## Why is this an issue?

Hard-coding a URI makes it difficult to test a program for a variety of reasons:

- path literals are not always portable across operating systems
- a given absolute path may not exist in a specific test environment
- a specified Internet URL may not be available when executing the tests
- production environment filesystems usually differ from the development environment

In addition, hard-coded URIs can contain sensitive information, like IP addresses, and they should not be stored in the code.

For all those reasons, a URI should never be hard coded. Instead, it should be replaced by a customizable parameter.

Further, even if the elements of a URI are obtained dynamically, portability can still be limited if the path delimiters are hard-coded.

This rule raises an issue when URIs or path delimiters are hard-coded.

### Exceptions

This rule does not raise an issue when an ASP.NET virtual path is passed as an argument to one of the following:

- methods: `System.Web.HttpServerUtilityBase.MapPath()`, `System.Web.HttpRequestBase.MapPath()`, `System.Web.HttpResponseBase.ApplyAppPathModifier()`, `System.Web.Mvc.UrlHelper.Content()`
- all methods of: `System.Web.VirtualPathUtility`
- constructors of: `Microsoft.AspNetCore.Mvc.VirtualFileResult`, `Microsoft.AspNetCore.Routing.VirtualPathData`

## How to fix it

### Code examples

#### Noncompliant code example

    public class Foo {
      public List<User> ListUsers() {
        string userListPath = "/home/mylogin/Dev/users.txt"; // Noncompliant
        return ParseUsers(userListPath);
      }
    }

#### Compliant solution

    public class Foo {
      // Configuration is a class that returns customizable properties: it can be mocked to be injected during tests.
      private Configuration config;
      public Foo(Configuration myConfig) {
        this.config = myConfig;
      }
      public List<User> ListUsers() {
        // Find here the way to get the correct folder, in this case using the Configuration object
        string listingFolder = config.GetProperty("myApplication.listingFolder");
        // and use this parameter instead of the hard coded path
        string userListPath = Path.Combine(listingFolder, "users.txt"); // Compliant
        return ParseUsers(userListPath);
      }
    }