test: add structure & framework for writing tests

Makefile

@@ -2,12 +2,18 @@ LIB_FILENAME ?= libvieter.a
 
 BUILD_DIR ?= build
 SRC_DIR ?= src
+TEST_DIR ?= test
 INC_DIRS ?= include
 
 SRCS != find '$(SRC_DIR)' -iname '*.c'
 SRCS_H != find $(INC_DIRS) -iname '*.h'
+SRCS_TEST != find '$(TEST_DIR)' -iname '*.c'
+
 OBJS := $(SRCS:%=$(BUILD_DIR)/%.o)
-DEPS := $(SRCS:%=$(BUILD_DIR)/%.d)
+OBJS_TEST := $(SRCS_TEST:%=$(BUILD_DIR)/%.o)
+DEPS := $(SRCS:%=$(BUILD_DIR)/%.d) $(SRCS_TEST:%=$(BUILD_DIR)/%.d)
+
+BINS_TEST := $(OBJS_TEST:%.c.o=%)
 
 INC_FLAGS := $(addprefix -I,$(INC_DIRS))
 
@@ -16,7 +22,7 @@ INC_FLAGS := $(addprefix -I,$(INC_DIRS))
 #  object file is also recompiled if only a header is changed.
 # -MP: generate a dummy target for every header file (according to the  docs it
 #  prevents some errors when removing header files)
-CFLAGS ?= $(INC_FLAGS) -O3 -MMD -MP -Wall -Werror -Wextra
+CFLAGS ?= $(INC_FLAGS) -MMD -MP -Wall -Werror -Wextra
 
 .PHONY: all
 all: vieter
@@ -28,19 +34,37 @@ vieter: $(BUILD_DIR)/$(LIB_FILENAME)
 $(BUILD_DIR)/$(LIB_FILENAME): $(OBJS)
 	ar -rcs $@ $(OBJS)
 
-$(BUILD_DIR)/%.c.o: %.c
+$(BUILD_DIR)/$(SRC_DIR)/%.c.o: $(SRC_DIR)/%.c
 	mkdir -p $(dir $@)
 	$(CC) $(CFLAGS) -c $< -o $@
 
 
+# =====TESTING=====
+.PHONY: test
+test: build-test
+	@ $(foreach bin,$(BINS_TEST),./$(bin);)
+
+.PHONY: build-test
+build-test: $(BINS_TEST)
+
+# For simplicity, we link every object file to each of the test files. This
+# might be changed later if this starts to become too slow.
+$(BINS_TEST): %: %.c.o $(OBJS)
+	$(CC) $^ -o $@
+
+# Each test includes the test directory, which contains the acutest header file
+$(BUILD_DIR)/$(TEST_DIR)/%.c.o: $(TEST_DIR)/%.c
+	mkdir -p $(dir $@)
+	$(CC) $(CFLAGS) -I$(TEST_DIR) -c $< -o $@
+
 # =====MAINTENANCE=====
 .PHONY: lint
 lint:
-	clang-format -n --Werror $(SRCS) $(SRCS_H)
+	clang-format -n --Werror $(SRCS) $(SRCS_H) $(SRCS_TEST)
 
 .PHONY: fmt
 fmt:
-	clang-format -i $(SRCS) $(SRCS_H)
+	clang-format -i $(SRCS) $(SRCS_H) $(SRCS_TEST)
 
 .PHONY: clean
 clean:

README.md

@@ -13,6 +13,21 @@ Currently it contains the following:
 
 ## Development
 
+### Compilation
+
+Everything is handled by the provided Makefile. To compile the static library,
+simply run `make`.
+
+### Testing
+
+This library uses [Acutest](https://github.com/mity/acutest) for its tests.
+Tests should be placed in the `test` subdirectory, further divided into
+directories that correspond those in `src`. Test files should begin with
+`test_`, and their format should follow the expected format for Acutest.
+
+To run the tests, simply run `make test`. If you wish to only run a specific
+test binary, you can find them in `build/test`.
+
 ### `compile_commands.json`
 
 Clangd requires a `compile_commands.json` to function properly. You can
@@ -21,6 +36,7 @@ generate it using [bear](https://github.com/rizsotto/Bear):
 ```sh
 make clean
 bear -- make
+bear --append -- make build-test
 ```
 
 This will create a `compile_commands.json` file in the current directory.

test/cron/test_parse.c

@@ -0,0 +1,69 @@
+#include "acutest.h"
+#include "vieter_cron.h"
+
+void test_tutorial(void) {
+  void *mem;
+
+  mem = malloc(10);
+  TEST_CHECK(mem != NULL);
+
+  mem = realloc(mem, 20);
+  TEST_CHECK(mem != NULL);
+
+  free(mem);
+}
+
+void test_fail(void) {
+  int a, b;
+
+  /* This condition is designed to fail so you can see what the failed test
+   * output looks like. */
+  a = 1;
+  b = 2;
+  TEST_CHECK(a + b == 5);
+
+  /* Here is TEST_CHECK_ in action. */
+  TEST_CHECK_(a + b == 5, "%d + %d == 5", a, b);
+
+  /* We may also show more information about the failure. */
+  if (!TEST_CHECK(a + b == 5)) {
+    TEST_MSG("a: %d", a);
+    TEST_MSG("b: %d", b);
+  }
+
+  /* The macro TEST_MSG() only outputs something when the preceding
+   * condition fails, so we can avoid the 'if' statement. */
+  TEST_CHECK(a + b == 3);
+  TEST_MSG("a: %d", a);
+  TEST_MSG("b: %d", b);
+}
+
+static void helper(void) {
+  /* Kill the current test with a condition which is never true. */
+  TEST_ASSERT(1 == 2);
+
+  /* This never happens because the test is aborted above. */
+  TEST_CHECK(1 + 2 == 2 + 1);
+}
+
+void test_abort(void) {
+  helper();
+
+  /* This test never happens because the test is aborted inside the helper()
+   * function. */
+  TEST_CHECK(1 * 2 == 2 * 1);
+}
+
+void test_crash(void) {
+  int *invalid = ((int *)NULL) + 0xdeadbeef;
+
+  *invalid = 42;
+  TEST_CHECK_(1 == 1, "This should never execute, due to a write into "
+                      "an invalid address.");
+}
+
+TEST_LIST = {{"tutorial", test_tutorial},
+             {"fail", test_fail},
+             {"abort", test_abort},
+             {"crash", test_crash},
+             {NULL, NULL}};