repo: Check that GI module override function is callable

Previously, we would return the override function if it was null, or a
non-callable object, and then try to call it. Add tests for this case.

10 files changed, 75 insertions, 2 deletions

diff --git a/gi/repo.cpp b/gi/repo.cpp
index 27e78b5e..92d67d65 100644
--- a/gi/repo.cpp
+++ b/gi/repo.cpp
@@ -556,9 +556,12 @@ lookup_override_function(JSContext             *cx,
         goto fail;
     }
 
+    // If the override module is present, it must have a callable _init(). An
+    // override module without _init() is probably unintentional. (function
+    // being undefined means there was no override module.)
     if (!gjs_object_require_property(cx, module, "override module",
                                      atoms.init(), function) ||
-        !function.isObjectOrNull()) {
+        !function.isObject() || !JS::IsCallable(&function.toObject())) {
         gjs_throw(cx, "Unexpected value for _init in overrides module");
         goto fail;
     }
diff --git a/installed-tests/js/jsunit.gresources.xml b/installed-tests/js/jsunit.gresources.xml
index 209274fc..75c54c90 100644
--- a/installed-tests/js/jsunit.gresources.xml
+++ b/installed-tests/js/jsunit.gresources.xml
@@ -13,6 +13,10 @@
     <file>modules/badOverrides/Gio.js</file>
     <file>modules/badOverrides/Regress.js</file>
     <file>modules/badOverrides/WarnLib.js</file>
+    <file>modules/badOverrides2/GIMarshallingTests.js</file>
+    <file>modules/badOverrides2/Gio.js</file>
+    <file>modules/badOverrides2/Regress.js</file>
+    <file>modules/badOverrides2/WarnLib.js</file>
     <file>modules/subBadInit/__init__.js</file>
     <file>modules/subErrorInit/__init__.js</file>
     <file>modules/data.txt</file>
diff --git a/installed-tests/js/meson.build b/installed-tests/js/meson.build
index 5520a19d..6db887d2 100644
--- a/installed-tests/js/meson.build
+++ b/installed-tests/js/meson.build
@@ -127,6 +127,7 @@ jasmine_tests = [
     'GObjectValue',
     'GTypeClass',
     'Importer',
+    'Importer2',
     'Introspection',
     'Lang',
     'LegacyByteArray',
diff --git a/installed-tests/js/modules/badOverrides2/.eslintrc.yml b/installed-tests/js/modules/badOverrides2/.eslintrc.yml
new file mode 100644
index 00000000..b1c10f5d
--- /dev/null
+++ b/installed-tests/js/modules/badOverrides2/.eslintrc.yml
@@ -0,0 +1,8 @@
+---
+# SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
+# SPDX-FileCopyrightText: 2018 Philip Chimento <philip.chimento@gmail.com>
+rules:
+  no-throw-literal: 'off'  # these are intended to be bad code
+  no-unused-vars:
+    - error
+    - varsIgnorePattern: ^_init$
diff --git a/installed-tests/js/modules/badOverrides2/GIMarshallingTests.js b/installed-tests/js/modules/badOverrides2/GIMarshallingTests.js
new file mode 100644
index 00000000..6cf2dfa9
--- /dev/null
+++ b/installed-tests/js/modules/badOverrides2/GIMarshallingTests.js
@@ -0,0 +1,5 @@
+// Sabotage the import of imports.gi.GIMarshallingTests!
+// SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 Philip Chimento <philip.chimento@gmail.com>
+
+var _init = {thingsThatThisObjectIsNot: ['callable']};
diff --git a/installed-tests/js/modules/badOverrides2/Gio.js b/installed-tests/js/modules/badOverrides2/Gio.js
new file mode 100644
index 00000000..9758a7c0
--- /dev/null
+++ b/installed-tests/js/modules/badOverrides2/Gio.js
@@ -0,0 +1,5 @@
+// Sabotage the import of imports.gi.Gio!
+// SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 Philip Chimento <philip.chimento@gmail.com>
+
+var _init = null;
diff --git a/installed-tests/js/modules/badOverrides2/Regress.js b/installed-tests/js/modules/badOverrides2/Regress.js
new file mode 100644
index 00000000..e4252f67
--- /dev/null
+++ b/installed-tests/js/modules/badOverrides2/Regress.js
@@ -0,0 +1,5 @@
+// Sabotage the import of imports.gi.Regress!
+// SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 Philip Chimento <philip.chimento@gmail.com>
+
+var _init;
diff --git a/installed-tests/js/modules/badOverrides2/WarnLib.js b/installed-tests/js/modules/badOverrides2/WarnLib.js
new file mode 100644
index 00000000..b2c93b05
--- /dev/null
+++ b/installed-tests/js/modules/badOverrides2/WarnLib.js
@@ -0,0 +1,3 @@
+// Sabotage the import of imports.gi.WarnLib!
+// SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 Philip Chimento <philip.chimento@gmail.com>
diff --git a/installed-tests/js/testImporter.js b/installed-tests/js/testImporter.js
index 8380af20..f03bf634 100644
--- a/installed-tests/js/testImporter.js
+++ b/installed-tests/js/testImporter.js
@@ -32,7 +32,7 @@ describe('GI importer', function () {
             expect(() => imports.gi.Regress).toThrow('💩');
         });
 
-        it("throws an exception when the overrides _init isn't a function", function () {
+        it('throws an exception when the overrides _init is a primitive', function () {
             expect(() => imports.gi.Gio).toThrowError(/_init/);
         });
     });
diff --git a/installed-tests/js/testImporter2.js b/installed-tests/js/testImporter2.js
new file mode 100644
index 00000000..b4e71225
--- /dev/null
+++ b/installed-tests/js/testImporter2.js
@@ -0,0 +1,39 @@
+// SPDX-License-Identifier: MIT OR LGPL-2.0-or-later
+// SPDX-FileCopyrightText: 2023 Philip Chimento <philip.chimento@gmail.com>
+
+// This test is in a separate file instead of testImporter.js, because it tests
+// loading overrides for g-i modules, and in the original file we have literally
+// run out of g-i modules to override -- at least, the ones that we can assume
+// will be present on any system where GJS is compiled.
+
+describe('GI importer', function () {
+    describe('on failure', function () {
+        // For these tests, we provide special overrides files to sabotage the
+        // import, at the path resource:///org/gjs/jsunit/modules/badOverrides2.
+        let oldSearchPath;
+        beforeAll(function () {
+            oldSearchPath = imports.overrides.searchPath.slice();
+            imports.overrides.searchPath = ['resource:///org/gjs/jsunit/modules/badOverrides2'];
+        });
+
+        afterAll(function () {
+            imports.overrides.searchPath = oldSearchPath;
+        });
+
+        it("throws an exception when the overrides _init isn't a function", function () {
+            expect(() => imports.gi.GIMarshallingTests).toThrowError(/_init/);
+        });
+
+        it('throws an exception when the overrides _init is null', function () {
+            expect(() => imports.gi.Gio).toThrowError(/_init/);
+        });
+
+        it('throws an exception when the overrides _init is undefined', function () {
+            expect(() => imports.gi.Regress).toThrowError(/_init/);
+        });
+
+        it('throws an exception when the overrides _init is missing', function () {
+            expect(() => imports.gi.WarnLib).toThrowError(/_init/);
+        });
+    });
+});