fix blob; throw on non stone reads; update blob test

scripts/engine.cm

@@ -333,6 +333,8 @@ var $_ = create_actor()
 $_.random = crypto.random
 $_.random[cell.DOC] = "returns a number between 0 and 1. There is a 50% chance that the result is less than 0.5."
 
+$_.random_fit = crypto.random_fit
+
 $_.clock = function(fn) { return os.now() }
 $_.clock[cell.DOC] = "takes a function input value that will eventually be called with the current time in number form."
 

source/blob.h

@@ -197,10 +197,12 @@ void copy_bits_fast(const void *src, void *dest,
 // Copy bits [from..to) from src buffer into the blob at its current length
 // (i.e. 'to' is exclusive). Advance blob->length by (to - from). Return 0.
 static int blob_copy_bits(blob *dest, const void *src, size_t from, size_t to) {
+  size_t bits = to - from;
+  if (blob_ensure_capacity(dest, bits) < 0) return -1;
   int n = (int)from;
-  int m = (int)(to - 1); // inclusive
+  int m = (int)(to - 1);
   copy_bits_fast(src, dest->data, n, m, (int)dest->length);
-  dest->length += (to - from);
+  dest->length += bits;
   return 0;
 }
 
@@ -237,7 +239,6 @@ blob *blob_new_with_fill(size_t length_bits, int logical_value) {
   if (logical_value) {
     size_t bytes = b->capacity / 8;
     memset(b->data, 0xFF, bytes);
-    // Clear unused bits in last byte
     size_t used_bits = length_bits & 7;
     if (used_bits && bytes > 0) {
       uint8_t mask = (1 << used_bits) - 1;
@@ -247,6 +248,7 @@ blob *blob_new_with_fill(size_t length_bits, int logical_value) {
   return b;
 }
 
+
 void blob_destroy(blob *b) {
   if (!b) return;
   if (b->data) {
@@ -261,7 +263,7 @@ void blob_destroy(blob *b) {
 void blob_make_stone(blob *b) {
   if (!b) return;
   b->is_stone = 1;
-  // Optionally shrink buffer to exactly length bits
+  // shrink buffer to exactly length bits
   if (b->capacity > b->length) {
     size_t size_bytes = (b->length + 7) >> 3;
     if (size_bytes) {

source/qjs_blob.c

@@ -50,28 +50,32 @@ static JSValue js_blob_constructor(JSContext *ctx, JSValueConst new_target,
       int is_one = JS_ToBool(ctx, argv[1]);
       bd = blob_new_with_fill((size_t)length_bits, is_one);
     } else if (JS_IsFunction(ctx, argv[1])) {
-      // Random function provided - call it for each bit
+      /* Random function provided – call it for each bit */
+      size_t bytes = (length_bits + 7) / 8;
       bd = blob_new((size_t)length_bits);
       if (bd) {
         bd->length = length_bits;
+        /* Ensure the backing storage starts out zeroed */
+        memset(bd->data, 0, bytes);
         for (size_t i = 0; i < length_bits; i++) {
           JSValue randval = JS_Call(ctx, argv[1], JS_UNDEFINED, 0, NULL);
           if (JS_IsException(randval)) {
             blob_destroy(bd);
             return JS_EXCEPTION;
           }
-          int64_t fitval;
-          JS_ToInt64(ctx, &fitval, randval);
+    
+          int32_t fitval;
+          JS_ToInt32(ctx, &fitval, randval);
           JS_FreeValue(ctx, randval);
-          
-          // Set bit based on random value
+    
+          /* Compute which byte and which bit within that byte to set/clear */
           size_t byte_idx = i / 8;
-          size_t bit_idx = i % 8;
-          if (fitval & 1) {
-            bd->data[byte_idx] |= (1 << bit_idx);
-          } else {
-            bd->data[byte_idx] &= ~(1 << bit_idx);
-          }
+          size_t bit_idx  = i % 8;
+    
+          if (fitval & 1)
+            bd->data[byte_idx] |= (uint8_t)(1 << bit_idx);
+          else
+            bd->data[byte_idx] &= (uint8_t)~(1 << bit_idx);
         }
       }
     } else {
@@ -232,14 +236,14 @@ static JSValue js_blob_read_logical(JSContext *ctx, JSValueConst this_val,
   }
   int64_t pos;
   if (JS_ToInt64(ctx, &pos, argv[0]) < 0) {
-    return JS_EXCEPTION;
+    return JS_ThrowInternalError(ctx, "must provide a positive bit");
   }
   if (pos < 0) {
-    return JS_NULL; // out of range
+    return JS_ThrowRangeError(ctx, "read_logical: position must be non-negative");
   }
   int bit_val;
   if (blob_read_bit(bd, (size_t)pos, &bit_val) < 0) {
-    return JS_NULL; // not stone or out of range
+    return JS_ThrowTypeError(ctx, "read_logical: blob must be stone");
   }
   return JS_NewBool(ctx, bit_val);
 }
@@ -284,22 +288,21 @@ static JSValue js_blob_read_number(JSContext *ctx, JSValueConst this_val,
   }
   blob *bd = js2blob(ctx, this_val);
   if (!bd) {
-    return JS_ThrowTypeError(ctx, "read_dec64: not called on a blob");
+    return JS_ThrowTypeError(ctx, "read_number: not called on a blob");
   }
   
