diff --git a/src/strops.c b/strops.c
similarity index 86%
rename from src/strops.c
rename to strops.c
index 4d126e7..77525ce 100644
--- a/src/strops.c
+++ b/strops.c
@@ -37,7 +37,27 @@ char* strops_to_uppercase(const char* string) {
     return result;
 }
 
-char* strops_insert_at_pos(const char* string, const char* string_to_insert, size_t pos) {
+int strops_is_lowercase(const char* string) {
+    size_t i;
+    for (i = 0; i < strlen(string); i++) {
+        if (!(string[i] >= 'a' && string[i] <= 'z')) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+int strops_is_uppercase(const char* string) {
+    size_t i;
+    for (i = 0; i < strlen(string); i++) {
+        if (!(string[i] >= 'A' && string[i] <= 'Z')) {
+            return 0;
+        }
+    }
+    return 1;
+}
+
+char* strops_insert_at_pos_string(const char* string, const char* string_to_insert, size_t pos) {
     assert(pos <= strlen(string) && "pos needs to be inside string");
     size_t string_length = strlen(string) + strlen(string_to_insert) + 1;
     char *result = malloc(string_length);
@@ -54,7 +74,7 @@ char* strops_insert_at_pos(const char* string, const char* string_to_insert, siz
     return result;
 }
 
-char* strops_remove_at_pos(const char* string, size_t pos) {
+char* strops_remove_at_pos_char(const char* string, size_t pos) {
     assert(pos <= strlen(string) && "pos needs to be inside string");
     char *result = malloc(strlen(string));
     memcpy(result, string, strlen(string));
@@ -71,7 +91,7 @@ char* strops_trim_right_whitespace(const char* string) {
     char *result = malloc(strlen(string) + 1);
     memcpy(result, string, strlen(string));
     while (strchr("\t\n\v\f\r ", result[strlen(result) - 1]) != NULL) {
-        result = strops_remove_at_pos(result, strlen(result) - 1);
+        result = strops_remove_at_pos_char(result, strlen(result) - 1);
     }
     result = realloc(result, strlen(result));
     return result;
@@ -81,7 +101,7 @@ char* strops_trim_left_whitespace(const char* string) {
     char *result = malloc(strlen(string) + 1);
     memcpy(result, string, strlen(string));
     while (strchr("\t\n\v\f\r ", result[0]) != NULL) {
-        result = strops_remove_at_pos(result, 0);
+        result = strops_remove_at_pos_char(result, 0);
     }
     result = realloc(result, strlen(result));
     return result;
@@ -99,7 +119,7 @@ char* strops_trim_right_chars(const char* string, const char* chars_to_remove) {
     char *result = malloc(strlen(string) + 1);
     memcpy(result, string, strlen(string));
     while (strchr(chars_to_remove, result[strlen(result) - 1]) != NULL) {
-        result = strops_remove_at_pos(result, strlen(result) - 1);
+        result = strops_remove_at_pos_char(result, strlen(result) - 1);
     }
     result = realloc(result, strlen(result));
     return result;
@@ -109,7 +129,7 @@ char* strops_trim_left_chars(const char* string, const char* chars_to_remove) {
     char *result = malloc(strlen(string) + 1);
     memcpy(result, string, strlen(string));
     while (strchr(chars_to_remove, result[0]) != NULL) {
-        result = strops_remove_at_pos(result, 0);
+        result = strops_remove_at_pos_char(result, 0);
     }
     result = realloc(result, strlen(result));
     return result;
@@ -133,7 +153,7 @@ char* strops_trim_right_string(const char* string, const char* string_to_remove)
     while (strcmp(tmp, string_to_remove) == 0) {
         size_t i;
         for (i = 0; i < strlen(string_to_remove); i++) {
-            result  = strops_remove_at_pos(result, offset);
+            result  = strops_remove_at_pos_char(result, offset);
         }
         offset = strlen(result) - strlen(string_to_remove);
         tmp = result + offset;
@@ -152,7 +172,7 @@ char* strops_trim_left_string(const char* string, const char* string_to_remove)
     while (strcmp(tmp, string_to_remove) == 0) {
         size_t i;
         for (i = 0; i < strlen(string_to_remove); i++) {
-            result  = strops_remove_at_pos(result, 0);
+            result  = strops_remove_at_pos_char(result, 0);
         }
         memcpy(tmp, result, strlen(string_to_remove));
     }
@@ -177,7 +197,7 @@ char* strops_remove_chars(const char* string, const char* chars_to_remove) {
     size_t i;
     for (i = 0; i < strlen(chars_to_remove); i++) {
         while (strchr(result, chars_to_remove[i]) != NULL) {
-            result = strops_remove_at_pos(result, strlen(result) - strlen(strchr(result, chars_to_remove[i])));
+            result = strops_remove_at_pos_char(result, strlen(result) - strlen(strchr(result, chars_to_remove[i])));
         }
     }
     result = realloc(result, strlen(result));
@@ -193,7 +213,7 @@ char* strops_remove_string(const char* string, const char* string_to_remove) {
         size_t offset = strlen(result) - strlen(strstr(result, string_to_remove));
         size_t i;
         for (i = 0; i < strlen(string_to_remove); i++) {
-            result  = strops_remove_at_pos(result, offset);
+            result  = strops_remove_at_pos_char(result, offset);
         }
     }
     result = realloc(result, strlen(result));
@@ -242,6 +262,10 @@ size_t strops_word_count(const char* string) {
     return word_count;
 }
 
