diff --git a/src/lib.rs b/src/lib.rs
index 21ffb29..4eb2717 100644
--- a/src/lib.rs
+++ b/src/lib.rs
@@ -690,642 +690,3 @@ impl<'a> StyleSheetParser<'a> {
         std::process::exit(1);
     }
 }
-
-#[cfg(test)]
-macro_rules! test {
-    ($func:ident, $input:literal) => {
-        #[test]
-        fn $func() {
-            let mut buf = Vec::new();
-            StyleSheet::new($input)
-                .expect(concat!("failed to parse on ", $input))
-                .print_as_css(&mut buf)
-                .expect(concat!("failed to pretty print on ", $input));
-            assert_eq!(
-                String::from($input),
-                String::from_utf8(buf).expect("produced invalid utf8")
-            );
-        }
-    };
-    ($func:ident, $input:literal, $output:literal) => {
-        #[test]
-        fn $func() {
-            let mut buf = Vec::new();
-            StyleSheet::new($input)
-                .expect(concat!("failed to parse on ", $input))
-                .print_as_css(&mut buf)
-                .expect(concat!("failed to pretty print on ", $input));
-            assert_eq!(
-                String::from($output),
-                String::from_utf8(buf).expect("produced invalid utf8")
-            );
-        }
-    };
-}
-
-#[cfg(test)]
-mod test_variables {
-    use super::StyleSheet;
-    test!(
-        basic_variable,
-        "$height: 1px;\na {\n  height: $height;\n}\n",
-        "a {\n  height: 1px;\n}\n"
-    );
-    test!(
-        variable_redeclaration,
-        "$a: 1px;\n$a: 2px;\na {\n  height: $a;\n}\n",
-        "a {\n  height: 2px;\n}\n"
-    );
-    test!(
-        variable_shadowing,
-        "$a: 1px;\n$b: $a;\na {\n  height: $b;\n}\n",
-        "a {\n  height: 1px;\n}\n"
-    );
-    test!(
-        variable_shadowing_val_does_not_change,
-        "$a: 1px;\n$b: $a; $a: 2px;\na {\n  height: $b;\n}\n",
-        "a {\n  height: 1px;\n}\n"
-    );
-    test!(
-        variable_shadowing_val_does_not_change_complex,
-        "a {\n  color: red;\n}\n$y: before;\n$x: 1 2 $y;\n$y: after;\nfoo {\n  a: $x;\n}",
-        "a {\n  color: red;\n}\nfoo {\n  a: 1 2 before;\n}\n"
-    );
-    test!(
-        variable_whitespace,
-        "$a   :    1px   ;\na {\n  height: $a;\n}\n",
-        "a {\n  height: 1px;\n}\n"
-    );
-    test!(
-        style_after_variable,
-        "$a: 1px;\na {\n  height: $a;\n  color: red;\n}\n",
-        "a {\n  height: 1px;\n  color: red;\n}\n"
-    );
-    test!(
-        literal_and_variable_as_val,
-        "$a: 1px;\na {\n  height: 1 $a;\n}\n",
-        "a {\n  height: 1 1px;\n}\n"
-    );
-    test!(
-        literal_and_variable_as_var,
-        "$a: 1px;\n$b: 1 $a;\na {\n  height: $b;\n}\n",
-        "a {\n  height: 1 1px;\n}\n"
-    );
-    test!(
-        eats_whitespace_after_variable_value,
-        "a {\n  b {\n    $c: red;\n  }\n  color: red;\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        variable_changes_through_new_ruleset,
-        "a {\n  $c: red;\nb {\n    $c: blue;\n  }\n  color: $c;\n}\n",
-        "a {\n  color: blue;\n}\n"
-    );
-    test!(
-        nested_interpolation,
-        "$a: red; a {\n  color: #{#{$a}};\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-}
-
-#[cfg(test)]
-mod test_selectors {
-    use super::StyleSheet;
-    test!(
-        selector_nesting_el_mul_el,
-        "a, b {\n  a, b {\n  color: red\n}\n}\n",
-        "a a, a b, b a, b b {\n  color: red;\n}\n"
-    );
-    test!(selector_element, "a {\n  color: red;\n}\n");
-    test!(selector_id, "#id {\n  color: red;\n}\n");
-    test!(selector_class, ".class {\n  color: red;\n}\n");
-    test!(selector_el_descendant, "a a {\n  color: red;\n}\n");
-    test!(selector_universal, "* {\n  color: red;\n}\n");
-    test!(selector_el_class_and, "a.class {\n  color: red;\n}\n");
-    test!(selector_el_id_and, "a#class {\n  color: red;\n}\n");
-    test!(
-        selector_el_class_descendant,
-        "a .class {\n  color: red;\n}\n"
-    );
-    test!(selector_el_id_descendant, "a #class {\n  color: red;\n}\n");
-    test!(
-        selector_el_universal_descendant,
-        "a * {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_universal_el_descendant,
-        "* a {\n  color: red;\n}\n"
-    );
-
-    test!(selector_attribute_any, "[attr] {\n  color: red;\n}\n");
-    test!(
-        selector_attribute_equals,
-        "[attr=val] {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_attribute_single_quotes,
-        "[attr='val'] {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_attribute_double_quotes,
-        "[attr=\"val\"] {\n  color: red;\n}\n"
-    );
-    test!(selector_attribute_in, "[attr~=val] {\n  color: red;\n}\n");
-    test!(
-        selector_attribute_begins_hyphen_or_exact,
-        "[attr|=val] {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_attribute_starts_with,
-        "[attr^=val] {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_attribute_ends_with,
-        "[attr$=val] {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_attribute_contains,
-        "[attr*=val] {\n  color: red;\n}\n"
-    );
-    test!(selector_el_attribute_and, "a[attr] {\n  color: red;\n}\n");
-    test!(
-        selector_el_attribute_descendant,
