Improve git test (#7086)

* Ensure that the lfs files are created with a different prefix
* Reduce the replication in git_test.go

integrations/api_helper_for_declarative_test.go

@@ -5,11 +5,14 @@
 package integrations
 
 import (
+	"encoding/json"
 	"fmt"
 	"io/ioutil"
 	"net/http"
 	"testing"
 
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/auth"
 	api "code.gitea.io/gitea/modules/structs"
 	"github.com/stretchr/testify/assert"
 )
@@ -150,3 +153,42 @@ func doAPICreateDeployKey(ctx APITestContext, keyname, keyFile string, readOnly
 		ctx.Session.MakeRequest(t, req, http.StatusCreated)
 	}
 }
+
+func doAPICreatePullRequest(ctx APITestContext, owner, repo, baseBranch, headBranch string) func(*testing.T) (api.PullRequest, error) {
+	return func(t *testing.T) (api.PullRequest, error) {
+		urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/pulls?token=%s",
+			owner, repo, ctx.Token)
+		req := NewRequestWithJSON(t, http.MethodPost, urlStr, &api.CreatePullRequestOption{
+			Head:  headBranch,
+			Base:  baseBranch,
+			Title: fmt.Sprintf("create a pr from %s to %s", headBranch, baseBranch),
+		})
+
+		expected := 201
+		if ctx.ExpectedCode != 0 {
+			expected = ctx.ExpectedCode
+		}
+		resp := ctx.Session.MakeRequest(t, req, expected)
+		decoder := json.NewDecoder(resp.Body)
+		pr := api.PullRequest{}
+		err := decoder.Decode(&pr)
+		return pr, err
+	}
+}
+
+func doAPIMergePullRequest(ctx APITestContext, owner, repo string, index int64) func(*testing.T) {
+	return func(t *testing.T) {
+		urlStr := fmt.Sprintf("/api/v1/repos/%s/%s/pulls/%d/merge?token=%s",
+			owner, repo, index, ctx.Token)
+		req := NewRequestWithJSON(t, http.MethodPost, urlStr, &auth.MergePullRequestForm{
+			MergeMessageField: "doAPIMergePullRequest Merge",
+			Do:                string(models.MergeStyleMerge),
+		})
+
+		if ctx.ExpectedCode != 0 {
+			ctx.Session.MakeRequest(t, req, ctx.ExpectedCode)
+			return
+		}
+		ctx.Session.MakeRequest(t, req, 200)
+	}
+}