SwaggerUI causes Index.html startup side effect on IIS express in Blazor App

Question

I created a new Blazor Server project and added SwaggerUI and now the application searches for index.html as the start up object when I debug.

Interesting, I isolated the offending code to the routeprefix=""

app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("/swagger/v1/swagger.json", "v1.3");
    c.DocExpansion(DocExpansion.None);
   // c.RoutePrefix = "";
});

I run it once with the routeprefix ="" and the startup is set to index.html. Even when I comment it out, it still searches for the index.html page.

I did a few test and found that no relevant code was changed from the working and the non working.

I deployed the code to IIS and it seemed to work so I am guessing it maybe something to do with IIS express. I checked the configurations but did not find any think useful.

The code is the standard weather forecast test project created by default.

Here is the main program.

using BlazorAppIndexTest.Data;
using Microsoft.AspNetCore.Components;
using Microsoft.AspNetCore.Components.Web;
using Microsoft.OpenApi.Models;
using Swashbuckle.AspNetCore.SwaggerUI;

var builder = WebApplication.CreateBuilder(args);

// Add services to the container.
builder.Services.AddRazorPages();
builder.Services.AddServerSideBlazor();
builder.Services.AddControllers();
builder.Services.AddSingleton<WeatherForecastService>();
//first line added
builder.Services.AddSwaggerGen(c => { c.SwaggerDoc("v1", new OpenApiInfo { Title = "My Service", Version = "v1" }); });
var app = builder.Build();

// Configure the HTTP request pipeline.
if (!app.Environment.IsDevelopment())
{
    app.UseExceptionHandler("/Error");
    // The default HSTS value is 30 days. You may want to change this for production scenarios, see https://aka.ms/aspnetcore-hsts.
    app.UseHsts();
}

app.UseHttpsRedirection();

app.UseStaticFiles();


app.UseRouting();

app.MapBlazorHub();
app.MapFallbackToPage("/_Host");

//second line added
app.UseSwagger();
//third line added
app.UseSwaggerUI(c =>
{
    c.SwaggerEndpoint("/swagger/v1/swagger.json", "v1.3");
    c.DocExpansion(DocExpansion.None);
   // c.RoutePrefix = "";
});


app.Run();

Anyone have any ideas of how to fix this or force the application to start with razor page.

Answer 1

AS usual, I found the answer after I posted the question.

Clearing the browser cache worked. I swear I tried that before.