Manual merge fallback (#230)

* Fallback to manual merge

* Log warning when using fallback manual merge

* Handle all merge ref errors

* Add propoer fetch params and fallback

* Force merge branch method

* Force PR merge branch method

* Fix unused var

* Mock pr head fetch error

* Use manual merge fallback with the pr head branch

* Add fallback manual merge with pr source branch

* Simplify fallback strategy creation

* Add logging

* Fix pr head branch based manual merge

* Remove head branch manual checkout fallback

* Remove mock errors

* Code cleanup

* Code cleanup

* Code cleanup

---------

Co-authored-by: Szabolcs Toth <[email protected]>

Author: godrei

gitclone/checkout.go

@@ -250,6 +250,25 @@ func createCheckoutStrategy(checkoutMethod CheckoutMethod, cfg Config, patchFile
 
 			return checkoutPRMergeRef{
 				params: *params,
+				fallbackCheckout: func(gitCmd git.Git) error {
+					log.Warnf("Using manual merge strategy with PR source branch")
+
+					manualMergeFallbackFetchOpts := selectFetchOptions(CheckoutPRManualMergeMethod, cfg.CloneDepth, cfg.FetchTags, cfg.UpdateSubmodules, len(cfg.SparseDirectories) != 0)
+					manualMergeFallbackFallback := selectFallbacks(CheckoutPRManualMergeMethod, manualMergeFallbackFetchOpts)
+
+					prRepositoryURL := ""
+					if isFork(cfg.RepositoryURL, cfg.PRSourceRepositoryURL) {
+						prRepositoryURL = cfg.PRSourceRepositoryURL
+					}
+
+					fallbackManualMergeWithSourceBranch, err := createManualMergeFallbackFunc(prRepositoryURL, cfg.Branch, cfg.Commit, cfg.PRDestBranch)
+					if err != nil {
+						return err
+					}
+
+					// PR merge branch checkout falls back to PR manual merge strategy using the PR source branch
+					return fallbackManualMergeWithSourceBranch.do(gitCmd, manualMergeFallbackFetchOpts, manualMergeFallbackFallback)
+				},
 			}, nil
 		}
 	case CheckoutPRDiffFileMethod:
@@ -429,3 +448,13 @@ func isPRCheckout(method CheckoutMethod) bool {
 		panic(fmt.Sprintf("implementation missing for enum value %T", method))
 	}
 }
+
+func createManualMergeFallbackFunc(repositoryURL, branch, commit, prDestBranch string) (*checkoutPRManualMerge, error) {
+	manualMergeFallbackParams, err := NewPRManualMergeParams(branch, commit, repositoryURL, prDestBranch)
+	if err != nil {
+		return nil, err
+	}
+	return &checkoutPRManualMerge{
+		params: *manualMergeFallbackParams,
+	}, nil
+}

gitclone/checkout_method_pr_auto_merge_branch.go

@@ -5,6 +5,7 @@ import (
 	"strings"
 
 	"github.com/bitrise-io/go-utils/command/git"
+	"github.com/bitrise-io/go-utils/log"
 )
 
 // PRMergeRefParams are parameters to check out a Merge/Pull Request's merge ref (the result of merging the 2 branches)
@@ -33,10 +34,25 @@ func NewPRMergeRefParams(mergeRef, headRef string) (*PRMergeRefParams, error) {
 }
 
 type checkoutPRMergeRef struct {
-	params PRMergeRefParams
+	params           PRMergeRefParams
+	fallbackCheckout fallbackCheckoutFunc
 }
 
+type fallbackCheckoutFunc func(gitCmd git.Git) error
+
 func (c checkoutPRMergeRef) do(gitCmd git.Git, fetchOpts fetchOptions, fallback fallbackRetry) error {
+	if err := c.performCheckout(gitCmd, fetchOpts, fallback); err != nil {
+		log.Warnf("Failed to checkout PR merge branch: %s", err)
+
+		if c.fallbackCheckout != nil {
+			return c.fallbackCheckout(gitCmd)
+		}
+		return err
+	}
+	return nil
+}
+
+func (c checkoutPRMergeRef) performCheckout(gitCmd git.Git, fetchOpts fetchOptions, fallback fallbackRetry) error {
 	// https://git-scm.com/book/en/v2/Git-Internals-The-Refspec
 	refSpec := fmt.Sprintf("%s:%s", c.remoteMergeRef(), c.localMergeRef())
 

gitclone/gitclone.go

@@ -138,7 +138,7 @@ func (g GitCloner) CheckoutState(cfg Config) (CheckoutStateResult, error) {
 	if !clean {
 		g.logger.Println()
 		g.logger.Warnf("Working tree is dirty, cleaning before checkout:")
-		
+
 		err = runner.Run(gitCmd.Clean("-fd"))
 		if err != nil {
 			g.logger.Warnf("Failed to clean untracked files: %s", err)

gitclone/gitclone_test.go

@@ -507,7 +507,8 @@ func Test_checkoutState(t *testing.T) {
 				assert.Nil(t, actualErr)
 			}
 
-			assert.Equal(t, tt.wantCmds, mockRunner.Cmds())
+			gotCmds := mockRunner.Cmds()
+			assert.Equal(t, tt.wantCmds, gotCmds)
 		})
 	}
 }