-        "a [attr] {\n  color: red;\n}\n"
-    );
-    test!(selector_el_mul_el, "a, b {\n  color: red;\n}\n");
-    test!(
-        selector_el_immediate_child_el,
-        "a > b {\n  color: red;\n}\n"
-    );
-    test!(selector_el_following_el, "a + b {\n  color: red;\n}\n");
-    test!(selector_el_preceding_el, "a ~ b {\n  color: red;\n}\n");
-    test!(selector_pseudo, ":pseudo {\n  color: red;\n}\n");
-    test!(selector_el_and_pseudo, "a:pseudo {\n  color: red;\n}\n");
-    test!(
-        selector_el_pseudo_descendant,
-        "a :pseudo {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_pseudo_el_descendant,
-        ":pseudo a {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_pseudo_paren_comma,
-        ":pseudo(a, b, c) {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_pseudo_paren_space,
-        ":pseudo(a b c) {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_el_pseudo_paren_and,
-        "a:pseudo(a, b, c) {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_el_pseudo_paren_descendant,
-        "a :pseudo(a, b, c) {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_pseudo_paren_el_descendant,
-        ":pseudo(a, b, c) a {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_pseudo_paren_el_nested,
-        "a {\n  :pseudo(a, b, c) {\n  color: red;\n  }\n}\n",
-        "a :pseudo(a, b, c) {\n  color: red;\n}\n"
-    );
-    test!(selector_mul, "a, b {\n  color: red;\n}\n");
-    test!(
-        outer_ampersand,
-        "a, b {\n& c {\n  color: red;\n}\n}\n",
-        "a c, b c {\n  color: red;\n}\n"
-    );
-    test!(
-        inner_ampersand,
-        "a, b {\na & c {\n  color: red;\n}\n}\n",
-        "a a c, a b c {\n  color: red;\n}\n"
-    );
-    test!(
-        ampersand_multiple_whitespace,
-        " a  ,  b   {\n&c {\n  color: red;\n}\n}\n",
-        "ac, bc {\n  color: red;\n}\n"
-    );
-    test!(
-        ampersand_alone,
-        "a, b {\n& {\n  color: red;\n}\n}\n",
-        "a, b {\n  color: red;\n}\n"
-    );
-    test!(
-        bem_dash_dash_selector,
-        "a {\n&--b {\n  color: red;\n}\n}\n",
-        "a--b {\n  color: red;\n}\n"
-    );
-    // test!(
-    //     bem_underscore_selector,
-    //     "a {\n&__b {\n  color: red;\n}\n}\n",
-    //     "a__b {\n  color: red;\n}\n"
-    // );
-    test!(
-        selector_interpolation_start,
-        "#{a}bc {\n  color: red;\n}\n",
-        "abc {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_interpolation_middle,
-        "a#{b}c {\n  color: red;\n}\n",
-        "abc {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_interpolation_end,
-        "ab#{c} {\n  color: red;\n}\n",
-        "abc {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_interpolation_variable,
-        "$a: foo;\nab#{$a} {\n  color: red;\n}\n",
-        "abfoo {\n  color: red;\n}\n"
-    );
-    test!(
-        selector_whitespace,
-        "  a  >  b  ,  c  ~  d  e  .f  #g  :h  i.j  [  k  ]  { color: red }",
-        "a > b, c ~ d e .f #g :h i.j [k] {\n  color: red;\n}\n"
-    );
-}
-
-#[cfg(test)]
-mod test_units {
-    use super::StyleSheet;
-    test!(unit_none, "a {\n  height: 1;\n}\n");
-    test!(unit_not_attached, "a {\n  height: 1 px;\n}\n");
-    test!(unit_px, "a {\n  height: 1px;\n}\n");
-    test!(unit_em, "a {\n  height: 1em;\n}\n");
-    test!(unit_rem, "a {\n  height: 1rem;\n}\n");
-    test!(unit_percent, "a {\n  height: 1%;\n}\n");
-}
-
-#[cfg(test)]
-mod test_comments {
-    use super::StyleSheet;
-    test!(
-        removes_inner_comments,
-        "a {\n  color: red/* hi */;\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        removes_inner_comments_whitespace,
-        "a {\n  color: red    /* hi */;\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        preserves_outer_comments_before,
-        "a {\n  /* hi */\n  color: red;\n}\n"
-    );
-    test!(
-        preserves_outer_comments_after,
-        "a {\n  color: red;\n  /* hi */\n}\n"
-    );
-    test!(
-        preserves_outer_comments_two,
-        "a {\n  /* foo */\n  /* bar */\n  color: red;\n}\n"
-    );
-    test!(
-        preserves_toplevel_comment_before,
-        "/* foo */\na {\n  color: red;\n}\n"
-    );
-    test!(
-        preserves_toplevel_comment_after,
-        "a {\n  color: red;\n}\n/* foo */\n"
-    );
-    test!(
-        removes_single_line_comment,
-        "// a { color: red }\na {\n  height: 1 1px;\n}\n",
-        "a {\n  height: 1 1px;\n}\n"
-    );
-}
-
-#[cfg(test)]
-mod test_styles {
-    use super::StyleSheet;
-    test!(basic_style, "a {\n  color: red;\n}\n");
-    test!(two_styles, "a {\n  color: red;\n  color: blue;\n}\n");
-    test!(
-        two_inner_rulesets,
-        "a {\n  b {\n  color: red;\n}\n  c {\n  color: white;\n}\n}\n",
-        "a b {\n  color: red;\n}\na c {\n  color: white;\n}\n"
-    );
-    test!(
-        two_rulesets,
-        "a {\n  color: red;\n}\nc {\n  color: white;\n}\n"
-    );
-    test!(
-        two_rulesets_first_no_semicolon,
-        "a {\n  color: red\n}\nc {\n  color: white;\n}\n",
-        "a {\n  color: red;\n}\nc {\n  color: white;\n}\n"
-    );
-    test!(
-        two_inner_outer_rulesets,
-        "a {\n  b {\n  color: red;\n}\n  c {\n  color: white;\n}\n}\na {\n  b {\n  color: red;\n}\n  c {\n  color: white;\n}\n}\n",
