feat: Add dummy game utility and enhance testing capabilities

- also improve argument handling

Makefile

@@ -17,11 +17,13 @@ ALL_LIBS := $(LIBS) $(SDL_LIBS) $(FFMPEG_LIBS) -lm
 
 BUILD_DIR ?= build
 TARGET = $(BUILD_DIR)/gsplash
+DUMMY_TARGET = $(BUILD_DIR)/dummy_game
 SRC = src/gsplash.c
+DUMMY_SRC = src/dummy_game.c
 
 .PHONY: all clean install uninstall check
 
-all: $(TARGET)
+all: $(TARGET) $(DUMMY_TARGET)
 
 $(BUILD_DIR):
 	mkdir -p $(BUILD_DIR)
@@ -29,11 +31,16 @@ $(BUILD_DIR):
 $(TARGET): $(BUILD_DIR) $(SRC)
 	$(CC) $(ALL_CFLAGS) $(LDFLAGS) $(SRC) -o $@ $(ALL_LIBS)
 
+$(DUMMY_TARGET): $(BUILD_DIR) $(DUMMY_SRC)
+	$(CC) $(CFLAGS) $(SDL_CFLAGS) $(LDFLAGS) $(DUMMY_SRC) -o $@ $(SDL_LIBS)
+
 # Lightweight smoke test (headless via SDL_VIDEODRIVER=dummy)
-check: $(TARGET)
+check: $(TARGET) $(DUMMY_TARGET)
 	@echo "Running smoke test (headless)..."
 	SDL_VIDEODRIVER=dummy $(TARGET) nonexistent.png /bin/true || true
-	@echo "Smoke test finished"
+	@echo "Running CLI test suite..."
+	./tests/test_cli.sh
+	@echo "All tests finished successfully"
 
 install: $(TARGET)
 	install -d "$(DESTDIR)$(bindir)"
@@ -43,4 +50,4 @@ uninstall:
 	rm -f "$(DESTDIR)$(bindir)/gsplash"
 
 clean:
-	rm -f $(TARGET)
+	rm -f $(TARGET) $(DUMMY_TARGET)

README.md

@@ -39,14 +39,38 @@ sudo make install
 DESTDIR=/some/staging/path make install
 ```
 
-## Smoke test (headless)
+## Testing
 
-Run a lightweight headless smoke test that uses the dummy video driver so it doesn't require a display:
+Gsplash includes several testing utilities to ensure proper functionality without requiring a heavy game binary.
+
+### Automated Testing
+
+Run the automated test suite (which includes a headless smoke test and CLI argument validation) using:
 
 ```bash
 make check
 ```
 
+### Interactive Visual Testing
+
+To physically test the splash screen rendering modes (`stretch`, `center`, `crop`) with a real image, use the interactive test script. It launches `gsplash` with each mode and prompts you to confirm if it displayed correctly:
+
+```bash
+./tests/test_interactive.sh path/to/your/image.png
+```
+*(Tip: You can place your test images in the `tests/assets/` directory).*
+
+### Dummy Game Utility
+
+For manual testing, a `dummy_game` binary is built alongside `gsplash`. It mimics a real game by sleeping to simulate startup time, creating an SDL window to trigger `gsplash`'s focus loss detection and exiting cleanly.
+
+```bash
+./build/gsplash path/to/image.png ./build/dummy_game
+
+# Test with a custom 10 second simulated game load time
+./build/gsplash path/to/image.png ./build/dummy_game 10
+```
+
 ## Usage
 