+int strops_is_url_encoded(const char* string) {
+    return -1;
+}
+
 char* strops_url_encode(const char* string) {
     /* multiplied by 3, because example: ( => %28. Three times the chars */
     char *result = malloc(strlen(string) * 3 + 1);
diff --git a/src/strops.h b/strops.h
similarity index 83%
rename from src/strops.h
rename to strops.h
index 089d6a6..6ea535e 100644
--- a/src/strops.h
+++ b/strops.h
@@ -12,9 +12,11 @@
 
 char* strops_to_lowercase(const char* string);
 char* strops_to_uppercase(const char* string);
+int strops_is_lowercase(const char* string);
+int strops_is_uppercase(const char* string);
 
-char* strops_insert_at_pos(const char* string, const char* string_to_insert, size_t pos);
-char* strops_remove_at_pos(const char* string, size_t pos);
+char* strops_insert_at_pos_string(const char* string, const char* string_to_insert, size_t pos);
+char* strops_remove_at_pos_char(const char* string, size_t pos);
 
 char* strops_trim_right_whitespace(const char* string);
 char* strops_trim_left_whitespace(const char* string);
@@ -34,6 +36,7 @@ char* strops_remove_string(const char* string, const char* string_to_remove);
 size_t strops_word_count(const char* string);
 
 /* https://www.w3schools.com/tags/ref_urlencode.asp */
+int strops_is_url_encoded(const char* string);
 char* strops_url_encode(const char* string);
 char* strops_url_decode(const char* string);
 
diff --git a/src/tests.c b/tests.c
similarity index 62%
rename from src/tests.c
rename to tests.c
index a388f66..b899be6 100644
--- a/src/tests.c
+++ b/tests.c
@@ -1,5 +1,26 @@
 #include "strops.h"
 #include <stdio.h>
+#include <stdlib.h>
+
+/* https://gist.githubusercontent.com/rexim/b5b0c38f53157037923e7cdd77ce685d/raw/86c3db57f485f3b6f7958f308ba7126fa81282d8/da_append.c */
+#define da_append(xs, x)                                                             \
+    do {                                                                             \
+        if ((xs)->count >= (xs)->capacity) {                                         \
+            if ((xs)->capacity == 0) (xs)->capacity = 256;                           \
+            else (xs)->capacity *= 2;                                                \
+            (xs)->items = realloc((xs)->items, (xs)->capacity*sizeof(*(xs)->items)); \
+        }                                                                            \
+                                                                                     \
+        (xs)->items[(xs)->count++] = (x);                                            \
+    } while (0)
+
+typedef int(*fnptr)();
+typedef struct {
+    fnptr* items;
+    size_t capacity;
+    size_t count;
+    size_t amount_successful;
+} Tests;
 
 /* Test template (Maybe make a macro in the future?)
 int test_() {
@@ -39,24 +60,48 @@ int test_to_uppercase() {
     return 0;
 }
 
-int test_insert_at_pos() {
+int test_is_lowercase() {
+    char* input = "string";
+    int expected = 1;
+    int result = strops_is_lowercase(input);
+    if (result != expected) {
+        printf("test_is_lowercase failed\n");
+        printf("Got = %d\nExpected = %d\n", result, expected);
+        return 1;
+    }
+    return 0;
+}
+
+int test_is_uppercase() {
+    char* input = "sTrInG";
+    int expected = 0;
+    int result = strops_is_uppercase(input);
+    if (result != expected) {
+        printf("test_is_uppercase failed\n");
+        printf("Got = %d\nExpected = %d\n", result, expected);
+        return 1;
+    }
+    return 0;
+}
+
+int test_insert_at_pos_string() {
     char* input = "Heo, World!";
     char* expected = "Hello, World!";
-    char* result = strops_insert_at_pos(input, "ll", 2);
+    char* result = strops_insert_at_pos_string(input, "ll", 2);
     if (strcmp(result, expected) != 0) {
-        printf("test_insert_at_pos failed\n");
+        printf("test_insert_at_pos_string failed\n");
         printf("Got = '%s'\nExpected = '%s'\n", result, expected);
         return 1;
     }
     return 0;
 }
 
