', 'S'] + contexts
-        result = construct_contexts(args)
-        expect = (
-            'class_loader_context_arg=--class-loader-context=PCL[]{PCL[out/adir/a.jar]#PCL[out/bdir/b.jar]}'
+        actual = construct_context_args('S')
+        expected = (
+            'class_loader_context_arg='
+            '--class-loader-context=PCL[]{'
+            'PCL[out/adir/a.jar]#'
+            'PCL[out/bdir/b.jar]{'
+            'PCL[out/b1dir/b1.jar]#'
+            'PCL[out/b2dir/b2.jar]#'
+            'PCL[out/b4dir/b4.jar]{'
+            'PCL[out/b41dir/b41.jar]#'
+            'PCL[out/b42dir/b42.jar]'
+            '}'
+            '}'
+            '}'
             ' ; '
-            'stored_class_loader_context_arg=--stored-class-loader-context=PCL[]{PCL[/system/a.jar]#PCL[/product/b.jar]}')
-        self.assertEqual(result, expect)
-#pylint: enable=line-too-long
+            'stored_class_loader_context_arg='
+            '--stored-class-loader-context=PCL[]{'
+            'PCL[/system/a.jar]#'
+            'PCL[/product/b.jar]{'
+            'PCL[/product/b1.jar]#'
+            'PCL[/product/b2.jar]#'
+            'PCL[/product/b4.jar]{'
+            'PCL[/product/b41.jar]#'
+            'PCL[/product/b42.jar]'
+            '}'
+            '}'
+            '}')
+        self.assertEqual(actual, expected)
+
 
 if __name__ == '__main__':
     unittest.main(verbosity=2)