-        "a b {\n  color: red;\n}\na c {\n  color: white;\n}\na b {\n  color: red;\n}\na c {\n  color: white;\n}\n"
-    );
-    test!(
-        removes_empty_outer_styles,
-        "a {\n  b {\n    color: red;\n  }\n",
-        "a b {\n  color: red;\n}\n"
-    );
-    test!(removes_empty_styles, "a {}\n", "");
-    test!(
-        doesnt_eat_style_after_ruleset,
-        "a {\n  b {\n  color: red;\n}\n  color: blue;\n}\n",
-        "a {\n  color: blue;\n}\na b {\n  color: red;\n}\n"
-    );
-    test!(
-        multiline_style,
-        "a {\n  color: red\n  blue;\n}\n",
-        "a {\n  color: red blue;\n}\n"
-    );
-    test!(hyphenated_style_property, "a {\n  font-family: Arial;\n}\n");
-    test!(hyphenated_style_value, "a {\n  color: Open-Sans;\n}\n");
-    test!(
-        space_separated_style_value,
-        "a {\n  border: solid red;\n}\n"
-    );
-    test!(single_quoted_style_value, "a {\n  font: 'Open-Sans';\n}\n");
-    test!(
-        double_quoted_style_value,
-        "a {\n  font: \"Open-Sans\";\n}\n"
-    );
-    test!(
-        comma_style_value,
-        "a {\n  font: Open-Sans, sans-serif;\n}\n"
-    );
-    test!(
-        style_interpolation_start,
-        "a {\n  #{c}olor: red;\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        style_interpolation_middle,
-        "a {\n  co#{l}or: red;\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        style_interpolation_end,
-        "a {\n  colo#{r}: red;\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        style_interpolation_variable,
-        "$a: foo;\na {\n  co#{$a}lor: red;\n}\n",
-        "a {\n  cofoolor: red;\n}\n"
-    );
-    test!(
-        style_val_interpolation_start,
-        "a {\n  color: #{r}ed;\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        style_val_interpolation_middle,
-        "a {\n  color: r#{e}d;\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        style_val_interpolation_end,
-        "a {\n  color: re#{d};\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        style_val_interpolation_variable,
-        "$a: foo;\na {\n  color: r#{$a}ed;\n}\n",
-        "a {\n  color: rfooed;\n}\n"
-    );
-    test!(
-        style_whitespace,
-        "a {\n     color      :       red    ;    \n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        triple_nested_preceding_ruleset,
-        "a {\n  b {\n    foo: bar;\n    c {}\n  }\n}\n",
-        "a b {\n  foo: bar;\n}\n"
-    );
-    test!(
-        triple_nested_following_ruleset,
-        "a {\n  b {\n    c {}\n    foo: bar;\n  }\n}\n",
-        "a b {\n  foo: bar;\n}\n"
-    );
-}
-
-#[cfg(test)]
-mod test_misc {
-    use super::*;
-    // test!(
-    //     combines_hyphens,
-    //     "a {\n  foo: bar - baz;\n}\n",
-    //     "a {\n  foo: bar-baz;\n}\n"
-    // );
-    test!(does_not_combine_hyphens, "a {\n  foo: bar -baz;\n}\n");
-    test!(
-        ident_starts_with_hyphen,
-        "a {\n  foo: -webkit-bar-baz;\n}\n"
-    );
-    test!(ident_with_num, "el1 {\n  a: b;\n}\n");
-    test!(keyword_important, "a {\n  height: 1 !important;\n}\n");
-    test!(
-        keyword_important_uppercase,
-        "a {\n  height: 1 !IMPORTANT;\n}\n",
-        "a {\n  height: 1 !important;\n}\n"
-    );
-    test!(
-        keyword_important_not_at_end,
-        "a {\n  height: !important 1;\n}\n"
-    );
-}
-
-#[cfg(test)]
-mod test_mixins {
-    use super::*;
-    test!(
-        basic_mixin,
-        "@mixin a {\n  color: red;\n}\n\nb {\n  @include a;\n}\n",
-        "b {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_two_styles,
-        "@mixin a {\n  color: red;\n  color: blue;\n}\n\nb {\n  @include a;\n}\n",
-        "b {\n  color: red;\n  color: blue;\n}\n"
-    );
-    test!(
-        mixin_ruleset,
-        "@mixin a {\n  b {\n    color: red;\n  }\n}\nb {\n  @include a;\n}\n",
-        "b b {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_two_rulesets,
-        "@mixin a {\n  b {\n    color: red;\n  }\n  c {\n    color: blue;\n  }\n}\nd {\n  @include a;\n}\n",
-        "d b {\n  color: red;\n}\nd c {\n  color: blue;\n}\n"
-    );
-    test!(
-        mixin_ruleset_and_style,
-        "@mixin a {\n  b {\n    color: red;\n  }\n  color: blue;\n}\nd {\n  @include a;\n}\n",
-        "d {\n  color: blue;\n}\nd b {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_style_and_ruleset,
-        "@mixin a {\n  color: blue;\n  b {\n    color: red;\n}\n}\nd {\n  @include a;\n}\n",
-        "d {\n  color: blue;\n}\nd b {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_nested_rulesets,
-        "@mixin a {\n  b {\n    c {\n      color: red;\n}\n}\n}\nd {\n  @include a;\n}\n",
-        "d b c {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_removes_empty_ruleset,
-        "@mixin a {\n  color:red; b {\n}\n}\nd {\n  @include a;\n}\n",
-        "d {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_variable_scope_one_ruleset,
-        "@mixin a {\n  $a: blue;\nb {\n  $a: red;\n}  color: $a\n}\nd {\n  @include a;\n}\n",
-        "d {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_single_arg,
-        "@mixin a($b) {\n  color: $b;\n}\nd {\n  @include a(red);\n}\n",
-        "d {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_two_args,