-int test_remove_at_pos() {
+int test_remove_at_pos_char() {
     char* input = "Hello";
     char* expected = "Hllo";
-    char* result = strops_remove_at_pos(input, 1);
+    char* result = strops_remove_at_pos_char(input, 1);
     if (strcmp(result, expected) != 0) {
-        printf("test_remove_at_pos failed\n");
+        printf("test_remove_at_pos_char failed\n");
         printf("Got = '%s'\nExpected = '%s'\n", result, expected);
         return 1;
     }
@@ -207,6 +252,33 @@ int test_word_count() {
     return 0;
 }
 
+int test_is_url_encoded() {
+    int ret = 0;
+    char* input;
+    int expected;
+    int result;
+
+    input = "(artist)";
+    expected = 0;
+    result = strops_is_url_encoded(input);
+    if (result != expected) {
+        printf("test_is_url_encoded failed\n");
+        printf("Got = %d\nExpected = %d\n", result, expected);
+        ret = 1;
+    }
+
+    input = "%28artist%29";
+    expected = 1;
+    result = strops_is_url_encoded(input);
+    if (result != expected) {
+        printf("test_is_url_encoded failed\n");
+        printf("Got = %d\nExpected = %d\n", result, expected);
+        ret = 1;
+    }
+
+    return ret;
+}
+
 int test_url_encode() {
     char* input = "(artist)";
     char* expected = "%28artist%29";
@@ -232,112 +304,43 @@ int test_url_decode() {
 }
 
 int main() {
-    int amount_of_tests = 18;
-    int amount_of_successful_tests = 0;
-    int ret;
-    
-    /* Test template
-        ret = test_();
-        if (ret == 0) {
-            amount_of_successful_tests++;
+    Tests tests = { 0 };
+    da_append(&tests, test_to_lowercase);
+    da_append(&tests, test_to_lowercase);
+    da_append(&tests, test_to_uppercase);
+    da_append(&tests, test_is_lowercase);
+    da_append(&tests, test_is_uppercase);
+    da_append(&tests, test_insert_at_pos_string);
+    da_append(&tests, test_remove_at_pos_char);
+    da_append(&tests, test_trim_right_whitespace);
+    da_append(&tests, test_trim_left_whitespace);
+    da_append(&tests, test_trim_both_whitespace);
+    da_append(&tests, test_trim_right_chars);
+    da_append(&tests, test_trim_left_chars);
+    da_append(&tests, test_trim_both_chars);
+    da_append(&tests, test_trim_right_string);
+    da_append(&tests, test_trim_left_string);
+    da_append(&tests, test_trim_both_string);
+    da_append(&tests, test_remove_chars);
+    da_append(&tests, test_remove_string);
+    da_append(&tests, test_word_count);
+    da_append(&tests, test_is_url_encoded);
+    da_append(&tests, test_url_encode);
+    da_append(&tests, test_url_decode);
+        
+    size_t i;
+    for (i = 0; i < tests.count; i++) {
+        if (tests.items[i]() == 0) {
+            tests.amount_successful++;
         }
-    */
-
-    ret = test_to_lowercase();
-    if (ret == 0) {
-        amount_of_successful_tests++;
     }
 
-    ret = test_to_uppercase();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_insert_at_pos();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_remove_at_pos();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_trim_right_whitespace();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_trim_left_whitespace();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_trim_both_whitespace();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_trim_right_chars();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_trim_left_chars();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_trim_both_chars();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_trim_right_string();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_trim_left_string();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_trim_both_string();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_remove_chars();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_remove_string();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_word_count();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_url_encode();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    ret = test_url_decode();
-    if (ret == 0) {
-        amount_of_successful_tests++;
-    }
-
-    if (amount_of_successful_tests != amount_of_tests) {
-        printf("%d/%d tests passed successfully\n", amount_of_successful_tests, amount_of_tests);
+   if (tests.amount_successful != tests.count) {
+        printf("%d/%d tests passed successfully\n", tests.amount_successful, tests.count);
         return 1;
     } else {
         printf("All tests passed successfully\n");
         return 0;
     }
 }
+