diff --git a/src/libfetchers-tests/input.cc b/src/libfetchers-tests/input.cc
new file mode 100644
index 000000000..faff55f2c
--- /dev/null
+++ b/src/libfetchers-tests/input.cc
@@ -0,0 +1,61 @@
+#include "nix/fetchers/fetch-settings.hh"
+#include "nix/fetchers/attrs.hh"
+#include "nix/fetchers/fetchers.hh"
+
+#include <gtest/gtest.h>
+
+#include <string>
+
+namespace nix {
+
+using fetchers::Attr;
+
+struct InputFromAttrsTestCase
+{
+    fetchers::Attrs attrs;
+    std::string expectedUrl;
+    std::string description;
+    fetchers::Attrs expectedAttrs = attrs;
+};
+
+class InputFromAttrsTest : public ::testing::WithParamInterface<InputFromAttrsTestCase>, public ::testing::Test
+{};
+
+TEST_P(InputFromAttrsTest, attrsAreCorrectAndRoundTrips)
+{
+    fetchers::Settings fetchSettings;
+
+    const auto & testCase = GetParam();
+
+    auto input = fetchers::Input::fromAttrs(fetchSettings, fetchers::Attrs(testCase.attrs));
+
+    EXPECT_EQ(input.toAttrs(), testCase.expectedAttrs);
+    EXPECT_EQ(input.toURLString(), testCase.expectedUrl);
+
+    auto input2 = fetchers::Input::fromAttrs(fetchSettings, input.toAttrs());
+    EXPECT_EQ(input, input2);
+    EXPECT_EQ(input.toAttrs(), input2.toAttrs());
+}
+
+INSTANTIATE_TEST_SUITE_P(
+    InputFromAttrs,
+    InputFromAttrsTest,
+    ::testing::Values(
+        // Test for issue #14429.
+        InputFromAttrsTestCase{
+            .attrs =
+                {
+                    {"url", Attr("git+ssh://git@github.com/NixOS/nixpkgs")},
+                    {"type", Attr("git")},
+                },
+            .expectedUrl = "git+ssh://git@github.com/NixOS/nixpkgs",
+            .description = "strips_git_plus_prefix",
+            .expectedAttrs =
+                {
+                    {"url", Attr("ssh://git@github.com/NixOS/nixpkgs")},
+                    {"type", Attr("git")},
+                },
+        }),
+    [](const ::testing::TestParamInfo<InputFromAttrsTestCase> & info) { return info.param.description; });
+
+} // namespace nix
diff --git a/src/libfetchers-tests/meson.build b/src/libfetchers-tests/meson.build
index a18f64d79..6bccdb05c 100644
--- a/src/libfetchers-tests/meson.build
+++ b/src/libfetchers-tests/meson.build
@@ -42,6 +42,7 @@ sources = files(
   'access-tokens.cc',
   'git-utils.cc',
   'git.cc',
+  'input.cc',
   'nix_api_fetchers.cc',
   'public-key.cc',
 )