-        "@mixin a($b, $c) {\n  color: $b;\n  color: $c\n}\nd {\n  @include a(red, blue);\n}\n",
-        "d {\n  color: red;\n  color: blue;\n}\n"
-    );
-    test!(
-        mixin_arg_trailing_comma,
-        "@mixin a($b, $c,) {\n  color: $b;\n  color: $c\n}\nd {\n  @include a(red, blue);\n}\n",
-        "d {\n  color: red;\n  color: blue;\n}\n"
-    );
-    test!(
-        mixin_property_interpolation,
-        "@mixin a($b) {\n  #{$b}: red;\n}\nd {\n  @include a(color);\n}\n",
-        "d {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_style_interpolation,
-        "@mixin a($b) {\n  color: #{$b};\n}\nd {\n  @include a(red);\n}\n",
-        "d {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_simple_default_value,
-        "@mixin a($b: red) {\n  color: $b;\n}\nd {\n  @include a;\n}\n",
-        "d {\n  color: red;\n}\n"
-    );
-    test!(
-        mixin_second_value_default,
-        "@mixin a($a, $b: blue) {\n  color: $a $b;\n}\nd {\n  @include a(red);\n}\n",
-        "d {\n  color: red blue;\n}\n"
-    );
-    test!(
-        mixin_two_default_values,
-        "@mixin a($a: red, $b: blue) {\n  color: $a $b;\n}\nd {\n  @include a;\n}\n",
-        "d {\n  color: red blue;\n}\n"
-    );
-    test!(
-        mixin_override_default_value_positionally,
-        "@mixin a($a: red) {\n  color: $a;\n}\nd {\n  @include a(blue);\n}\n",
-        "d {\n  color: blue;\n}\n"
-    );
-    test!(
-        mixin_keyword_arg,
-        "@mixin a($a) {\n  color: $a;\n}\nd {\n  @include a($a: blue);\n}\n",
-        "d {\n  color: blue;\n}\n"
-    );
-    test!(
-        mixin_keyword_arg_override_default,
-        "@mixin a($a: red) {\n  color: $a;\n}\nd {\n  @include a($a: blue);\n}\n",
-        "d {\n  color: blue;\n}\n"
-    );
-    test!(
-        mixin_keyword_applies_to_second_arg,
-        "@mixin a($a: red, $b) {\n  color: $a $b;\n}\nd {\n  @include a($b: blue);\n}\n",
-        "d {\n  color: red blue;\n}\n"
-    );
-    test!(
-        mixin_two_keywords,
-        "@mixin a($a, $b) {\n  color: $a $b;\n}\nd {\n  @include a($a: red, $b: blue);\n}\n",
-        "d {\n  color: red blue;\n}\n"
-    );
-    test!(
-        mixin_two_keywords_wrong_direction,
-        "@mixin a($a, $b) {\n  color: $a $b;\n}\nd {\n  @include a($b: blue, $a: red);\n}\n",
-        "d {\n  color: red blue;\n}\n"
-    );
-}
-
-#[cfg(test)]
-mod test_imports {
-    use super::*;
-    use tempfile::Builder;
-
-    macro_rules! test_import {
-        ($func:ident, $input:literal => $output:literal | $( $name:literal($content:literal) ),*) => {
-            #[test]
-            fn $func() {
-                $(
-                    let mut f = Builder::new().rand_bytes(0).prefix("").suffix($name).tempfile_in("").unwrap();
-                    write!(f, $content).unwrap();
-                )*
-                let mut buf = Vec::new();
-                StyleSheet::new($input)
-                .expect(concat!("failed to parse in "))
-                .print_as_css(&mut buf)
-                .expect(concat!("failed to pretty print on ", $input));
-                assert_eq!(
-                    String::from($output),
-                    String::from_utf8(buf).expect("produced invalid utf8")
-                );
-            }
-        }
-    }
-
-    // we have to use test name as filename because tests are run multithreaded in the same directory, so some names may conflict
-    test_import!(imports_variable, "@import \"imports_variable\";\na {\n color: $a;\n}" => "a {\n  color: red;\n}\n" | "imports_variable"("$a: red;"));
-    test_import!(single_quotes_import, "@import 'single_quotes_import';\na {\n color: $a;\n}" => "a {\n  color: red;\n}\n" | "single_quotes_import"("$a: red;"));
-    test_import!(finds_name_scss, "@import \"finds_name_scss\";\na {\n color: $a;\n}" => "a {\n  color: red;\n}\n" | "finds_name_scss.scss"("$a: red;"));
-    test_import!(finds_underscore_name_scss, "@import \"finds_underscore_name_scss\";\na {\n color: $a;\n}" => "a {\n  color: red;\n}\n" | "_finds_underscore_name_scss.scss"("$a: red;"));
-}
-
-#[cfg(test)]
-mod test_values {
-    use super::*;
-    test!(comma_list_ident, "a {\n  color: red, white, blue;\n}\n");
-    test!(space_list_ident, "a {\n  color: red white blue;\n}\n");
-    test!(comma_list_number, "a {\n  color: 1, 2, 3;\n}\n");
-    test!(space_list_number, "a {\n  color: 1 2 3;\n}\n");
-    test!(comma_space_list_number, "a {\n  color: 1 1, 2 2, 3 3;\n}\n");
-    test!(
-        whitespace_space_list_number,
-        "a {\n  color:  1  2  3  ;\n}\n",
-        "a {\n  color: 1 2 3;\n}\n"
-    );
-    test!(
-        whitespace_comma_list_number,
-        "a {\n  color:  1 ,  2 ,  3  ;\n}\n",
-        "a {\n  color: 1, 2, 3;\n}\n"
-    );
-    test!(number, "a {\n  color: 1;\n}\n");
-    test!(
-        removes_paren_around_single_value,
-        "a {\n  color: (red);\n}\n",
-        "a {\n  color: red;\n}\n"
-    );
-    test!(
-        removes_paren_around_space_list,
-        "a {\n  color: (red blue);\n}\n",
-        "a {\n  color: red blue;\n}\n"
-    );
-    test!(
-        removes_paren_around_item_in_list,
-        "a {\n  color: 1 (red blue);\n}\n",
-        "a {\n  color: 1 red blue;\n}\n"
