During test, log to in-memory log

v0/test.c

@@ -2,9 +2,11 @@
 #include <setjmp.h>
 #include <stdio.h>
 #include <string.h>
+#include <stdlib.h>
 
 static jmp_buf s_testJmp;
 static const char* s_failMsg;
+static char* s_logOutput = NULL;
 
 void fail(const char* msg) {
     s_failMsg = msg;
@@ -23,6 +25,27 @@ void assert_str(const char* expected, const char* actual, const char* msg) {
     }
 }
 
+static void log_append(const char* msg) {
+    size_t oldLen = s_logOutput ? strlen(s_logOutput) : 0;
+    size_t newLen = oldLen + strlen(msg) + 1;
+    char* newOutput = malloc(newLen);
+    if (newOutput) {
+        if (s_logOutput) {
+            strcpy(newOutput, s_logOutput);
+            free(s_logOutput);
+        } else {
+            newOutput[0] = '\0';
+        }
+        strcat(newOutput, msg);
+        s_logOutput = newOutput;
+    }
+}
+
+static void log_clear() {
+    free(s_logOutput);
+    s_logOutput = NULL;
+}
+
 typedef struct {
     const char* name;
     Test func;
@@ -59,11 +82,14 @@ int main(int argc, char** argv) {
     const char* failedTests[s_totalTests + 1];
     int failedCount = 0;
 
+    log_set_output(log_append);
+
     for (int i = 0; i < s_totalTests; i++) {
         printf("%s...", s_tests[i].name);
         s_failMsg = NULL;
 
         if (setjmp(s_testJmp) == 0) {
+            log_clear();
             s_tests[i].func();
             printf(" [OK]\n");
             s_greenTests++;