add UT + coverage

Author: Michal-Pogorzelec

.gitignore

@@ -55,6 +55,7 @@ dkms.conf
 *.dwo
 
 # Build directories
+build/
 obj/
 bin/
 _codeql_detected_source_root

Makefile

@@ -8,18 +8,22 @@ LDFLAGS =
 SRC_DIR = src
 INC_DIR = include
 EXAMPLES_DIR = examples
-OBJ_DIR = obj
-BIN_DIR = bin
+TEST_DIR = tests
+BUILD_DIR = build
+OBJ_DIR = $(BUILD_DIR)/obj
+BIN_DIR = $(BUILD_DIR)/bin
 
 SRCS = $(wildcard $(SRC_DIR)/*.c)
 OBJS = $(patsubst $(SRC_DIR)/%.c,$(OBJ_DIR)/%.o,$(SRCS))
 
 EXAMPLES = $(wildcard $(EXAMPLES_DIR)/*.c)
 EXAMPLE_BINS = $(patsubst $(EXAMPLES_DIR)/%.c,$(BIN_DIR)/%,$(EXAMPLES))
+TEST_SRC = $(TEST_DIR)/unit_tests.c
+TEST_BIN = $(BIN_DIR)/unit_tests
 
-LIB = libsdlp.a
+LIB = $(BUILD_DIR)/libsdlp.a
 
-.PHONY: all clean examples lib
+.PHONY: all clean examples lib unit-tests test coverage-html
 
 all: lib examples
 
@@ -33,22 +37,30 @@ $(OBJ_DIR)/%.o: $(SRC_DIR)/%.c | $(OBJ_DIR)
 
 examples: $(EXAMPLE_BINS)
 
+unit-tests: $(TEST_BIN)
+
 $(BIN_DIR)/%: $(EXAMPLES_DIR)/%.c $(LIB) | $(BIN_DIR)
 	$(CC) $(CFLAGS) $< $(LIB) -o $@ $(LDFLAGS)
 
-$(OBJ_DIR):
+$(TEST_BIN): $(TEST_SRC) $(LIB) | $(BIN_DIR)
+	$(CC) $(CFLAGS) $< $(LIB) -o $@ $(LDFLAGS)
+
+$(BUILD_DIR):
+	mkdir -p $(BUILD_DIR)
+
+$(OBJ_DIR): | $(BUILD_DIR)
 	mkdir -p $(OBJ_DIR)
 
-$(BIN_DIR):
+
+$(BIN_DIR): | $(BUILD_DIR)
 	mkdir -p $(BIN_DIR)
 
 clean:
-	rm -rf $(OBJ_DIR) $(BIN_DIR) $(LIB)
-
-.PHONY: test
-test: examples
-	@echo "Running TM example..."
-	@./$(BIN_DIR)/tm_example
-	@echo ""
-	@echo "Running TC example..."
-	@./$(BIN_DIR)/tc_example
+	rm -rf $(BUILD_DIR) obj bin libsdlp.a
+
+coverage-html:
+	bash scripts/coverage_html.sh
+
+test: unit-tests
+	@echo "Running unit tests..."
+	@./$(TEST_BIN)

README.md

@@ -56,15 +56,15 @@ make all
 ```
 
 This will create:
-- `libsdlp.a` - Static library
-- `bin/tm_example` - TM frame example
-- `bin/tc_example` - TC frame example
+- `build/libsdlp.a` - Static library
+- `build/bin/tm_example` - TM frame example
+- `build/bin/tc_example` - TC frame example
 
 ### Build Library Only
 
 ```bash
 make lib
-# Produces: libsdlp.a (static)
+# Produces: build/libsdlp.a (static)
 ```
 
 ### Build Examples
@@ -79,6 +79,26 @@ make examples
 make test
 ```
 
