fopen and tests

tests/c/argv.c

@@ -1,9 +1,10 @@
 #include <stdio.h>
+#include <assert.h>
 
-int main(int argc, char *argv[]) {
+int main(int argc, char *argv[])
+{
   char *self = argv[0];
   char first = self[0];
-  if (first != '/') {
-    return 1;
-  }
+
+  assert((first < 128) && "argv[0] is not ascii/utf-8");
 }

tests/c/fopen.c

@@ -0,0 +1,16 @@
+#include <stdio.h>
+#include <errno.h>
+#include <assert.h>
+
+int main(int argc, char *argv[]) {
+    FILE *file1 = fopen("./c/fopen.c", "r");
+    assert(file1 && "failed to open file");
+    
+    FILE *file2 = fopen("./c/fopen.c", "meow");
+    assert(!file2 && "succeeded opening file despite invalid argument");
+    assert((errno == EINVAL) && "wrong errno");
+
+    FILE *file3 = fopen("/this-does-absolutely-not-exist-at-all-edhjkefhew98", "r");
+    assert(!file3 && "succeeded despite file not existing");
+    assert((errno == ENOENT) && "wrong errno");
+}

tests/c/getenv.c

@@ -1,14 +1,12 @@
 #include <stdlib.h>
+#include <assert.h>
 
-int main(int argc, char *argv[]) {
+int main(int argc, char *argv[])
+{
   char *env = getenv("PATH");
-  if (!env) {
-    return 1;
-  }
+  assert(env && "PATH doesnt exist");
 
   char *env2 = getenv(
       "__some absolutely NONSENSE that no one would ever define please..");
-  if (env2) {
-    return 1;
-  }
+  assert(!env2 && "nonsense environment variable found");
 }

tests/c/malloc.c

@@ -1,7 +1,10 @@
 #include <stdlib.h>
+#include <assert.h>
 
-int main(void) {
+int main(void)
+{
   char *alloc = (char *)malloc(10);
+  assert(alloc && "allocation failed");
   *alloc = 1;
   *(alloc + 9) = 2;
   free(alloc);

tests/c/mem.c

@@ -1,13 +1,14 @@
 #include <string.h>
+#include <assert.h>
 
-int main(void) {
+int main(void)
+{
   char buf[10];
 
   memset(buf, 34, sizeof(buf));
 
-  for (int i = 0; i < 10; ++i) {
-    if (buf[i] != 34) {
-      return 1;
-    }
+  for (int i = 0; i < 10; ++i)
+  {
+    assert((buf[i] == 34) && "memset failed to write byte");
   }
 }

tests/c/simple_printf.c

@@ -1,8 +1,8 @@
 #include <stdio.h>
+#include <assert.h>
 
-int main(int argc, char *argv[]) {
+int main(int argc, char *argv[])
+{
   int result = printf("Hello, world!\n");
-  if (result != 14) {
-    return 1;
-  }
+  assert((result == 14) && "printf returned wrong number of chars");
 }

tests/c/strtol.c

@@ -1,9 +1,9 @@
 #include <stdlib.h>
+#include <assert.h>
 
-int main(void) {
+int main(void)
+{
   char *str = "12";
   long value = strtol(str, NULL, 10);
-  if (value != 12) {
-    return 1;
-  }
+  assert((value == 12) && "value must be 12");
 }