src/testing.c: Fix show_colour() logic; add it to tests

2 files changed, 9 insertions, 4 deletions

diff --git a/src/testing.c b/src/testing.c
index aa58bc7..e2c087c 100644
--- a/src/testing.c
+++ b/src/testing.c
@@ -18,7 +18,7 @@ ENVVAR_NAME = "NO_COLOR";
 static bool
 show_colour(void) {
 	const char *const no_colour = getenv(ENVVAR_NAME);
-	return (no_colour != NULL) && (no_colour[0] != '\0');
+	return (no_colour == NULL) || (no_colour[0] == '\0');
 }
 
 void
diff --git a/tests/testing.c b/tests/testing.c
index eeb0a39..3c605a7 100644
--- a/tests/testing.c
+++ b/tests/testing.c
@@ -1,18 +1,21 @@
 #include "../src/testing.c"
 
+#include <assert.h>
+
 
 int
 main(void) {
-	int rc = -1;
+	int rc = 1;
 
 	test_start("testing.c");
-	const int should_overwrite = 1;
+	const bool should_overwrite = true;
 
 	if (unsetenv(ENVVAR_NAME)) {
 		perror("unsetenv(\"NO_COLOR\")");
 		goto out;
 	}
 	{
+		assert(show_colour() == true);
 		testing("unset NO_COLOR");
 		test_ok();
 	}
@@ -22,6 +25,7 @@ main(void) {
 		goto out;
 	}
 	{
+		assert(show_colour() == true);
 		testing("empty NO_COLOR");
 		test_ok();
 	}
@@ -31,11 +35,12 @@ main(void) {
 		goto out;
 	}
 	{
+		assert(show_colour() == false);
 		testing("defined NO_COLOR");
 		test_ok();
 	}
 
 	rc = 0;
 out:
-	return !!rc;
+	return rc;
 }