+### Coverage (HTML)
+
+Requires `gcovr` installed in your system:
+
+```bash
+sudo apt install gcovr
+```
+
+Generate coverage report:
+
+```bash
+make coverage-html
+```
+
+Output report:
+
+```text
+build/coverage/index.html
+```
+
 ### Clean
 
 ```bash

include/sdlp_tc.h

@@ -38,7 +38,7 @@ typedef struct {
     uint16_t control_command_flag : 1;
     uint16_t reserved : 2;
     uint16_t spacecraft_id : 10;
-    uint8_t virtual_channel_id : 6;
+    uint16_t virtual_channel_id : 6;
     uint16_t frame_length : 10;
     uint8_t frame_sequence_number;
 } sdlp_tc_header_t;

scripts/coverage_html.sh

@@ -0,0 +1,32 @@
+#!/usr/bin/env bash
+set -euo pipefail
+
+ROOT_DIR="$(cd "$(dirname "${BASH_SOURCE[0]}")/.." && pwd)"
+OUT_FILE="${1:-${ROOT_DIR}/build/coverage/index.html}"
+
+if [[ "${OUT_FILE}" != /* ]]; then
+  OUT_FILE="${ROOT_DIR}/${OUT_FILE}"
+fi
+
+COVERAGE_CFLAGS='-O0 -g --coverage -Iinclude -Wall -Wextra -Wpedantic -Wconversion -Wshadow -Wcast-align -Wcast-qual -Wpointer-arith -Wformat=2 -Wmissing-prototypes -Wstrict-prototypes -Wredundant-decls -Wundef -std=c11'
+
+cd "${ROOT_DIR}"
+
+if ! command -v gcovr >/dev/null 2>&1; then
+  echo "Error: gcovr is not installed."
+  echo "Install with: pip install gcovr"
+  exit 1
+fi
+
+make clean >/dev/null
+make unit-tests CFLAGS="${COVERAGE_CFLAGS}" >/dev/null
+./build/bin/unit_tests >/dev/null
+
+mkdir -p "$(dirname "${OUT_FILE}")"
+gcovr -r "${ROOT_DIR}" \
+  --filter "${ROOT_DIR}/src" \
+  --html \
+  --html-details \
+  --output "${OUT_FILE}"
+
+echo "Coverage HTML report written to: ${OUT_FILE}"

src/sdlp_tc.c

@@ -52,9 +52,10 @@ int sdlp_tc_encode_frame(const sdlp_tc_frame_t *frame, uint8_t *buffer,
                        ((frame->header.reserved & 0x03u) << 2) |
                        ((frame->header.spacecraft_id >> 8) & 0x03u));
     buffer[offset++] = (uint8_t)(frame->header.spacecraft_id & 0xffu);
-    buffer[offset++] = (uint8_t)(((frame->header.virtual_channel_id & 0x3fu) << 2) | 0x00u);
-    buffer[offset++] = (uint8_t)((frame->header.frame_length >> 8) & 0xffu);
+    buffer[offset++] = (uint8_t)(((frame->header.virtual_channel_id & 0x3fu) << 2) |
+                       ((frame->header.frame_length >> 8) & 0x03u));
     buffer[offset++] = (uint8_t)(frame->header.frame_length & 0xffu);
+    buffer[offset++] = frame->header.frame_sequence_number;
 
 #ifdef TC_SEGMENT_HEADER_ENABLED
     if (!frame->header.control_command_flag) {
@@ -93,10 +94,10 @@ int sdlp_tc_decode_frame(const uint8_t *buffer, size_t buffer_size,
     offset += 2;
 
     frame->header.virtual_channel_id = (uint8_t)((buffer[offset] >> 2) & 0x3fu);
-    offset++;
-    
-    frame->header.frame_length = (uint16_t)(((uint16_t)buffer[offset] << 8) | buffer[offset + 1]);
+    frame->header.frame_length = (uint16_t)((((uint16_t)buffer[offset] & 0x03u) << 8) |
+                                 (uint16_t)buffer[offset + 1]);
     offset += 2;
+    frame->header.frame_sequence_number = buffer[offset++];
 
 #ifdef TC_SEGMENT_HEADER_ENABLED
     if (!frame->header.control_command_flag) {

tests/cunit.h

@@ -0,0 +1,50 @@
+/* Tiny C unit test helpers. Suitable for embedding in small projects.
+ * Usage: include this header in a single C test file and implement test
+ * functions returning 0 on success, non-zero on failure. Use RUN_TEST(fn).
+ */
+#ifndef CUNIT_H
+#define CUNIT_H
+
+#include <stdio.h>
+#include <string.h>
+
+static int cunit_overall_failures = 0;
+
+#define ASSERT_EQ_INT(expected, actual)                                        \
+  do {                                                                         \
+    if ((int)(expected) != (int)(actual)) {                                    \
+      printf("ASSERT_EQ_INT failed: %s:%d: expected %d got %d\n", __FILE__,    \
+             __LINE__, (int)(expected), (int)(actual));                        \
+      return 1;                                                                \
+    }                                                                          \
+  } while (0)
+
+#define ASSERT_EQ_MEM(a, b, len)                                               \
+  do {                                                                         \
+    if (memcmp((a), (b), (len)) != 0) {                                        \
+      printf("ASSERT_EQ_MEM failed: %s:%d\n", __FILE__, __LINE__);             \
+      return 1;                                                                \
+    }                                                                          \
+  } while (0)
+
+#define ASSERT_TRUE(cond)                                                      \
+  do {                                                                         \
+    if (!(cond)) {                                                             \
+      printf("ASSERT_TRUE failed: %s:%d\n", __FILE__, __LINE__);               \
+      return 1;                                                                \
+    }                                                                          \
+  } while (0)
+
+#define RUN_TEST(fn)                                                           \
+  do {                                                                         \
+    printf("RUN %s\n", #fn);                                                   \
+    int r = fn();                                                              \
+    if (r == 0)                                                                \
+      printf("PASS %s\n", #fn);                                                \
+    else {                                                                     \
+      printf("FAIL %s\n", #fn);                                                \
+      cunit_overall_failures++;                                                \
+    }                                                                          \
+  } while (0)
+
+#endif /* CUNIT_H */