-    );
-}
diff --git a/tests/main.rs b/tests/main.rs
new file mode 100644
index 0000000..ddbe9db
--- /dev/null
+++ b/tests/main.rs
@@ -0,0 +1,641 @@
+use grass::StyleSheet;
+
+#[cfg(test)]
+macro_rules! test {
+    ($func:ident, $input:literal) => {
+        #[test]
+        fn $func() {
+            let mut buf = Vec::new();
+            StyleSheet::new($input)
+                .expect(concat!("failed to parse on ", $input))
+                .print_as_css(&mut buf)
+                .expect(concat!("failed to pretty print on ", $input));
+            assert_eq!(
+                String::from($input),
+                String::from_utf8(buf).expect("produced invalid utf8")
+            );
+        }
+    };
+    ($func:ident, $input:literal, $output:literal) => {
+        #[test]
+        fn $func() {
+            let mut buf = Vec::new();
+            StyleSheet::new($input)
+                .expect(concat!("failed to parse on ", $input))
+                .print_as_css(&mut buf)
+                .expect(concat!("failed to pretty print on ", $input));
+            assert_eq!(
+                String::from($output),
+                String::from_utf8(buf).expect("produced invalid utf8")
+            );
+        }
+    };
+}
+
+#[cfg(test)]
+mod test_variables {
+    use super::*;
+    test!(
+        basic_variable,
+        "$height: 1px;\na {\n  height: $height;\n}\n",
+        "a {\n  height: 1px;\n}\n"
+    );
+    test!(
+        variable_redeclaration,
+        "$a: 1px;\n$a: 2px;\na {\n  height: $a;\n}\n",
+        "a {\n  height: 2px;\n}\n"
+    );
+    test!(
+        variable_shadowing,
+        "$a: 1px;\n$b: $a;\na {\n  height: $b;\n}\n",
+        "a {\n  height: 1px;\n}\n"
+    );
+    test!(
+        variable_shadowing_val_does_not_change,
+        "$a: 1px;\n$b: $a; $a: 2px;\na {\n  height: $b;\n}\n",
+        "a {\n  height: 1px;\n}\n"
+    );
+    test!(
+        variable_shadowing_val_does_not_change_complex,
+        "a {\n  color: red;\n}\n$y: before;\n$x: 1 2 $y;\n$y: after;\nfoo {\n  a: $x;\n}",
+        "a {\n  color: red;\n}\nfoo {\n  a: 1 2 before;\n}\n"
+    );
+    test!(
+        variable_whitespace,
+        "$a   :    1px   ;\na {\n  height: $a;\n}\n",
+        "a {\n  height: 1px;\n}\n"
+    );
+    test!(
+        style_after_variable,
+        "$a: 1px;\na {\n  height: $a;\n  color: red;\n}\n",
+        "a {\n  height: 1px;\n  color: red;\n}\n"
+    );
+    test!(
+        literal_and_variable_as_val,
+        "$a: 1px;\na {\n  height: 1 $a;\n}\n",
+        "a {\n  height: 1 1px;\n}\n"
+    );
+    test!(
+        literal_and_variable_as_var,
+        "$a: 1px;\n$b: 1 $a;\na {\n  height: $b;\n}\n",
+        "a {\n  height: 1 1px;\n}\n"
+    );
+    test!(
+        eats_whitespace_after_variable_value,
+        "a {\n  b {\n    $c: red;\n  }\n  color: red;\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        variable_changes_through_new_ruleset,
+        "a {\n  $c: red;\nb {\n    $c: blue;\n  }\n  color: $c;\n}\n",
+        "a {\n  color: blue;\n}\n"
+    );
+    test!(
+        nested_interpolation,
+        "$a: red; a {\n  color: #{#{$a}};\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+}
+
+#[cfg(test)]
+mod test_selectors {
+    use super::StyleSheet;
+    test!(
+        selector_nesting_el_mul_el,
+        "a, b {\n  a, b {\n  color: red\n}\n}\n",
+        "a a, a b, b a, b b {\n  color: red;\n}\n"
+    );
+    test!(selector_element, "a {\n  color: red;\n}\n");
+    test!(selector_id, "#id {\n  color: red;\n}\n");
+    test!(selector_class, ".class {\n  color: red;\n}\n");
+    test!(selector_el_descendant, "a a {\n  color: red;\n}\n");
+    test!(selector_universal, "* {\n  color: red;\n}\n");
+    test!(selector_el_class_and, "a.class {\n  color: red;\n}\n");
+    test!(selector_el_id_and, "a#class {\n  color: red;\n}\n");
+    test!(
+        selector_el_class_descendant,
+        "a .class {\n  color: red;\n}\n"
+    );
+    test!(selector_el_id_descendant, "a #class {\n  color: red;\n}\n");
+    test!(
+        selector_el_universal_descendant,
+        "a * {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_universal_el_descendant,
+        "* a {\n  color: red;\n}\n"
+    );
+
+    test!(selector_attribute_any, "[attr] {\n  color: red;\n}\n");
+    test!(
+        selector_attribute_equals,
+        "[attr=val] {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_attribute_single_quotes,
+        "[attr='val'] {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_attribute_double_quotes,
+        "[attr=\"val\"] {\n  color: red;\n}\n"
+    );
+    test!(selector_attribute_in, "[attr~=val] {\n  color: red;\n}\n");
+    test!(
+        selector_attribute_begins_hyphen_or_exact,
+        "[attr|=val] {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_attribute_starts_with,
+        "[attr^=val] {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_attribute_ends_with,
+        "[attr$=val] {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_attribute_contains,
+        "[attr*=val] {\n  color: red;\n}\n"
+    );
+    test!(selector_el_attribute_and, "a[attr] {\n  color: red;\n}\n");
+    test!(
+        selector_el_attribute_descendant,
+        "a [attr] {\n  color: red;\n}\n"
