anb-parsing.html - mozsearch

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This WPT test may be referenced by the following Test IDs:
- /css/css-syntax/anb-parsing.html - WPT Dashboard Interop Dashboard

<!doctype html>

<title>An+B Parsing</title>

<script src="/resources/testharness.js"></script>

<script src="/resources/testharnessreport.js"></script>

<style>

foo { color: blue; }

</style>

<meta name="author" title="Tab Atkins-Bittner">

<link rel=help href="https://drafts.csswg.org/css-syntax/#the-anb-type">

<script>

function roundtripANB(str) {

    const rule = document.styleSheets[0].cssRules[0];

    rule.selectorText = "foo";

    rule.selectorText = `:nth-child(${str})`;

    // Check for parse error.

    if(rule.selectorText == "foo") return "parse error";

    return rule.selectorText.slice(11, -1);

function testANB(input, expected) {

    test(()=>{

        assert_equals(roundtripANB(input), expected);

    }, `"${input}" becomes "${expected}"`);

/* Just going down all the syntax clauses one-by-one */

//  odd | even |

testANB("odd", "2n+1");

testANB("even", "2n");

//  <integer> |

testANB("1", "1");

testANB("+1", "1");

testANB("-1", "-1");

//

//  <n-dimension> |

testANB("5n", "5n");

testANB("5N", "5n");

//  '+'?† n |

testANB("+n", "n");

testANB("n", "n");

testANB("N", "n");

testANB("+ n", "parse error");

//  -n |

testANB("-n", "-n");

testANB("-N", "-n");

//

//  <ndashdigit-dimension> |

testANB("5n-5", "5n-5");

//  '+'?† <ndashdigit-ident> |

testANB("+n-5", "n-5");

testANB("n-5", "n-5");

testANB("+ n-5", "parse error");

//  <dashndashdigit-ident> |

testANB("-n-5", "-n-5");

//

//  <n-dimension> <signed-integer> |

testANB("5n +5", "5n+5");

testANB("5n -5", "5n-5");

//  '+'?† n <signed-integer> |

testANB("+n +5", "n+5");

testANB("n +5", "n+5");

testANB("+n -5", "n-5");

testANB("+ n +5", "parse error");

testANB("n 5", "parse error");

//  -n <signed-integer> |

testANB("-n +5", "-n+5");

testANB("-n -5", "-n-5");

testANB("-n 5", "parse error");

//

//  <ndash-dimension> <signless-integer> |

testANB("5n- 5", "5n-5");

testANB("5n- -5", "parse error");

testANB("5n- +5", "parse error");

testANB("-5n- 5", "-5n-5");

//  '+'?† n- <signless-integer> |

testANB("+n- 5", "n-5");

testANB("n- 5", "n-5");

testANB("+ n- 5", "parse error");

testANB("n- +5", "parse error");

testANB("n- -5", "parse error");

//  -n- <signless-integer> |

testANB("-n- 5", "-n-5");

testANB("-n- +5", "parse error");

testANB("-n- -5", "parse error");

//

//  <n-dimension> ['+' | '-'] <signless-integer>

testANB("5n + 5", "5n+5");

testANB("5n - 5", "5n-5");

testANB("5n + +5", "parse error");

testANB("5n + -5", "parse error");

testANB("5n - +5", "parse error");

testANB("5n - -5", "parse error");

//  '+'?† n ['+' | '-'] <signless-integer> |

testANB("+n + 5", "n+5");

testANB("n + 5", "n+5");

testANB("+ n + 5", "parse error");

testANB("+n - 5", "n-5");

testANB("+n + +5", "parse error");

testANB("+n + -5", "parse error");

testANB("+n - +5", "parse error");

testANB("+n - -5", "parse error");

//  -n ['+' | '-'] <signless-integer>

testANB("-n + 5", "-n+5");

testANB("-n - 5", "-n-5");

testANB("-n + +5", "parse error");

testANB("-n + -5", "parse error");

testANB("-n - +5", "parse error");

testANB("-n - -5", "parse error");

/* Swapped ordering is invalid */

testANB("1 - n", "parse error");

testANB("0 - n", "parse error");

testANB("-1 + n", "parse error");

/* Odd space usage */

testANB("2 n + 2", "parse error");

testANB("- 2n", "parse error");

testANB("+ 2n", "parse error");

testANB("+2 n", "parse error");

</script>