System.InvalidCastException when parsing a css

[jogibear9988]

Bug Report

When parsing CSS I get this exception:

System.InvalidCastException: 'Unable to cast object of type 'AngleSharp.Css.Values.CssReferenceValue' to type 'AngleSharp.Css.Values.CssTupleValue'.'

Prerequisites

• [x] Can you reproduce the problem in a MWE?
• [x] Are you running the latest version of AngleSharp?
• [x] Did you check the FAQs to see if that helps you?
• [x] Are you reporting to the correct repository? (there are multiple AngleSharp libraries, e.g., AngleSharp.Css for CSS support)
• [ ] Did you perform a search in the issues?

For more information, see the CONTRIBUTING guide.

Description

[Description of the bug]

Steps to Reproduce

1. Try to parse with this code:

                                   var parser = new CssParser();
                                   var ss = parser.ParseStyleSheet(css);
                                   var newCss = ss.ToCss(new AngleSharp.Css.MinifyStyleFormatter());
                                   result = newCss;

this css:

    :root {
        --header-height: 50px;
        --nav-width: 280px;
    }

    ol, ul {
        padding-left: 0;
    }

    * {
        margin: 0;
        padding: 0;
        box-sizing: border-box;
        word-wrap: normal;
        flex-wrap:  nowrap;
        white-space:  nowrap;
    }

    body {
        overflow: hidden;
        font-size: 14px;
        color: var(--kx-text);
    }

    /*input:-webkit-autofill {
        background-color: transparent !important;
    }*/

    paper-input-container {
        --paper-input-container-focus-color: #6F8A9D;
    }

    paper-input-container t-t {
        font-weight: normal;
    }

    #popuplayer {
        pointer-events: none;
        width: 100%;
        height: 100%;
    }

    .invisible {
        display: none !important;
    }

    .kardex-wrapper {
        height: 100vh;
        width: 100vw;
        display: grid;
        grid-template-rows: var(--header-height) 10px 1fr;
        grid-template-columns: var(--nav-width) 1fr;
        grid-template-areas: "navheader header" "navheader content" "nav content";
    }

    header {
        grid-area: header;
        font-family: KardexMOT-Light, sans-serif;
        background-color: var(--kx-bg);
        color: var(--kx-text-light);
        display: grid;
        grid-template-rows: var(--header-height);
        grid-template-columns: 1fr 1fr 1fr;
    }

    header.header-red {
        background-color: var(--kx-error) !important;
    }

    #configRibbonHeader.offline{
        border-bottom: 5px solid var(--kx-error) !important;
    }

    #header-left-column-wrapper {
        display: flex;
        align-items: center;
        z-index: 1;
        background: var(--kx-bg);
    }

    .hamburger {
        transform: scale(0.7);
    }

    .hamburger .hamburger-inner, .hamburger .hamburger-inner:before, .hamburger .hamburger-inner:after {
        background-color: var(--kx-text-light);
    }

    #mcc-header-logo {
        font-size: 24px;
        margin-top: -10px;
        font-weight: bold;
        cursor: pointer;
    }

    .mcc-transparent-button:hover {
        opacity: 0.7;
        cursor: pointer;
    }

    #header-middle-column-wrapper {
        display: flex;
        justify-content: center;
        align-items: center;
        font-size: 30px;
        margin-top: -6px;
    }

    #header-right-column-wrapper {
        display: flex;
        justify-content: flex-end;
        align-items: center;
    }

    #alarmbell-wrapper {
        cursor: pointer;
        position: relative;
        font-size: 12px;
    }

    .alarmbadge {
        position: absolute;
        display: inline-block;
        line-height: 0px;
        border-radius: 50%;
        font-size: 12px;
        font-family: Open Sans;
        background-color: #ffffff;
        top: -4px;
        right: -4px;
        background: var(--kx-error);
        color: white;
        font-weight: bolder;
        min-width: 16px;
        text-align: center;
    }

    #alarmbadge {
        display: inline-block;
        padding-top: 50%;
        padding-bottom: 50%;
        margin-left: 4px;
        margin-right: 4px;
    }

    #alarmmenu {
        list-style: none;
        width: 380px;
        /*font-family: KardexMOT-Light;*/
    }