+    );
+    test!(selector_el_mul_el, "a, b {\n  color: red;\n}\n");
+    test!(
+        selector_el_immediate_child_el,
+        "a > b {\n  color: red;\n}\n"
+    );
+    test!(selector_el_following_el, "a + b {\n  color: red;\n}\n");
+    test!(selector_el_preceding_el, "a ~ b {\n  color: red;\n}\n");
+    test!(selector_pseudo, ":pseudo {\n  color: red;\n}\n");
+    test!(selector_el_and_pseudo, "a:pseudo {\n  color: red;\n}\n");
+    test!(
+        selector_el_pseudo_descendant,
+        "a :pseudo {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_pseudo_el_descendant,
+        ":pseudo a {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_pseudo_paren_comma,
+        ":pseudo(a, b, c) {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_pseudo_paren_space,
+        ":pseudo(a b c) {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_el_pseudo_paren_and,
+        "a:pseudo(a, b, c) {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_el_pseudo_paren_descendant,
+        "a :pseudo(a, b, c) {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_pseudo_paren_el_descendant,
+        ":pseudo(a, b, c) a {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_pseudo_paren_el_nested,
+        "a {\n  :pseudo(a, b, c) {\n  color: red;\n  }\n}\n",
+        "a :pseudo(a, b, c) {\n  color: red;\n}\n"
+    );
+    test!(selector_mul, "a, b {\n  color: red;\n}\n");
+    test!(
+        outer_ampersand,
+        "a, b {\n& c {\n  color: red;\n}\n}\n",
+        "a c, b c {\n  color: red;\n}\n"
+    );
+    test!(
+        inner_ampersand,
+        "a, b {\na & c {\n  color: red;\n}\n}\n",
+        "a a c, a b c {\n  color: red;\n}\n"
+    );
+    test!(
+        ampersand_multiple_whitespace,
+        " a  ,  b   {\n&c {\n  color: red;\n}\n}\n",
+        "ac, bc {\n  color: red;\n}\n"
+    );
+    test!(
+        ampersand_alone,
+        "a, b {\n& {\n  color: red;\n}\n}\n",
+        "a, b {\n  color: red;\n}\n"
+    );
+    test!(
+        bem_dash_dash_selector,
+        "a {\n&--b {\n  color: red;\n}\n}\n",
+        "a--b {\n  color: red;\n}\n"
+    );
+    // test!(
+    //     bem_underscore_selector,
+    //     "a {\n&__b {\n  color: red;\n}\n}\n",
+    //     "a__b {\n  color: red;\n}\n"
+    // );
+    test!(
+        selector_interpolation_start,
+        "#{a}bc {\n  color: red;\n}\n",
+        "abc {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_interpolation_middle,
+        "a#{b}c {\n  color: red;\n}\n",
+        "abc {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_interpolation_end,
+        "ab#{c} {\n  color: red;\n}\n",
+        "abc {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_interpolation_variable,
+        "$a: foo;\nab#{$a} {\n  color: red;\n}\n",
+        "abfoo {\n  color: red;\n}\n"
+    );
+    test!(
+        selector_whitespace,
+        "  a  >  b  ,  c  ~  d  e  .f  #g  :h  i.j  [  k  ]  { color: red }",
+        "a > b, c ~ d e .f #g :h i.j [k] {\n  color: red;\n}\n"
+    );
+}
+
+#[cfg(test)]
+mod test_units {
+    use super::StyleSheet;
+    test!(unit_none, "a {\n  height: 1;\n}\n");
+    test!(unit_not_attached, "a {\n  height: 1 px;\n}\n");
+    test!(unit_px, "a {\n  height: 1px;\n}\n");
+    test!(unit_em, "a {\n  height: 1em;\n}\n");
+    test!(unit_rem, "a {\n  height: 1rem;\n}\n");
+    test!(unit_percent, "a {\n  height: 1%;\n}\n");
+}
+
+#[cfg(test)]
+mod test_comments {
+    use super::StyleSheet;
+    test!(
+        removes_inner_comments,
+        "a {\n  color: red/* hi */;\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        removes_inner_comments_whitespace,
+        "a {\n  color: red    /* hi */;\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        preserves_outer_comments_before,
+        "a {\n  /* hi */\n  color: red;\n}\n"
+    );
+    test!(
+        preserves_outer_comments_after,
+        "a {\n  color: red;\n  /* hi */\n}\n"
+    );
+    test!(
+        preserves_outer_comments_two,
+        "a {\n  /* foo */\n  /* bar */\n  color: red;\n}\n"
+    );
+    test!(
+        preserves_toplevel_comment_before,
+        "/* foo */\na {\n  color: red;\n}\n"
+    );
+    test!(
+        preserves_toplevel_comment_after,
+        "a {\n  color: red;\n}\n/* foo */\n"
+    );
+    test!(
+        removes_single_line_comment,
+        "// a { color: red }\na {\n  height: 1 1px;\n}\n",
+        "a {\n  height: 1 1px;\n}\n"
+    );
+}
+
+#[cfg(test)]
+mod test_styles {
+    use super::StyleSheet;
+    test!(basic_style, "a {\n  color: red;\n}\n");
+    test!(two_styles, "a {\n  color: red;\n  color: blue;\n}\n");
+    test!(
+        two_inner_rulesets,
+        "a {\n  b {\n  color: red;\n}\n  c {\n  color: white;\n}\n}\n",
+        "a b {\n  color: red;\n}\na c {\n  color: white;\n}\n"
+    );
+    test!(
+        two_rulesets,
+        "a {\n  color: red;\n}\nc {\n  color: white;\n}\n"
+    );
+    test!(
+        two_rulesets_first_no_semicolon,
+        "a {\n  color: red\n}\nc {\n  color: white;\n}\n",
+        "a {\n  color: red;\n}\nc {\n  color: white;\n}\n"
+    );
+    test!(
+        two_inner_outer_rulesets,
+        "a {\n  b {\n  color: red;\n}\n  c {\n  color: white;\n}\n}\na {\n  b {\n  color: red;\n}\n  c {\n  color: white;\n}\n}\n",
