<===> unquote/input.scss
@use "sass:string";
a {b: string.unquote("c")}

<===> unquote/output.css
a {
  b: c;
}

<===>
================================================================================
<===> quote/input.scss
@use "sass:string";
a {b: string.quote(c)}

<===> quote/output.css
a {
  b: "c";
}

<===>
================================================================================
<===> length/input.scss
@use "sass:string";
a {b: string.length("c")}

<===> length/output.css
a {
  b: 1;
}

<===>
================================================================================
<===> insert/input.scss
@use "sass:string";
a {b: string.insert("c", "d", 1)}

<===> insert/output.css
a {
  b: "dc";
}

<===>
================================================================================
<===> index/input.scss
@use "sass:string";
a {b: string.index("c", "c")}

<===> index/output.css
a {
  b: 1;
}

<===>
================================================================================
<===> slice/input.scss
@use "sass:string";
a {b: string.slice("c", 1, 1)}

<===> slice/output.css
a {
  b: "c";
}

<===>
================================================================================
<===> to_upper_case/input.scss
@use "sass:string";
a {b: string.to-upper-case("c")}

<===> to_upper_case/output.css
a {
  b: "C";
}

<===>
================================================================================
<===> unique_id/input.scss
@use "sass:meta";
@use "sass:string";
a {b: meta.type-of(string.unique-id())}

<===> unique_id/output.css
a {
  b: string;
}

<===>
================================================================================
<===> error/str_length/input.scss
@use "sass:string";
a {b: string.str-length("c")}

<===> error/str_length/error
Error: Undefined function.
  ,
2 | a {b: string.str-length("c")}
  |       ^^^^^^^^^^^^^^^^^^^^^^
  '
  input.scss 2:7  root stylesheet

<===>
================================================================================
<===> error/str_insert/input.scss
@use "sass:string";
a {b: string.str-insert("c", 1, "d")}

<===> error/str_insert/error
Error: Undefined function.
  ,
2 | a {b: string.str-insert("c", 1, "d")}
  |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^^^^
  '
  input.scss 2:7  root stylesheet

<===>
================================================================================
<===> error/str_index/input.scss
@use "sass:string";
a {b: string.str-index("c", "c")}

<===> error/str_index/error
Error: Undefined function.
  ,
2 | a {b: string.str-index("c", "c")}
  |       ^^^^^^^^^^^^^^^^^^^^^^^^^^
  '
  input.scss 2:7  root stylesheet

<===>
================================================================================
<===> error/str_slice/input.scss
@use "sass:string";
a {b: string.str-slice("c", 1, 1)}

<===> error/str_slice/error
Error: Undefined function.
  ,
2 | a {b: string.str-slice("c", 1, 1)}
  |       ^^^^^^^^^^^^^^^^^^^^^^^^^^^
  '
  input.scss 2:7  root stylesheet