    #alarmmenuheader {
        padding: 0 0 10px 10px;
        border-bottom: 1px solid #5b636c;
    }

    #alarmmenu h4 {
        color: #444444;
    }

    #alarmmenu h4 small {
        color: #999999;
        font-size: 10px;
        position: absolute;
        right: 2px;
    }

    #alarmmenulist {
        display: flex;
        max-height: 50vh;
        overflow-y: auto;
        position: relative;
        flex-wrap: wrap;
        list-style: none;
        border-bottom: 1px solid #5b636c;
    }

    #alarmmenulist > div {
        cursor: pointer;
        display: flex;
        align-items: center;
        padding: 5px;
        width: 100%;
        overflow: hidden;
    }

    #alarmmenulist > div > div:nth-child(2) {
        padding-left: 15px;
    }

    #alarmmenulist > div:hover {
        background: #e9e9e9;
    }

    #alarmmenu-show-all {
        padding-top: 10px;
        padding-bottom: 12px;
        margin-bottom: -12px;
        text-align: center;
    }

    #alarmmenu-show-all a {
        cursor: pointer;
        color: #337ab7;
    }

    #btn-login {
        cursor: pointer;
        margin: 0 0 0 40px;
        text-transform: lowercase;
        font-size: 16px;
    }

    #btn-userinfo {
        cursor: pointer;
        margin-left: 20px;
        text-transform: lowercase;
    }

    #btn-userinfo > div {
        display: flex;
        align-items: center;
    }

    #logonMenu {
        list-style: none;
        padding: 12px;
    }

    #logonMenu li:nth-child(4) {
        padding-top: 10px;
    }

    #userMenu div {
        display: flex;
        flex-direction: column;
        justify-content: center;
        align-items: center;
    }

    #userMenu .logoff {
        width: 100%;
    }

    #btnLogoff:hover {
        background: #e9e9e9;
    }

    #btn-header-search {
        margin-left: 20px;
        font-size: 12px;
    }

    #nav-header {
        grid-area: navheader;
        background-color: #21333D;
        display: flex;
        justify-content: center;
        align-items: center;
        overflow: hidden;
    }

    #nav-header img {
        min-width: 260px;
    }

    .mlog-nav {
        grid-area: nav;
        font-family: KardexMOT-Light, sans-serif;
        background: url(/assets/images/M.svg) no-repeat #21333d;
        background-position: bottom;
        background-size: 280px;
        overflow-y: auto;
        overflow-x: hidden;
    }

    .mlog-nav::-webkit-scrollbar {
        display: none;
    }

    .mlog-nav ul {
        list-style: none;
    }

    .treeview-menu {
        display: none;
        overflow: hidden;
    }

    .treeview-menu li {
        padding: 5px 5px 5px 15px;
        display: block;
        font-size: 14px;
    }

    .sidebar-menu input[type=checkbox]:checked + label + ul {
        display: inline;
    }

    .sidebar-menu label > svg {
        transition: transform .65s ease;
    }

    .sidebar-menu input[type=checkbox]:checked + label > svg {
        transform: rotate(90deg);
    }

    .sidebar-menu li {
        color: #ffffff;
    }

    .sidebar-menu li a i {
        margin-right: 5px;
    }

    .sidebar-menu li a svg {
        margin-right: 5px;
    }

    .sidebar-menu a {
        color: white;
    }

    .sidebar-menu > li > label {
        height: 36px;
        width: 100%;
        display: flex;
        position: relative;
        align-items: center;
        padding-bottom: 4px;
            font-weight: 700;
        font-size: 24px;
    }

    .sidebar-menu > li > a {
        margin-left: 50px;
        align-items: center;
        padding-bottom: 4px;
        font-weight: 700;
        font-size: 24px;
    }

    .sidebar-menu > li > input[type=checkbox] + label {
        padding-left: 50px;
        font-size: 24px;
        cursor: pointer;
    }

    .sidebar-menu > li > input[type=checkbox]:checked + label {
        border-left: 3px solid var(--kx-bg);
        padding-left: 47px;
        background: #182A33;
    }

    .sidebar-menu > li > input[type=checkbox]:checked + label + ul > li {
        background: #182A33;
    }