+        "a b {\n  color: red;\n}\na c {\n  color: white;\n}\na b {\n  color: red;\n}\na c {\n  color: white;\n}\n"
+    );
+    test!(
+        removes_empty_outer_styles,
+        "a {\n  b {\n    color: red;\n  }\n",
+        "a b {\n  color: red;\n}\n"
+    );
+    test!(removes_empty_styles, "a {}\n", "");
+    test!(
+        doesnt_eat_style_after_ruleset,
+        "a {\n  b {\n  color: red;\n}\n  color: blue;\n}\n",
+        "a {\n  color: blue;\n}\na b {\n  color: red;\n}\n"
+    );
+    test!(
+        multiline_style,
+        "a {\n  color: red\n  blue;\n}\n",
+        "a {\n  color: red blue;\n}\n"
+    );
+    test!(hyphenated_style_property, "a {\n  font-family: Arial;\n}\n");
+    test!(hyphenated_style_value, "a {\n  color: Open-Sans;\n}\n");
+    test!(
+        space_separated_style_value,
+        "a {\n  border: solid red;\n}\n"
+    );
+    test!(single_quoted_style_value, "a {\n  font: 'Open-Sans';\n}\n");
+    test!(
+        double_quoted_style_value,
+        "a {\n  font: \"Open-Sans\";\n}\n"
+    );
+    test!(
+        comma_style_value,
+        "a {\n  font: Open-Sans, sans-serif;\n}\n"
+    );
+    test!(
+        style_interpolation_start,
+        "a {\n  #{c}olor: red;\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        style_interpolation_middle,
+        "a {\n  co#{l}or: red;\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        style_interpolation_end,
+        "a {\n  colo#{r}: red;\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        style_interpolation_variable,
+        "$a: foo;\na {\n  co#{$a}lor: red;\n}\n",
+        "a {\n  cofoolor: red;\n}\n"
+    );
+    test!(
+        style_val_interpolation_start,
+        "a {\n  color: #{r}ed;\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        style_val_interpolation_middle,
+        "a {\n  color: r#{e}d;\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        style_val_interpolation_end,
+        "a {\n  color: re#{d};\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        style_val_interpolation_variable,
+        "$a: foo;\na {\n  color: r#{$a}ed;\n}\n",
+        "a {\n  color: rfooed;\n}\n"
+    );
+    test!(
+        style_whitespace,
+        "a {\n     color      :       red    ;    \n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        triple_nested_preceding_ruleset,
+        "a {\n  b {\n    foo: bar;\n    c {}\n  }\n}\n",
+        "a b {\n  foo: bar;\n}\n"
+    );
+    test!(
+        triple_nested_following_ruleset,
+        "a {\n  b {\n    c {}\n    foo: bar;\n  }\n}\n",
+        "a b {\n  foo: bar;\n}\n"
+    );
+}
+
+#[cfg(test)]
+mod test_misc {
+    use super::*;
+    // test!(
+    //     combines_hyphens,
+    //     "a {\n  foo: bar - baz;\n}\n",
+    //     "a {\n  foo: bar-baz;\n}\n"
+    // );
+    test!(does_not_combine_hyphens, "a {\n  foo: bar -baz;\n}\n");
+    test!(
+        ident_starts_with_hyphen,
+        "a {\n  foo: -webkit-bar-baz;\n}\n"
+    );
+    test!(ident_with_num, "el1 {\n  a: b;\n}\n");
+    test!(keyword_important, "a {\n  height: 1 !important;\n}\n");
+    test!(
+        keyword_important_uppercase,
+        "a {\n  height: 1 !IMPORTANT;\n}\n",
+        "a {\n  height: 1 !important;\n}\n"
+    );
+    test!(
+        keyword_important_not_at_end,
+        "a {\n  height: !important 1;\n}\n"
+    );
+}
+
+#[cfg(test)]
+mod test_mixins {
+    use super::*;
+    test!(
+        basic_mixin,
+        "@mixin a {\n  color: red;\n}\n\nb {\n  @include a;\n}\n",
+        "b {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_two_styles,
+        "@mixin a {\n  color: red;\n  color: blue;\n}\n\nb {\n  @include a;\n}\n",
+        "b {\n  color: red;\n  color: blue;\n}\n"
+    );
+    test!(
+        mixin_ruleset,
+        "@mixin a {\n  b {\n    color: red;\n  }\n}\nb {\n  @include a;\n}\n",
+        "b b {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_two_rulesets,
+        "@mixin a {\n  b {\n    color: red;\n  }\n  c {\n    color: blue;\n  }\n}\nd {\n  @include a;\n}\n",
+        "d b {\n  color: red;\n}\nd c {\n  color: blue;\n}\n"
+    );
+    test!(
+        mixin_ruleset_and_style,
+        "@mixin a {\n  b {\n    color: red;\n  }\n  color: blue;\n}\nd {\n  @include a;\n}\n",
+        "d {\n  color: blue;\n}\nd b {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_style_and_ruleset,
+        "@mixin a {\n  color: blue;\n  b {\n    color: red;\n}\n}\nd {\n  @include a;\n}\n",
+        "d {\n  color: blue;\n}\nd b {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_nested_rulesets,
+        "@mixin a {\n  b {\n    c {\n      color: red;\n}\n}\n}\nd {\n  @include a;\n}\n",
+        "d b c {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_removes_empty_ruleset,
+        "@mixin a {\n  color:red; b {\n}\n}\nd {\n  @include a;\n}\n",
+        "d {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_variable_scope_one_ruleset,
+        "@mixin a {\n  $a: blue;\nb {\n  $a: red;\n}  color: $a\n}\nd {\n  @include a;\n}\n",
+        "d {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_single_arg,
+        "@mixin a($b) {\n  color: $b;\n}\nd {\n  @include a(red);\n}\n",
+        "d {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_two_args,
