Add specs for string split

spec/core_functions/string/split.hrx

@@ -0,0 +1,179 @@
+<===> options.yml
+---
+:ignore_for:
+- libsass
+
+<===>
+================================================================================
+<===> empty/input.scss
+a {b: split("")}
+
+<===> empty/output.css
+a {
+  b: [""];
+}
+
+<===>
+================================================================================
+<===> separator/input.scss
+a {b: split("a, b, c", ", ")}
+
+<===> separator/output.css
+a {
+  b: ["a", "b", "c"];
+}
+
+<===>
+================================================================================
+<===> empty_separator/input.scss
+a {b: split("Helvetica", "")}
+
+<===> empty_separator/output.css
+a {
+  b: ["H", "e", "l", "v", "e", "t", "i", "c", "a"];
+}
+
+<===>
+================================================================================
+<===> separator_not_found/input.scss
+a {b: split("a, b, c", "&")}
+
+<===> separator_not_found/output.css
+a {
+  b: ["a, b, c"];
+}
+
+<===>
+================================================================================
+<===> limit/input.scss
+a {b: split("a, b, c, d", ", ", 2)}
+
+<===> limit/output.css
+a {
+  b: ["a", "b", "c, d"];
+}
+
+<===>
+================================================================================
+<===> limit_zero/input.scss
+a {b: split("a, b, c", ", ", 0)}
+
+<===> limit_zero/output.css
+a {
+  b: ["a, b, c"];
+}
+
+<===>
+================================================================================
+<===> double_width_character/input.scss
+// Sass treats strings as sequences of Unicode codepoint; it doesn't care if a
+// character is represented as two UTF-16 code units.
+a {b: split("👭a", "")}
+
+<===> double_width_character/output.css
+a {
+  b: ["👭", "a"];
+}
+
+<===>
+================================================================================
+<===> private_use_character/input.scss
+// Dart Sass emits private-use characters as escapes in expanded mode, but it
+// should stil treat them as single characters for the purpose of functions.
+a {b: split("\E000"), ""}
+
+<===> private_use_character/output.css
+a {
+  b: ["\E000"];
+}
+
+<===>
+================================================================================
+<===> named/input.scss
+a {b: split($string: "a/b/c", $separator: "/", $limit: 1)}
+
+<===> named/output.css
+a {
+  b: ["a", "b/c"];
+}
+
+<===>
+================================================================================
+<===> error/too_many_args/input.scss
+a {b: split("a/b/c", "/", 1, 3)}
+
+<===> error/too_many_args/error
+Error: Only 3 arguments allowed, but 4 were passed.
+1 | a {b: split("a/b/c", "/", 1, 3)}
+  |       ^^^^^^^^^^^^^^^^^^^^^^^^^ invocation
+  '
+  ,--> sass:string
+1 | @function split($string, $separator, $limit: null) {
+  |           ======================================== declaration
+  '
+  input.scss 1:7  root stylesheet
+
+<===>
+================================================================================
+<===> error/type/string/input.scss
+a {b: split(1, "%")}
+
+<===> error/type/string/error
+Error: $string: 1 is not a string.
+  ,
+1 | a {b: split(1, "%")}
+  |       ^^^^^^^^^^^^^
+  '
+  input.scss 1:7  root stylesheet
+
+<===>
+================================================================================
+<===> error/type/separator/input.scss
+a {b: split("1/2/3", /)}
+
+<===> error/type/separator/error
+Error: $separator: / is not a string.
+  ,
+1 | a {b: split("1/2/3", /)}
+  |       ^^^^^^^^^^^^^^^^^
+  '
+  input.scss 1:7  root stylesheet
+
+<===>
+================================================================================
+<===> error/type/limit/input.scss
+a {b: split("1/2/3", "/", "1")}
+
+<===> error/type/limit/error
+Error: $limit: "1" is not a number.
+  ,
+1 | a {b: split("1/2/3", "/", "1")}
+  |       ^^^^^^^^^^^^^^^^^^^^^^^^
+  '
+  input.scss 1:7  root stylesheet
+
+<===>
+================================================================================
+<===> error/decimal/input.scss
+a {b: split("1/2/3", "/", 0.5)}
+
+<===> error/decimal/error
+Error: $limit: 0.5 is not an int.
+  ,
+1 | a {b: split("1/2/3", "/", 0.5)}
+  |       ^^^^^^^^^^^^^^^^^^^^^^^
+  '
+  input.scss 1:7  root stylesheet
+
+<===>
+================================================================================
+<===> error/negative_limit/input.scss
+a {b: split("1/2/3", "/", -1)}
+
+<===> error/negative_limit/error
+Error: $limit: Must be a positive int or null.
+  ,
+1 | a {b: split("1/2/3", "/", -1)}
+  |       ^^^^^^^^^^^^^^^^^^^^^^^
+  '
+  input.scss 1:7  root stylesheet