From 944f6d5425c0e8dbb85e82f810b313434ae703a2 Mon Sep 17 00:00:00 2001
From: Federico Angelilli <code@fedang.net>
Date: Wed, 15 Jan 2025 20:49:07 +0100
Subject: Implement string escape for any_json

---
 any_json.h  | 59 ++++++++++++++++++++++++++++++++++++++++++++++++++++++++---
 test/json.c | 10 +++++-----
 test/log.c  |  2 +-
 3 files changed, 62 insertions(+), 9 deletions(-)

diff --git a/any_json.h b/any_json.h
index 021a997..e7e4419 100644
--- a/any_json.h
+++ b/any_json.h
@@ -39,6 +39,7 @@ bool any_json_write_null(any_json_write_t *json);
 #ifdef ANY_JSON_IMPLEMENT
 
 #include <string.h>
+#include <ctype.h>
 
 #ifndef ANY_JSON_INDENT
 #define ANY_JSON_INDENT 4
@@ -108,17 +109,69 @@ bool any_json_write_member(any_json_write_t *json, const char *key)
     }
 }
 
+#ifndef ANY_JSON_BUFFER_SIZE
+#define ANY_JSON_BUFFER_SIZE 512
+#endif
+
 bool any_json_write_string(any_json_write_t *json, const char *string)
 {
     json->fputs("\"", json->stream);
-    json->fputs(string, json->stream);
+
+    char buffer[ANY_JSON_BUFFER_SIZE] = { 0 };
+    size_t t = 0;
+
+    for (size_t i = 0; string[i] != '\0'; ++i) {
+        if (t + 6 >= sizeof(buffer)) {
+            buffer[t] = '\0';
+            json->fputs(buffer, json->stream);
+            t = 0;
+        }
+
+        if (iscntrl(string[i])) {
+            buffer[t++] = '\\';
+
+            switch (string[i]) {
+                case '\b':
+                    buffer[t++] = 'b';
+                    break;
+                case '\f':
+                    buffer[t++] = 'f';
+                    break;
+                case '\n':
+                    buffer[t++] = 'n';
+                    break;
+                case '\r':
+                    buffer[t++] = 'r';
+                    break;
+                case '\t':
+                    buffer[t++] = 't';
+                    break;
+                default:
+                    t += sprintf(buffer + t, "u%04x", string[i]);
+                    break;
+            }
+        } else {
+            if (string[i] == '"' || string[i] == '\\' || string[i] == '/')
+                buffer[t++] = '\\';
+
+            buffer[t++] = string[i];
+        }
+    }
+
+    buffer[t] = '\0';
+    json->fputs(buffer, json->stream);
+
     json->fputs("\"", json->stream);
 }
 
+#ifndef ANY_JSON_NUMBER_FORMAT
+#define ANY_JSON_NUMBER_FORMAT "%.17g"
+#endif
+
 bool any_json_write_number(any_json_write_t *json, double value)
 {
-    char buffer[1080] = { 0 };
-    snprintf(buffer, sizeof(buffer), "%lf", value);
+    char buffer[ANY_JSON_BUFFER_SIZE] = { 0 };
+    snprintf(buffer, sizeof(buffer), ANY_JSON_NUMBER_FORMAT, value);
     json->fputs(buffer, json->stream);
 }
 
diff --git a/test/json.c b/test/json.c
index 635f474..e491c44 100644
--- a/test/json.c
+++ b/test/json.c
@@ -55,9 +55,9 @@ void test_write(bool pretty)
 
     const char *props[][2] = {
         { "name", "test" },
-        { "scope", "local" },
-        { "project", "any_json" },
-        { "author", "me" },
+        { "scope", "local \x1f" },
+        { "project", "any_json とてもクールで縮みません" },
+        { "author", "me \"trying\" hard" },
         { 0 },
     };
 
@@ -82,10 +82,10 @@ void test_write(bool pretty)
         any_json_write_open_array(&json);
         {
             any_json_write_member(&json, NULL);
-            any_json_write_string(&json, "nested");
+            any_json_write_string(&json, "nested \\ \" /");
 
             any_json_write_member(&json, NULL);
-            any_json_write_string(&json, "array");
+            any_json_write_string(&json, "array \f \b \n \r \t o");
         }
         any_json_write_close_array(&json);
     }
diff --git a/test/log.c b/test/log.c
index c3e0dd5..7f7d889 100644
--- a/test/log.c
+++ b/test/log.c
@@ -1,6 +1,6 @@
 #include <stdbool.h>
 
-#define ANY_LOG_LOCKING
+//#define ANY_LOG_LOCKING
 #define ANY_LOG_IMPLEMENT
 #define ANY_LOG_MODULE "test"
 
-- 
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