 ```bash

src/dummy_game.c

@@ -0,0 +1,67 @@
+#include <SDL2/SDL.h>
+#include <stdio.h>
+#include <stdlib.h>
+#include <unistd.h>
+
+int main(int argc, char *argv[]) {
+    int delay_seconds = 5;
+    if (argc > 1) {
+        int parsed = atoi(argv[1]);
+        if (parsed > 0) {
+            delay_seconds = parsed;
+        }
+    }
+
+    printf("[dummy_game] Simulating engine startup for %d seconds...\n", delay_seconds);
+    for (int i = 0; i < delay_seconds; i++) {
+        sleep(1);
+        printf("[dummy_game] Loading... %d/%d\n", i + 1, delay_seconds);
+    }
+
+    printf("[dummy_game] Creating window to trigger focus-loss on splash screen...\n");
+    if (SDL_Init(SDL_INIT_VIDEO) < 0) {
+        fprintf(stderr, "[dummy_game] SDL Init Failed: %s\n", SDL_GetError());
+        return 1;
+    }
+
+    SDL_Window *window = SDL_CreateWindow(
+        "Dummy Game Window",
+        SDL_WINDOWPOS_CENTERED, SDL_WINDOWPOS_CENTERED,
+        800, 600,
+        SDL_WINDOW_SHOWN | SDL_WINDOW_RESIZABLE
+    );
+
+    if (!window) {
+        fprintf(stderr, "[dummy_game] Window Creation Failed: %s\n", SDL_GetError());
+        SDL_Quit();
+        return 1;
+    }
+
+    SDL_Renderer *renderer = SDL_CreateRenderer(window, -1, SDL_RENDERER_ACCELERATED);
+    if (renderer) {
+        SDL_SetRenderDrawColor(renderer, 0, 120, 255, 255);
+        SDL_RenderClear(renderer);
+        SDL_RenderPresent(renderer);
+    }
+
+    printf("[dummy_game] Window created. Waiting 5 seconds before exiting...\n");
+
+    SDL_Event event;
+    int running = 1;
+    Uint32 start_time = SDL_GetTicks();
+    
+    while (running && (SDL_GetTicks() - start_time < 5000)) {
+        while (SDL_PollEvent(&event)) {
+            if (event.type == SDL_QUIT) {
+                running = 0;
+            }
+        }
+        SDL_Delay(50);
+    }
+
+    printf("[dummy_game] Exiting normally.\n");
+    if (renderer) SDL_DestroyRenderer(renderer);
+    SDL_DestroyWindow(window);
+    SDL_Quit();
+    return 0;
+}

src/gsplash.c

@@ -317,8 +317,14 @@ int main(int argc, char *argv[])
         render_mode = parse_render_mode(argv[1] + 7);
         arg_index += 1;
     }
-    else if (argc >= 4 && strcmp(argv[1], "-m") == 0)
+    else if (argc >= 2 && strcmp(argv[1], "-m") == 0)
     {
+        if (argc < 4)
+        {
+            log_error("Usage: %s [--mode=stretch|center|crop] <image_path> <game_executable> [args...]", argv[0]);
+            log_error("       %s -m stretch|center|crop <image_path> <game_executable> [args...]", argv[0]);
+            return 1;
+        }
         render_mode = parse_render_mode(argv[2]);
         arg_index += 2;
     }
@@ -333,7 +339,7 @@ int main(int argc, char *argv[])
     const char *image_path = argv[arg_index];
     const char *game_path = argv[arg_index + 1];
 
-    log_info("Starting splash: image='%s', game='%s'", image_path, game_path);
+    log_info("Starting splash: image='%s', game='%s', mode=%d", image_path, game_path, render_mode);
 
     // Initialize SDL2 Video subsystems
     if (SDL_Init(SDL_INIT_VIDEO) < 0)

