HtmlDocument's CssSelect fails when no html available #1212
Description
Apparently the <html> tag is optional on a webpage and so doesn't always exist. When it doesn't exist, HtmlDocument's CssSelect (and possible therefore, other functions) fail citing "No element html found".
For example, this works
#r @"..\packages\FSharp.Data.2.4.6\lib\net45\FSharp.Data.dll"
open FSharp.Data
open System.IO
open System.Text
HtmlDocument.Load(new MemoryStream(Encoding.UTF8.GetBytes(@"<html><body><h1 class='title'>Hi</h1></body></html>")))
|> (fun html -> html.CssSelect(".title"))
|> printfn "%A"
but this doesn't
#r @"..\packages\FSharp.Data.2.4.6\lib\net45\FSharp.Data.dll"
open FSharp.Data
open System.IO
open System.Text
HtmlDocument.Load(new MemoryStream(Encoding.UTF8.GetBytes(@"<body><h1 class='title'>Hi</h1></body>")))
|> (fun html -> html.CssSelect(".title"))
|> printfn "%A"
giving
System.Exception: No element html found!
at FSharp.Data.HtmlDocumentExtensions.Html(HtmlDocument doc) in C:\Git\FSharp.Data\src\Html\HtmlOperations.fs:line 858
at FSharp.Data.CssSelectorExtensions.CssSelectorExtensions.CssSelect(HtmlDocument doc, String selector) in C:\Git\FSharp.Data\src\Html\HtmlCssSelectors.fs:line 385
at <StartupCode$FSI_0006>.$FSI_0006.main@()
Stopped due to error