aconfig: add rust integration test for aconfig_storage_write_api

Bug: b/312444587
Test: atest aconfig_storage_write_api.test.rust
Change-Id: I05f992ea93a19507ad865e97315c128473841a33
diff --git a/tools/aconfig/TEST_MAPPING b/tools/aconfig/TEST_MAPPING
index 4acbe60..2f1694b 100644
--- a/tools/aconfig/TEST_MAPPING
+++ b/tools/aconfig/TEST_MAPPING
@@ -78,6 +78,10 @@
       "name": "aconfig_storage_read_api.test"
     },
     {
+      // aconfig_storage write api rust integration tests
+      "name": "aconfig_storage_write_api.test.rust"
+    },
+    {
       // aconfig_storage read api rust integration tests
       "name": "aconfig_storage_read_api.test.rust"
     },
diff --git a/tools/aconfig/aconfig_storage_write_api/tests/Android.bp b/tools/aconfig/aconfig_storage_write_api/tests/Android.bp
new file mode 100644
index 0000000..bb8c6df
--- /dev/null
+++ b/tools/aconfig/aconfig_storage_write_api/tests/Android.bp
@@ -0,0 +1,19 @@
+
+rust_test {
+    name: "aconfig_storage_write_api.test.rust",
+    srcs: [
+        "storage_write_api_test.rs"
+    ],
+    rustlibs: [
+        "libanyhow",
+        "libaconfig_storage_file",
+        "libaconfig_storage_read_api",
+        "libaconfig_storage_write_api",
+        "libprotobuf",
+        "libtempfile",
+    ],
+    data: [
+        "flag.val",
+    ],
+    test_suites: ["general-tests"],
+}
diff --git a/tools/aconfig/aconfig_storage_write_api/tests/storage_write_api_test.rs b/tools/aconfig/aconfig_storage_write_api/tests/storage_write_api_test.rs
new file mode 100644
index 0000000..f6c1bbc
--- /dev/null
+++ b/tools/aconfig/aconfig_storage_write_api/tests/storage_write_api_test.rs
@@ -0,0 +1,73 @@
+#[cfg(not(feature = "cargo"))]
+mod aconfig_storage_write_api_test {
+    use aconfig_storage_file::protos::ProtoStorageFiles;
+    use aconfig_storage_read_api::flag_value_query::find_boolean_flag_value;
+    use aconfig_storage_write_api::{mapped_file::get_mapped_file, set_boolean_flag_value};
+
+    use protobuf::Message;
+    use std::fs::{self, File};
+    use std::io::{Read, Write};
+    use tempfile::NamedTempFile;
+
+    /// Write storage location record pb to a temp file
+    fn write_storage_record_file(flag_val: &str) -> NamedTempFile {
+        let text_proto = format!(
+            r#"
+files {{
+    version: 0
+    container: "system"
+    package_map: "some_package_map"
+    flag_map: "some_flag_map"
+    flag_val: "{}"
+    timestamp: 12345
+}}
+"#,
+            flag_val
+        );
+        let storage_files: ProtoStorageFiles =
+            protobuf::text_format::parse_from_str(&text_proto).unwrap();
+        let mut binary_proto_bytes = Vec::new();
+        storage_files.write_to_vec(&mut binary_proto_bytes).unwrap();
+        let mut file = NamedTempFile::new().unwrap();
+        file.write_all(&binary_proto_bytes).unwrap();
+        file
+    }
+
+    /// Create temp file copy
+    fn copy_to_temp_rw_file(source_file: &str) -> NamedTempFile {
+        let file = NamedTempFile::new().unwrap();
+        fs::copy(source_file, file.path()).unwrap();
+        file
+    }
+
+    /// Get boolean flag value from offset
+    fn get_boolean_flag_value_at_offset(file: &str, offset: u32) -> bool {
+        let mut f = File::open(file).unwrap();
+        let mut bytes = Vec::new();
+        f.read_to_end(&mut bytes).unwrap();
+        find_boolean_flag_value(&bytes, offset).unwrap()
+    }
+
+    #[test]
+    /// Test to lock down flag value update api
+    fn test_boolean_flag_value_update() {
+        let flag_value_file = copy_to_temp_rw_file("./flag.val");
+        let flag_value_path = flag_value_file.path().display().to_string();
+        let record_pb_file = write_storage_record_file(&flag_value_path);
+        let record_pb_path = record_pb_file.path().display().to_string();
+
+        // SAFETY:
+        // The safety here is ensured as only this single threaded test process will
+        // write to this file
+        let mut file = unsafe { get_mapped_file(&record_pb_path, "system").unwrap() };
+        for i in 0..8 {
+            set_boolean_flag_value(&mut file, i, true).unwrap();
+            let value = get_boolean_flag_value_at_offset(&flag_value_path, i);
+            assert!(value);
+
+            set_boolean_flag_value(&mut file, i, false).unwrap();
+            let value = get_boolean_flag_value_at_offset(&flag_value_path, i);
+            assert!(!value);
+        }
+    }
+}