Fix to support creating MRs for repositories cloned with SSH alias (#5082)

### PR Description

Use case: some repositories are cloned with a full SSH alias (without a
user). E.g. in `.ssh/config` you have

```
Host gitlab
    HostName gitlab.com
    User git
    IdentityFile ...
```

and then you clone with `git clone gitlab:foo/bar`

According to the docs, you can add a service to `config.yaml` and it
should work:

```yaml
services:
  gitlab: 'gitlab:gitlab.com'
```

But currently it doesn't because lazygit expects all remote URLs to have
a user. This can be fixed by the user by changing the URL to e.g.
`git@gitlab:foo/bar`, but it breaks the user flow and is quite
unexpected.

This PR changes `defaultUrlRegexStrings` and makes the `user@` part of
the remote URL optional. Fixes the issue for Github and Gitlab which use
the default regexes.

Author: stefanhaller

pkg/commands/hosting_service/definitions.go

@@ -4,7 +4,7 @@ package hosting_service
 // at https://regex101.com using the flavor Golang
 var defaultUrlRegexStrings = []string{
 	`^(?:https?|ssh)://[^/]+/(?P<owner>.*)/(?P<repo>.*?)(?:\.git)?$`,
-	`^.*?@.*:/*(?P<owner>.*)/(?P<repo>.*?)(?:\.git)?$`,
+	`^(.*?@)?.*:/*(?P<owner>.*)/(?P<repo>.*?)(?:\.git)?$`,
 }
 var defaultRepoURLTemplate = "https://{{.webDomain}}/{{.owner}}/{{.repo}}"
 

pkg/commands/hosting_service/hosting_service_test.go

@@ -56,6 +56,16 @@ func TestGetPullRequestURL(t *testing.T) {
 				assert.Equal(t, "https://github.com/peter/calculator/compare/feature%2Fsum-operation?expand=1", url)
 			},
 		},
+		{
+			testName:             "Opens a link to new pull request on github custom SSH config alias and a corresponding service config",
+			from:                 "feature/sum-operation",
+			remoteUrl:            "github:peter/calculator.git",
+			configServiceDomains: map[string]string{"github": "github:github.com"},
+			test: func(url string, err error) {
+				assert.NoError(t, err)
+				assert.Equal(t, "https://github.com/peter/calculator/compare/feature%2Fsum-operation?expand=1", url)
+			},
+		},
 		{
 			testName:  "Opens a link to new pull request on github with extra slash removed",
 			from:      "feature/sum-operation",
@@ -133,6 +143,16 @@ func TestGetPullRequestURL(t *testing.T) {
 				assert.Equal(t, "https://gitlab.com/peter/calculator/-/merge_requests/new?merge_request%5Bsource_branch%5D=feature%2Fui", url)
 			},
 		},
+		{
+			testName:             "Opens a link to new pull request on gitlab with custom SSH config alias and a corresponding service config",
+			from:                 "feature/ui",
+			remoteUrl:            "gitlab:peter/calculator.git",
+			configServiceDomains: map[string]string{"gitlab": "gitlab:gitlab.com"},
+			test: func(url string, err error) {
+				assert.NoError(t, err)
+				assert.Equal(t, "https://gitlab.com/peter/calculator/-/merge_requests/new?merge_request%5Bsource_branch%5D=feature%2Fui", url)
+			},
+		},
 		{
 			testName:  "Opens a link to new pull request on gitlab with extra slash removed",
 			from:      "feature/ui",