json/schema: add multipleOf test cases

json/schema/base.cpp

@@ -35,6 +35,7 @@ base::instantiate (std::string const &name, ::json::tree::node const &def)
     if (name == "minimum")              return std::make_unique<minimum> (def);
     if (name == "exclusiveMaximum")     return std::make_unique<exclusive_maximum> (def);
     if (name == "exclusiveMinimum")     return std::make_unique<exclusive_minimum> (def);
+    if (name == "multipleOf")           return std::make_unique<multiple_of > (def);
     if (name == "maximum")              return std::make_unique<maximum> (def);
     if (name == "properties")           return std::make_unique<properties> (def);
     if (name == "patternProperties")    return std::make_unique<pattern_properties> (def);

json/schema/inequality.cpp

@@ -75,3 +75,16 @@ template class util::json::schema::constraint::inequality<std::less_equal>;
 template class util::json::schema::constraint::inequality<std::greater_equal>;
 template class util::json::schema::constraint::inequality<std::less>;
 template class util::json::schema::constraint::inequality<std::greater>;
+
+
+///////////////////////////////////////////////////////////////////////////////
+template <>
+bool
+util::json::schema::constraint::is_multiple<double>::operator() (double a, double b) const noexcept
+{
+    return std::fmod (a, b) <= 1e-8;
+}
+
+
+//-----------------------------------------------------------------------------
+template class util::json::schema::constraint::inequality<util::json::schema::constraint::is_multiple>;

json/schema/inequality.hpp

@@ -48,4 +48,14 @@ namespace util::json::schema::constraint {
     using maximum = inequality<std::less_equal>;
     using exclusive_minimum = inequality<std::greater>;
     using exclusive_maximum = inequality<std::less>;
+
+
+    // this is not technically an inequality, but the implementation fits in
+    // nicely here.
+    template <typename T>
+    struct is_multiple {
+        bool operator() (T, T) const noexcept;
+    };
+
+    using multiple_of = inequality<is_multiple>;
 }

test/json/schema/parsing/bad/0000_multipleOf_zero.json

@@ -0,0 +1,4 @@
+{
+    "description": "multipleOf must be strictly greater than zero",
+    "multipleOf": 0
+}

test/json/schema/parsing/bad/0001_multipleOf_negative.json

@@ -0,0 +1,4 @@
+{
+    "description": "multipleOf must be strictly greater than zero",
+    "multipleOf": -1
+}

test/json/schema/validation/2004_multiple_of/bad/0000_integer.json

@@ -0,0 +1 @@
+1

test/json/schema/validation/2004_multiple_of/good/0000_zero.input.json

@@ -0,0 +1 @@
+0

test/json/schema/validation/2004_multiple_of/good/1000_identity.input.json

@@ -0,0 +1 @@
+1.5

test/json/schema/validation/2004_multiple_of/good/2000_ten_times.input.json

@@ -0,0 +1 @@
+15

test/json/schema/validation/2004_multiple_of/schema.json

@@ -0,0 +1 @@
+{ "type": "number", "multipleOf": 1.5 }