Extend -SkipHeaderValidation to include -UserAgent to support non-standard User-Agent headers

[markekraus]

Synopsis

Extends #4085 to include the -UserAgent parameter supplied User-Agent header.

Description

Some API's, such as Reddit require special User-Agent headers to identify application consumers of the API. Currently, Invoke-WebRequest and Invoke-RestMethod are unable to properly use non-compliant User-Agent headers. This extends the behavior of the -SkipHeaderValidation switch parameter to include the User-Agent header supplied by the -UserAgent parameter.

Test Code

$Uri='http://httpbin.org/headers'Invoke-WebRequest-Uri $Uri-UserAgent 'Invalid:Agent'-SkipHeaderValidation Invoke-RestMethod-Uri $Uri-UserAgent 'Invalid:Agent'-SkipHeaderValidation

Current Behavior:

Invoke-WebRequest : The format of value 'Invalid:Agent' is invalid. At line:2 char:1 + Invoke-WebRequest -Uri $Uri -UserAgent 'Invalid:Agent' + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [Invoke-WebRequest], FormatException + FullyQualifiedErrorId : System.FormatException,Microsoft.PowerShell.Commands.InvokeWebRequestCommand Invoke-RestMethod : The format of value 'Invalid:Agent' is invalid. At line:3 char:1 + Invoke-RestMethod -Uri $Uri -UserAgent 'Invalid:Agent' + ~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ + CategoryInfo : NotSpecified: (:) [Invoke-RestMethod], FormatException + FullyQualifiedErrorId : System.FormatException,Microsoft.PowerShell.Commands.InvokeRestMethodCommand 

New Behavior

 StatusCode : 200 StatusDescription : OK Content :{"headers":{"Connection": "close", "Host": "httpbin.org", "User-Agent": "Invalid:Agent" } } RawContent : HTTP/1.1 200 OK Connection: keep-alive Date: Thu, 03 Aug 2017 10:25:25 GMT Via: 1.1 vegur Server: meinheld/0.6.1 Access-Control-Allow-Origin: * Access-Control-Allow-Credentials: true X-Powered-... Forms : Headers :{[Connection, System.String[]], [Date, System.String[]], [Via, System.String[]], [Server, System.String[]]...} Images :{} InputFields :{} Links :{} ParsedHtml : RawContentLength : 113 RelationLink :{} headers : @{Connection=close; Host=httpbin.org; User-Agent=Invalid:Agent} 

[msftclas]

@markekraus,
Thanks for having already signed the Contribution License Agreement. Your agreement was validated by Microsoft. We will now review your pull request.
Thanks,
Microsoft Pull Request Bot

[SteveL-MSFT]

Thanks for the contribution, just one requested change

[SteveL-MSFT]

Instead of duplicating all the parameters, you should use splatting:

$args = @{Uri=$uri;Timeout=5;UserAgent=$useragent;...} Invoke-WebRequest @args Invoke-RestMethod @args 

[markekraus]

Used $Params instead of $args to avoid conflicts with the automatic variable.

[SteveL-MSFT]

LGTM