   if (!bd->is_stone) {
-    return JS_ThrowTypeError(ctx, "read_dec64: blob must be stone");
+    return JS_ThrowTypeError(ctx, "read_number: blob must be stone");
   }
   
   double from;
   if (JS_ToFloat64(ctx, &from, argv[0]) < 0) return JS_EXCEPTION;
   
-  if (from < 0) return JS_ThrowRangeError(ctx, "read_dec64: out of range");
+  if (from < 0) return JS_ThrowRangeError(ctx, "read_number: position must be non-negative");
   
   double d;
-  printf("reading blob from %g\n", from);
   if (blob_read_dec64(bd, from, &d) < 0) {
-    return JS_ThrowRangeError(ctx, "read_dec64: out of range");
+    return JS_ThrowRangeError(ctx, "read_number: out of range");
   }
   
   return JS_NewFloat64(ctx, d);

source/qjs_crypto.c

@@ -199,6 +199,16 @@ JSValue js_crypto_random(JSContext *js, JSValue self, int argc, JSValue *argv)
   return JS_NewFloat64(js, val);
 }
 
+JSValue js_crypto_random_fit(JSContext *js, JSValue self, int argc, JSValue *argv)
+{
+  int32_t r;
+  if (randombytes(&r, sizeof(r)) != 0) {
+    return JS_ThrowInternalError(js, "crypto.random: unable to get random bytes");
+  }
+
+  return JS_NewInt32(js, r);
+}
+
 JSValue js_crypto_hash(JSContext *js, JSValue self, int argc, JSValue *argv)
 {
     if (argc < 1)
@@ -237,6 +247,7 @@ static const JSCFunctionListEntry js_crypto_funcs[] = {
   JS_CFUNC_DEF("keypair", 0, js_crypto_keypair),
   JS_CFUNC_DEF("shared", 1, js_crypto_shared),
   JS_CFUNC_DEF("random", 0, js_crypto_random),
+  JS_CFUNC_DEF("random_fit", 0, js_crypto_random_fit),
   JS_CFUNC_DEF("hash", 2, js_crypto_hash),
 };
 

tests/blob.ce

@@ -58,13 +58,27 @@ test("Write and read single bit", function() {
     assertEqual(b.read_logical(3), false, "Fourth bit should be false (0)");
 });
 
-// Test 4: Out of range read returns null
-test("Out of range read returns null", function() {
+// Test 4: Out of range read throws error
+test("Out of range read throws error", function() {
     var b = new Blob();
     b.write_bit(true);
     b.stone();
-    assertEqual(b.read_logical(100), null, "Out of range read should return null");
-    assertEqual(b.read_logical(-1), null, "Negative index read should return null");
+    
+    var threw = false;
+    try {
+        b.read_logical(100); // Out of range
+    } catch (e) {
+        threw = true;
+    }
+    assert(threw, "Out of range read should throw");
+    
+    threw = false;
+    try {
+        b.read_logical(-1); // Negative index
+    } catch (e) {
+        threw = true;
+    }
+    assert(threw, "Negative index read should throw");
 });
 
 // Test 5: Write and read numbers
@@ -314,6 +328,14 @@ test("Non-stone blob read methods should throw", function() {
     
     // Try to read without stoning - should throw
     var threw = false;
+    try {
+        b.read_logical(0);
+    } catch (e) {
+        threw = true;
+    }
+    assert(threw, "read_logical on non-stone blob should throw");
+    
+    threw = false;
     try {
         b.read_number(0);
     } catch (e) {