tests: Add new json-utils tests.

* tests/json-utils.scm ("add-json-fields", "add-json-fields, recursive")
("add-json-fields, recursive, partially preexisting"): New tests.

1 files changed, 26 insertions, 0 deletions

diff --git a/tests/json-utils.scm b/tests/json-utils.scm
index 30f63774345..3e33d182d3a 100644
--- a/tests/json-utils.scm
+++ b/tests/json-utils.scm
@@ -1,5 +1,6 @@
 ;;; GNU Guix --- Functional package management for GNU
 ;;; Copyright © 2026 Nicolas Graves <ngraves@ngraves.fr>
+;;; Copyright © 2026 Maxim Cournoyer <maxim@guixotic.coop>
 ;;;
 ;;; This file is part of GNU Guix.
 ;;;
@@ -161,6 +162,31 @@ captures the written output as a string."
     (equal? (assoc-ref result "name") "my-package")))
 
 ;;;
+;;; add-json-fields
+;;;
+(test-equal "add-json-fields"
+  #("test")
+  (assoc-ref (modify-json*
+                 (add-json-fields '(("exclude" . #("test")))))
+             "exclude"))
+
+(test-equal "add-json-fields, recursive"
+  "^25.9.2"
+  (assoc-ref (assoc-ref (modify-json*
+                            (add-json-fields '(("devDependencies2.@types/node"
+                                                . "^25.9.2"))))
+                        "devDependencies2")
+             "@types/node"))
+
+(test-equal "add-json-fields, recursive, partially preexisting"
+  "^9.9.9"
+  (assoc-ref (assoc-ref (modify-json*
+                            (add-json-fields '(("devDependencies.@types/dummy"
+                                                . "^9.9.9"))))
+                        "devDependencies")
+             "@types/dummy"))
+
+;;;
 ;;; modify-json-fields
 ;;;