    .sidebar-menu li a t-t:hover, .treeview > label:hover {
        color: #96AEC2;
    }

    .treeview-menu > li > label {
        height: 16px;
        width: 100%;
        display: flex;
        position: relative;
        align-items: center;
        padding-bottom: 4px;
        cursor: pointer;
    }

    .sidebar-menu > .treeview {
        border-bottom: 1px solid #5b636c;
    }

    .sidebar-menu > .treeview > label {
        margin-bottom: 0;
    }

    .treeview .fa-caret-right {
        color: #96AEC2;
        position: absolute;
        right: 40px;
    }

    .sidebar-menu > li:nth-child(1) {
        margin-top: 20px;
        border-top: 1px solid #5b636c;
    }
    content {
        grid-area: content;
    }

    hr {
        margin-top: 0;
        margin-bottom: 0;
        border-top: 1px solid #eee;
    }

    .context-menu-selected {
        padding: 0 4px; 
    }

    .context-menu-selected:hover {
        background: #e9e9e9;
    }

    /* fix for bootstrap dialog*/
    .bootstrap-dialog-header {
        width: 100%;
    }

    .bootstrap-dialog.type-primary .modal-header {
        background-color: var(--kx-info);
    }

    .bootstrap-dialog.type-success .modal-header {
        background-color: var(--kx-success);
    }

    .bootstrap-dialog.type-warning .modal-header {
        background-color: var(--kx-warning);
    }

    .bootstrap-dialog.type-danger .modal-header {
        background-color: var(--kx-error);
    }

    .bootstrap-dialog .bootstrap-dialog-title {
        color: var(--kx-text);
    }

    .bootstrap-dialog.type-danger .bootstrap-dialog-title {
        color: var(--kx-text-light);
    }

    .green-test .ag-theme-alpine .ag-row-selected {
        background-color: rgba(40, 167, 69, 0.3);
    }

    .notification-area {
        pointer-events: none;
        background: transparent;
        position: absolute;
        top: 50px;
        right: 0;
        width: 300px;
        height: 100%;
        display: flex;
        flex-direction: column;
        z-index: 1;
    }

    .notification-area > div {
        display: block;
        z-index: 1;
        background-color:rgba(217, 237, 247, 0.9);
        border: 1px solid rgb(188, 232, 241);
        margin: 4px;
        padding: 10px;
        white-space: normal;
        color: rgb(58, 135, 173);
        font-weight: 700;
        border-radius: 5px;
        pointer-events: auto;
        transform: scaleY(0);
        animation: fade 5s;
        overflow: hidden;
    }

    @keyframes fade {
        0% { transform: scaleY(0); }
        20% { transform: scaleY(1); }
        80% { transform: scaleY(1); }
        100% { transform: scaleY(0); }
    }

Additional

[FlorianRappl]

Can you trim the CSS to the relevant part? Thanks!

[FlorianRappl]

Available in devel / preview version (upcoming 0.16.2).

[jogibear9988]

@FlorianRappl please wait with the final release. The error is gone, but something on my page is now messed up. I'll look for it...

[jogibear9988]

so I've found something.

if I look at the original css:

#nav-header {
    grid-area: navheader;
    background-color: #21333D;
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden;
}

after parsing and minimize:

#nav-header {
    grid-area: navheader / navheader / auto / auto;
    background-color: rgba(33, 51, 61, 1);
    display: flex;
    justify-content: center;
    align-items: center;
    overflow: hidden
}

this has a different effect the

 grid-area: navheader / navheader / auto / auto;

is rendered differently in chrome as

 grid-area: navheader;

[jogibear9988]

and another one....

* {
    margin: 0;
    padding: 0;
    box-sizing: border-box;
    word-wrap: normal;
    flex-wrap:  nowrap;
    white-space:  nowrap;
}

you completely remove the "box-sizing"

[FlorianRappl]

Feel free to contribute via a pull request. Much appreciated!

[jogibear9988]

@FlorianRappl why did you close? is it intended from you to convert grid area syntax?

[FlorianRappl]

Different issue (see title and description from you).

You can open new issues, but then again - feel free to contribute via pull requests.