Add a truckload of tests for <track-size> and <track-list>

tests/unit/style/parsing/mod.rs

@@ -5,10 +5,16 @@
 //! Tests for parsing and serialization of values/properties
 
 use cssparser::Parser;
+use euclid::size::TypedSize2D;
 use media_queries::CSSErrorReporterTest;
 use style::context::QuirksMode;
+use style::font_metrics::ServoMetricsProvider;
+use style::media_queries::{Device, MediaType};
 use style::parser::{PARSING_MODE_DEFAULT, ParserContext};
+use style::properties::{ComputedValues, StyleBuilder};
 use style::stylesheets::{CssRuleType, Origin};
+use style::values::computed::{Context, ToComputedValue};
+use style_traits::ToCss;
 
 fn parse<T, F: Fn(&ParserContext, &mut Parser) -> Result<T, ()>>(f: F, s: &str) -> Result<T, ()> {
     let url = ::servo_url::ServoUrl::parse("http://localhost").unwrap();
@@ -24,6 +30,32 @@ fn parse_entirely<T, F: Fn(&ParserContext, &mut Parser) -> Result<T, ()>>(f: F,
     parse(|context, parser| parser.parse_entirely(|p| f(context, p)), s)
 }
 
+fn assert_computed_serialization<C, F, T>(f: F, input: &str, output: &str)
+    where F: Fn(&ParserContext, &mut Parser) -> Result<T, ()>,
+          T: ToComputedValue<ComputedValue=C>, C: ToCss
+{
+    let viewport_size = TypedSize2D::new(0., 0.);
+    let initial_style = ComputedValues::initial_values();
+    let device = Device::new(MediaType::Screen, viewport_size);
+
+    let context = Context {
+        is_root_element: true,
+        device: &device,
+        inherited_style: initial_style,
+        layout_parent_style: initial_style,
+        style: StyleBuilder::for_derived_style(&initial_style),
+        cached_system_font: None,
+        font_metrics_provider: &ServoMetricsProvider,
+        in_media_query: false,
+        quirks_mode: QuirksMode::NoQuirks,
+    };
+
+    let parsed = parse(f, input).unwrap();
+    let computed = parsed.to_computed_value(&context);
+    let serialized = ToCss::to_css_string(&computed);
+    assert_eq!(serialized, output);
+}
+
 // This is a macro so that the file/line information
 // is preserved in the panic
 macro_rules! assert_roundtrip_with_context {