tests/test_cli.sh

@@ -0,0 +1,83 @@
+#!/bin/bash
+
+# A test suite for testing CLI argument permutations of gsplash
+
+GSPLASH="./build/gsplash"
+GAME="/bin/true"
+IMAGE="nonexistent.png" 
+
+if [ ! -f "$GSPLASH" ]; then
+    echo "Please run 'make' first to build gsplash."
+    exit 1
+fi
+
+export SDL_VIDEODRIVER=dummy
+
+pass=0
+fail=0
+
+run_test() {
+    local expected_status=$1
+    shift
+    local expected_log="$1"
+    shift
+    local desc="$1"
+    shift
+    
+    printf "Test: %-45s " "$desc"
+    
+    # Run the command and capture output
+    local output
+    output=$($GSPLASH "$@" 2>&1)
+    local status=$?
+    
+    local passed=true
+    local error_msg=""
+
+    if [ $status -ne $expected_status ]; then
+        passed=false
+        error_msg="Expected status $expected_status, got $status"
+    elif [ -n "$expected_log" ]; then
+        if ! echo "$output" | grep -q "$expected_log"; then
+            passed=false
+            error_msg="Expected log missing: $expected_log"
+        fi
+    fi
+
+    if $passed; then
+        echo "PASS"
+        pass=$((pass+1))
+    else
+        echo "FAIL ($error_msg)"
+        fail=$((fail+1))
+    fi
+}
+
+echo "=== Running CLI Argument Tests ==="
+
+# Valid combinations (0=STRETCH, 1=CENTER, 2=CROP)
+run_test 0 "mode=1" "Basic invocation" $IMAGE $GAME
+run_test 0 "mode=0" "Long mode: stretch" --mode=stretch $IMAGE $GAME
+run_test 0 "mode=1" "Long mode: center" --mode=center $IMAGE $GAME
+run_test 0 "mode=2" "Long mode: crop" --mode=crop $IMAGE $GAME
+run_test 0 "mode=0" "Long mode: fallback to stretch" --mode=invalid $IMAGE $GAME
+run_test 0 "mode=0" "Short mode: stretch" -m stretch $IMAGE $GAME
+run_test 0 "mode=1" "Short mode: center" -m center $IMAGE $GAME
+run_test 0 "mode=2" "Short mode: crop" -m crop $IMAGE $GAME
+run_test 0 "mode=0" "Short mode: fallback to stretch" -m whatever $IMAGE $GAME
+run_test 0 "mode=1" "With game arguments" $IMAGE $GAME arg1 arg2
+run_test 0 "mode=2" "Mode and game arguments" -m crop $IMAGE $GAME arg1 arg2
+
+# Invalid combinations (Usage errors, so we just check for status 1, no specific log needed)
+run_test 1 "" "No arguments"
+run_test 1 "" "Only image" $IMAGE
+run_test 1 "" "Missing arg for short mode (-m only)" -m $IMAGE
+run_test 1 "" "Missing game for short mode" -m stretch $IMAGE
+
+echo "================================================="
+echo "Tests completed: $pass passed, $fail failed."
+
+if [ $fail -gt 0 ]; then
+    exit 1
+fi
+exit 0

tests/test_interactive.sh

@@ -0,0 +1,69 @@
+#!/bin/bash
+
+GSPLASH="./build/gsplash"
+DUMMY="./build/dummy_game"
+
+if [ ! -f "$GSPLASH" ] || [ ! -f "$DUMMY" ]; then
+    echo "Please run 'make' first to build gsplash and dummy_game."
+    exit 1
+fi
+
+if [ -z "$1" ]; then
+    echo "Usage: $0 <path_to_test_image_or_video>"
+    exit 1
+fi
+
+IMAGE="$1"
+if [ ! -f "$IMAGE" ]; then
+    echo "Error: File '$IMAGE' not found."
+    exit 1
+fi
+
+echo "=== Interactive gsplash Visual Test ==="
+echo "This will physically display the splash screen using different modes."
+echo "You will be asked to confirm if it looked correct after each test."
+echo ""
+
+pass=0
+fail=0
+
+run_interactive_test() {
+    local mode="$1"
+    
+    echo "------------------------------------------------"
+    echo "Testing mode: $mode"
+    echo "Launching in 2 seconds (it will stay open for 3 seconds)..."
+    sleep 2
+    
+    # Run gsplash with a 3-second dummy game
+    $GSPLASH --mode="$mode" "$IMAGE" "$DUMMY" 3
+    
+    # Prompt the user interactively
+    while true; do
+        read -p "Did it display correctly for mode '$mode'? [y/N] " response
+        case "$response" in
+            [yY][eE][sS]|[yY])
+                echo "=> PASS recorded."
+                pass=$((pass+1))
+                break
+                ;;
+            [nN][oO]|[nN]|"")
+                echo "=> FAIL recorded."
+                fail=$((fail+1))
+                break
+                ;;
+            *)
+                echo "Please answer y or n."
+                ;;
+        esac
+    done
+}
+
+run_interactive_test "stretch"
+run_interactive_test "center"
+run_interactive_test "crop"
+
+echo "================================================"
+echo "Interactive Testing Complete!"
+echo "Passed: $pass"
+echo "Failed: $fail"