One of the trickiest cases to write previews

ListItemPreview.kt

internal class ListItemAllRoundedSurfaceContentProvider :
    PreviewParameterProvider<ListItemPreviewViewState> {
    override val values: Sequence<ListItemPreviewViewState> =
        listItemContentProviderValues(AllRounded)
}

internal class ListItemTopRoundedSurfaceContentProvider :
    PreviewParameterProvider<ListItemPreviewViewState> {
    override val values: Sequence<ListItemPreviewViewState> =
        listItemContentProviderValues(TopRounded)
}

internal class ListItemBottomRoundedSurfaceContentProvider :
    PreviewParameterProvider<ListItemPreviewViewState> {
    override val values: Sequence<ListItemPreviewViewState> =
        listItemContentProviderValues(BottomRounded)
}

internal class ListItemSharpSurfaceContentProvider :
    PreviewParameterProvider<ListItemPreviewViewState> {
    override val values: Sequence<ListItemPreviewViewState> =
        listItemContentProviderValues(Sharp)
}

internal class ListItemNoneSurfaceContentProvider :
    PreviewParameterProvider<ListItemPreviewViewState> {
    override val values: Sequence<ListItemPreviewViewState> =
        listItemContentProviderValues(None)
}

internal class ListItemWrappedSurfaceContentProvider :
    PreviewParameterProvider<ListItemPreviewViewState> {
    override val values: Sequence<ListItemPreviewViewState> =
        listItemContentProviderValues(Wrapped)
}

private fun listItemContentProviderValues(
    surface: ListItemSurfaceShape,
) = buildList {
    primaryTextValues().forEach { primaryText ->
        secondaryTextValues().forEach { secondaryText ->
            trailingTextValues().forEach { trailingText ->
                startIconValues().forEach { startIcon ->
                    badgeValues().forEach { badge ->
                        endIconResIdValues().forEach { endIconResId ->
                            add(
                                ListItemPreviewViewState(
                                    badge = badge,
                                    primaryText = primaryText,
                                    modifier = Modifier.fillMaxWidth(),
                                    secondaryText = secondaryText,
                                    trailingText = trailingText,
                                    startIcon = startIcon,
                                    endIconResId = endIconResId,
                                    onClick = { },
                                    onEndIconClick = { },
                                    surface = surface,
                                ),
                            )
                        }
                    }
                }
            }
        }
    }
}.asSequence()

internal data class ListItemPreviewViewState(
    val badge: ListItemIndicatorBadge?,
    val primaryText: String,
    val startIcon: ListItemStartIcon?,
    val endIconColor: ListItemIconColor = NeutralMinorMuted,
    val modifier: Modifier = Modifier,
    val secondaryText: String? = null,
    val trailingText: String? = null,
    val trailingTextColor: ListItemTrailingTextStyle = OnSurfaceOrBackgroundMuted,
    @DrawableRes val endIconResId: Int? = null,
    val onClick: OnClick? = null,
    val onEndIconClick: OnClick? = null,
    val surface: ListItemSurfaceShape = None,
)

private fun primaryTextValues() =
    listOf("Primary Text")

private fun secondaryTextValues() =
    listOf(null, "Secondary Text")

private fun trailingTextValues() =
    listOf(null, "Trailing Text")

private fun startIconValues(): List<ListItemStartIcon?> =
    listOf(
        null,
        ListItemStartIcon(
            resId = IconsR.ic_account,
            style = ListItemStartIconStyle.Normal,
            color = Primary,
        ),
        ListItemStartIcon(
            resId = IconsR.ic_account,
            style = ListItemStartIconStyle.Wrapped,
            color = Primary,
        ),
    )

private fun badgeValues() =
    listOf(
        null,
        ListItemIndicatorDot,
        ListItemIndicatorCounter(38),
    )

private fun endIconResIdValues() =
    listOf(null, IconsR.ic_chevron_right_sm)

@Composable
internal fun ListItemPreview(
    state: ListItemPreviewViewState,
) {
    ListItem(
        indicatorBadge = state.badge,
        primaryText = state.primaryText,
        startIcon = state.startIcon,
        modifier = Modifier.fillMaxWidth(),
        endIconColor = state.endIconColor,
        secondaryText = state.secondaryText,
        trailingText = state.trailingText,
        trailingTextStyle = state.trailingTextColor,
        endIconResId = state.endIconResId,
        onClick = state.onClick,
        onEndIconClick = state.onEndIconClick,
        surface = state.surface,
    )
}

@Composable
internal fun ListItemPreviewWithWrapper(
    viewState: ListItemPreviewViewState,
) {
    CuvvaTheme {
        DesignComponentGenericPreviewWrapper {
            ListItemPreview(viewState)
        }
    }
}

Related to https://gist.github.com/Sottti/d9933f0d7919b1c9996a2e76b7408019