[Core] Add set_safe method to Array and Dictionary

This returns an error, making it possible to check the behavior

Also adds range checking for `Array.set` to match `Vector` and allow it
to be use safely

core/variant/array.cpp

@@ -428,9 +428,20 @@ void Array::set(int p_idx, const Variant &p_value) {
 	Variant value = p_value;
 	ERR_FAIL_COND(!_p->typed.validate(value, "set"));
 
+	ERR_FAIL_INDEX(p_idx, size());
 	operator[](p_idx) = value;
 }
 
+Error Array::set_safe(int p_idx, const Variant &p_value) {
+	ERR_FAIL_COND_V_MSG(_p->read_only, ERR_LOCKED, "Array is in read-only state.");
+	Variant value = p_value;
+	ERR_FAIL_COND_V(!_p->typed.validate(value, "set"), ERR_INVALID_PARAMETER);
+
+	ERR_FAIL_INDEX_V(p_idx, size(), ERR_PARAMETER_RANGE_ERROR);
+	operator[](p_idx) = value;
+	return OK;
+}
+
 const Variant &Array::get(int p_idx) const {
 	return operator[](p_idx);
 }

core/variant/array.h

@@ -116,6 +116,7 @@ class Array {
 	const Variant &operator[](int p_idx) const;
 
 	void set(int p_idx, const Variant &p_value);
+	Error set_safe(int p_idx, const Variant &p_value);
 	const Variant &get(int p_idx) const;
 
 	int size() const;

core/variant/dictionary.cpp

@@ -130,6 +130,14 @@ void Dictionary::set(const Variant &p_key, const Variant &p_value) {
 	operator[](key) = p_value;
 }
 
+Error Dictionary::set_safe(const Variant &p_key, const Variant &p_value) {
+	ERR_FAIL_COND_V_MSG(_p->read_only, ERR_LOCKED, "Dictionary is in read-only state.");
+	Variant key = p_key;
+	ERR_FAIL_COND_V(!_p->typed_key.validate(key, "set_safe"), ERR_INVALID_PARAMETER);
+	operator[](key) = p_value;
+	return OK;
+}
+
 Variant Dictionary::get_valid(const Variant &p_key) const {
 	Variant key = p_key;
 	ERR_FAIL_COND_V(!_p->typed_key.validate(key, "get_valid"), Variant());

core/variant/dictionary.h

@@ -57,6 +57,7 @@ class Dictionary {
 	Variant *getptr(const Variant &p_key);
 
 	void set(const Variant &p_key, const Variant &p_value);
+	Error set_safe(const Variant &p_key, const Variant &p_value);
 	Variant get_valid(const Variant &p_key) const;
 	Variant get(const Variant &p_key, const Variant &p_default) const;
 	Variant get_or_add(const Variant &p_key, const Variant &p_default);

tests/core/variant/test_dictionary.h

@@ -101,6 +101,9 @@ TEST_CASE("[Dictionary] Assignment using bracket notation ([])") {
 	map.set("This key does not exist", String());
 	CHECK_FALSE(map.has("This key does not exist"));
 	CHECK(map.size() == length);
+
+	CHECK(map.set_safe("This key does not exist", String()) == ERR_LOCKED);
+	CHECK(map.size() == length);
 	ERR_PRINT_ON;
 }