✨ (file): Add clear

Delete file content but file still exists

include/interface/platform/File.h

@@ -32,6 +32,7 @@ struct File {
 
 	virtual void seek(size_t pos, int origin) = 0;
 
+	virtual void clear()  = 0;
 	virtual void rewind() = 0;
 
 	virtual auto size() -> std::size_t = 0;

libs/FileManagerKit/include/FileManagerKit.h

@@ -35,7 +35,10 @@ struct File : public interface::File, public mbed::NonCopyable<File> {
 	auto write(const char *data, uint32_t size) -> std::size_t final;
 
 	void seek(size_t pos, int origin = SEEK_SET) final;
+
+	void clear() final;
 	void rewind() final;
+
 	auto size() -> std::size_t final;
 
 	auto tell() -> std::size_t final;

libs/FileManagerKit/source/File.cpp

@@ -100,6 +100,11 @@ void File::seek(size_t pos, int origin)
 	std::fseek(_file.get(), static_cast<long>(pos), origin);
 }
 
+void File::clear()
+{
+	reopen(_path, "w+");
+}
+
 void File::rewind()
 {
 	seek(0);

libs/FileManagerKit/tests/File_test.cpp

@@ -864,3 +864,30 @@ TEST_F(FileTest, clearError)
 
 	ASSERT_FALSE(error_after_clear);
 }
+
+TEST_F(FileTest, clear)
+{
+	auto input_data = std::to_array<uint8_t>({0x61, 0x62, 0x63, 0x64, 0x65, 0x66});	  // "abcdef"
+
+	writeTempFile(input_data);
+
+	file.open(tempFilename);
+	auto size = file.size();
+	EXPECT_NE(size, 0);
+
+	file.clear();
+
+	size = file.size();
+	EXPECT_EQ(size, 0);
+
+	file.close();
+}
+
+TEST_F(FileTest, clearNotExistingFile)
+{
+	ASSERT_FALSE(file.is_open());
+
+	file.clear();
+
+	// nothing expected
+}

tests/unit/mocks/mocks/leka/File.h

@@ -35,6 +35,7 @@ class File : public interface::File
 
 	MOCK_METHOD(void, seek, (size_t, int), (override));
 
+	MOCK_METHOD(void, clear, (), (override));
 	MOCK_METHOD(void, rewind, (), (override));
 
 	MOCK_METHOD(size_t, size, (), (override));