This is a simple library for replacing jquery validation as the client side validation library, with VeeValidate.

To use VeeValidate in place of JQuery validation, use the AddVeeValidation() extension in the ConfigureServices method of your startup.cs file.

public void ConfigureServices(IServiceCollection services)
{
    services.AddVeeValidation();
    services.AddMvc();
}

Reference Vue JS, VeeValidate, and a polyfill for promises if you plan on supporting older browsers:

<script src="https://cdnjs.cloudflare.com/ajax/libs/vue/2.5.16/vue.js" integrity="sha256-CMMTrj5gGwOAXBeFi7kNokqowkzbeL8ydAJy39ewjkQ=" crossorigin="anonymous"></script>
<script src="https://cdnjs.cloudflare.com/ajax/libs/vee-validate/2.0.9/vee-validate.js" integrity="sha256-t+DWUFe1/1QjOFx+LxCzWqka3Vq1ZBGJJvnNSq5XHVU=" crossorigin="anonymous"></script>
<script asp-fallback-test="window.Promise"
        asp-fallback-src="https://cdnjs.cloudflare.com/ajax/libs/es6-promise/4.1.1/es6-promise.auto.js">
</script>

Setup VeeValidate:

<script>
    Vue.use(VeeValidate);     
</script>

The table below shows the VeeValidate rules generated for each of the .NET validation attributes:

NOTE: VeeValidate does not have a rule for phone numbers so there is no client validation implemented for this yet.

To use VeeValidate in place of JQuery validation, use the UseVeeValidate() extension on the FluentValidationMvcConfiguration class in the ConfigureServices method of your startup.cs file.
Example:

public void ConfigureServices(IServiceCollection services)
{
    services.AddVeeValidation();
    services.AddMvc()
            .AddFluentValidation(config =>
            {
                config.RegisterValidatorsFromAssembly(typeof(Startup).Assembly);
                config.ConfigureClientsideValidation(options =>
                    options.UseVeeValidate()
                );
            });
}

The date formatter needs to be passed into both extensions when specified.
Example:

public void ConfigureServices(IServiceCollection services)
{
    string DateFormatProvider(HttpContext ctx) => "dd/MM/yyyy";

    services.AddVeeValidation(options =>
    {        
        options.DateFormatProvider = DateFormatProvider;
    });
    services.AddMvc()
        .AddFluentValidation(config =>
        {
            config.RegisterValidatorsFromAssembly(typeof(Startup).Assembly);
            config.ConfigureClientsideValidation(options =>
                options.UseVeeValidate(DateFormatProvider)
            );
        });

}

The table below shows the VeeValidate rules generated for each of the FluentValidation rules:

Any rules specified in HTML will take priority over the generated rules. Rules need to be declared in object format if there are any generated rules for the field.
Example:

<input asp-for="RequiredField" v-validate="{required:isRequired}" />

By default, the asp-message-for and asp-validation-summary tag helpers will be overridden to only show VeeValidate errors. This can be disabled by setting the OverrideValidationTagHelpers option to false.
Example:

public void ConfigureServices(IServiceCollection services)
{
    services.AddVeeValidation(options =>
    {        
        options.OverrideValidationTagHelpers = false; 
    });
    services.AddMvc();
}

Caveat: The asp-validation-summary with "ModelOnly" (and OverrideValidationTagHelpers is true) will not work correctly out of the box. To get this working you can include the VeeValidateSnippets.ValidationSummaryMixin (after vee-validate.js reference).
Example:

@inject VeeValidateSnippets VeeValidateSnippets
@Html.Raw(VeeValidateSnippets.ValidationSummaryMixin)
<div asp-validation-summary="ModelOnly"></div>

Vue JS - https://vuejs.org/
VeeValidate - http://vee-validate.logaretm.com/v2/