updater: Add "write_value()" function.
write_value(value, filename) writes 'value' to 'filename'. It can be
used to tune device settings when applying an OTA package. For example,
write_value("960000", "/sys/devices/system/cpu/cpu0/cpufreq/scaling_max_freq").
Bug: 32463933
Test: recovery_component_test passes.
Test: Apply an OTA package that contains a call to write_value(), and
check the result.
Change-Id: Ib009ecb8a45a94353f10c59e2383fe1f49796e35
diff --git a/tests/component/updater_test.cpp b/tests/component/updater_test.cpp
index a029cf4..d34c0e5 100644
--- a/tests/component/updater_test.cpp
+++ b/tests/component/updater_test.cpp
@@ -322,3 +322,36 @@
CloseArchive(handle);
}
+
+TEST_F(UpdaterTest, write_value) {
+ // write_value() expects two arguments.
+ expect(nullptr, "write_value()", kArgsParsingFailure);
+ expect(nullptr, "write_value(\"arg1\")", kArgsParsingFailure);
+ expect(nullptr, "write_value(\"arg1\", \"arg2\", \"arg3\")", kArgsParsingFailure);
+
+ // filename cannot be empty.
+ expect(nullptr, "write_value(\"value\", \"\")", kArgsParsingFailure);
+
+ // Write some value to file.
+ TemporaryFile temp_file;
+ std::string value = "magicvalue";
+ std::string script("write_value(\"" + value + "\", \"" + std::string(temp_file.path) + "\")");
+ expect("t", script.c_str(), kNoCause);
+
+ // Verify the content.
+ std::string content;
+ ASSERT_TRUE(android::base::ReadFileToString(temp_file.path, &content));
+ ASSERT_EQ(value, content);
+
+ // Allow writing empty string.
+ script = "write_value(\"\", \"" + std::string(temp_file.path) + "\")";
+ expect("t", script.c_str(), kNoCause);
+
+ // Verify the content.
+ ASSERT_TRUE(android::base::ReadFileToString(temp_file.path, &content));
+ ASSERT_EQ("", content);
+
+ // It should fail gracefully when write fails.
+ script = "write_value(\"value\", \"/proc/0/file1\")";
+ expect("", script.c_str(), kNoCause);
+}