support/testing: new patch runtime test

Signed-off-by: Julien Olivain <ju.o@free.fr>
Signed-off-by: Thomas Petazzoni <thomas.petazzoni@bootlin.com>

DEVELOPERS

@@ -1962,6 +1962,8 @@ F:	support/testing/tests/package/test_ola.py
 F:	support/testing/tests/package/test_ola/
 F:	support/testing/tests/package/test_openblas.py
 F:	support/testing/tests/package/test_parted.py
+F:	support/testing/tests/package/test_patch.py
+F:	support/testing/tests/package/test_patch/
 F:	support/testing/tests/package/test_pciutils.py
 F:	support/testing/tests/package/test_perftest.py
 F:	support/testing/tests/package/test_pigz.py

support/testing/tests/package/test_patch.py

@@ -0,0 +1,44 @@
+import os
+
+import infra.basetest
+
+
+class TestPatch(infra.basetest.BRTest):
+    rootfs_overlay = \
+        infra.filepath("tests/package/test_patch/rootfs-overlay")
+    config = infra.basetest.BASIC_TOOLCHAIN_CONFIG + \
+        f"""
+        BR2_PACKAGE_BUSYBOX_SHOW_OTHERS=y
+        BR2_PACKAGE_PATCH=y
+        BR2_ROOTFS_OVERLAY="{rootfs_overlay}"
+        BR2_TARGET_ROOTFS_CPIO=y
+        # BR2_TARGET_ROOTFS_TAR is not set
+        """
+
+    def test_run(self):
+        cpio_file = os.path.join(self.builddir, "images", "rootfs.cpio")
+        self.emulator.boot(arch="armv5",
+                           kernel="builtin",
+                           options=["-initrd", cpio_file])
+        self.emulator.login()
+
+        # Check the program can execute. This also checks that we are
+        # not using the patch applet from BusyBox (as it does not
+        # recognize the --version option).
+        self.assertRunOk("patch --version")
+
+        # We check the test file contains our expected string before
+        # the patch.
+        sed_cmd = "sed -n '2p' file.txt"
+        out, ret = self.emulator.run(sed_cmd)
+        self.assertEqual(ret, 0)
+        self.assertEqual(out[0], "Hello World!")
+
+        # We apply our test patch...
+        self.assertRunOk("patch -p1 < file.diff")
+
+        # We check the test file contains our expected string after
+        # applying the patch.
+        out, ret = self.emulator.run(sed_cmd)
+        self.assertEqual(ret, 0)
+        self.assertEqual(out[0], "Hello Buildroot!")

support/testing/tests/package/test_patch/rootfs-overlay/root/file.diff

@@ -0,0 +1,8 @@
+diff -Naur a/file.txt b/file.txt
+--- a/file.txt	2024-12-18 23:11:50.863359248 +0100
++++ b/file.txt	2024-12-18 23:12:26.464561146 +0100
+@@ -1,3 +1,3 @@
+ This is some context...
+-Hello World!
++Hello Buildroot!
+ ...and this is some more context.

support/testing/tests/package/test_patch/rootfs-overlay/root/file.txt

@@ -0,0 +1,3 @@
+This is some context...
+Hello World!
+...and this is some more context.