+        "@mixin a($b, $c) {\n  color: $b;\n  color: $c\n}\nd {\n  @include a(red, blue);\n}\n",
+        "d {\n  color: red;\n  color: blue;\n}\n"
+    );
+    test!(
+        mixin_arg_trailing_comma,
+        "@mixin a($b, $c,) {\n  color: $b;\n  color: $c\n}\nd {\n  @include a(red, blue);\n}\n",
+        "d {\n  color: red;\n  color: blue;\n}\n"
+    );
+    test!(
+        mixin_property_interpolation,
+        "@mixin a($b) {\n  #{$b}: red;\n}\nd {\n  @include a(color);\n}\n",
+        "d {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_style_interpolation,
+        "@mixin a($b) {\n  color: #{$b};\n}\nd {\n  @include a(red);\n}\n",
+        "d {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_simple_default_value,
+        "@mixin a($b: red) {\n  color: $b;\n}\nd {\n  @include a;\n}\n",
+        "d {\n  color: red;\n}\n"
+    );
+    test!(
+        mixin_second_value_default,
+        "@mixin a($a, $b: blue) {\n  color: $a $b;\n}\nd {\n  @include a(red);\n}\n",
+        "d {\n  color: red blue;\n}\n"
+    );
+    test!(
+        mixin_two_default_values,
+        "@mixin a($a: red, $b: blue) {\n  color: $a $b;\n}\nd {\n  @include a;\n}\n",
+        "d {\n  color: red blue;\n}\n"
+    );
+    test!(
+        mixin_override_default_value_positionally,
+        "@mixin a($a: red) {\n  color: $a;\n}\nd {\n  @include a(blue);\n}\n",
+        "d {\n  color: blue;\n}\n"
+    );
+    test!(
+        mixin_keyword_arg,
+        "@mixin a($a) {\n  color: $a;\n}\nd {\n  @include a($a: blue);\n}\n",
+        "d {\n  color: blue;\n}\n"
+    );
+    test!(
+        mixin_keyword_arg_override_default,
+        "@mixin a($a: red) {\n  color: $a;\n}\nd {\n  @include a($a: blue);\n}\n",
+        "d {\n  color: blue;\n}\n"
+    );
+    test!(
+        mixin_keyword_applies_to_second_arg,
+        "@mixin a($a: red, $b) {\n  color: $a $b;\n}\nd {\n  @include a($b: blue);\n}\n",
+        "d {\n  color: red blue;\n}\n"
+    );
+    test!(
+        mixin_two_keywords,
+        "@mixin a($a, $b) {\n  color: $a $b;\n}\nd {\n  @include a($a: red, $b: blue);\n}\n",
+        "d {\n  color: red blue;\n}\n"
+    );
+    test!(
+        mixin_two_keywords_wrong_direction,
+        "@mixin a($a, $b) {\n  color: $a $b;\n}\nd {\n  @include a($b: blue, $a: red);\n}\n",
+        "d {\n  color: red blue;\n}\n"
+    );
+}
+
+#[cfg(test)]
+mod test_imports {
+    use super::*;
+    use std::io::Write;
+    use tempfile::Builder;
+
+    macro_rules! test_import {
+        ($func:ident, $input:literal => $output:literal | $( $name:literal($content:literal) ),*) => {
+            #[test]
+            fn $func() {
+                $(
+                    let mut f = Builder::new().rand_bytes(0).prefix("").suffix($name).tempfile_in("").unwrap();
+                    write!(f, $content).unwrap();
+                )*
+                let mut buf = Vec::new();
+                StyleSheet::new($input)
+                .expect(concat!("failed to parse in "))
+                .print_as_css(&mut buf)
+                .expect(concat!("failed to pretty print on ", $input));
+                assert_eq!(
+                    String::from($output),
+                    String::from_utf8(buf).expect("produced invalid utf8")
+                );
+            }
+        }
+    }
+
+    // we have to use test name as filename because tests are run multithreaded in the same directory, so some names may conflict
+    test_import!(imports_variable, "@import \"imports_variable\";\na {\n color: $a;\n}" => "a {\n  color: red;\n}\n" | "imports_variable"("$a: red;"));
+    test_import!(single_quotes_import, "@import 'single_quotes_import';\na {\n color: $a;\n}" => "a {\n  color: red;\n}\n" | "single_quotes_import"("$a: red;"));
+    test_import!(finds_name_scss, "@import \"finds_name_scss\";\na {\n color: $a;\n}" => "a {\n  color: red;\n}\n" | "finds_name_scss.scss"("$a: red;"));
+    test_import!(finds_underscore_name_scss, "@import \"finds_underscore_name_scss\";\na {\n color: $a;\n}" => "a {\n  color: red;\n}\n" | "_finds_underscore_name_scss.scss"("$a: red;"));
+}
+
+#[cfg(test)]
+mod test_values {
+    use super::*;
+    test!(comma_list_ident, "a {\n  color: red, white, blue;\n}\n");
+    test!(space_list_ident, "a {\n  color: red white blue;\n}\n");
+    test!(comma_list_number, "a {\n  color: 1, 2, 3;\n}\n");
+    test!(space_list_number, "a {\n  color: 1 2 3;\n}\n");
+    test!(comma_space_list_number, "a {\n  color: 1 1, 2 2, 3 3;\n}\n");
+    test!(
+        whitespace_space_list_number,
+        "a {\n  color:  1  2  3  ;\n}\n",
+        "a {\n  color: 1 2 3;\n}\n"
+    );
+    test!(
+        whitespace_comma_list_number,
+        "a {\n  color:  1 ,  2 ,  3  ;\n}\n",
+        "a {\n  color: 1, 2, 3;\n}\n"
+    );
+    test!(number, "a {\n  color: 1;\n}\n");
+    test!(
+        removes_paren_around_single_value,
+        "a {\n  color: (red);\n}\n",
+        "a {\n  color: red;\n}\n"
+    );
+    test!(
+        removes_paren_around_space_list,
+        "a {\n  color: (red blue);\n}\n",
+        "a {\n  color: red blue;\n}\n"
+    );
+    test!(
+        removes_paren_around_item_in_list,
+        "a {\n  color: 1 (red blue);\n}\n",
+        "a {\n  color: 1 red blue;\n}\n"
+    );
+}