campaigns: restore pre-3.20 instance compatibility

CHANGELOG.md

@@ -17,6 +17,8 @@ All notable changes to `src-cli` are documented in this file.
 
 ### Fixed
 
+- Restored backward compatibility when creating campaigns against Sourcegraph 3.19, provided author details are not provided in the campaign spec. [#370](https://github.com/sourcegraph/src-cli/pull/370)
+
 ### Removed
 
 ## 3.21.6

internal/campaigns/changeset_spec.go

@@ -28,6 +28,6 @@ type CreatedChangeset struct {
 type GitCommitDescription struct {
 	Message     string `json:"message"`
 	Diff        string `json:"diff"`
-	AuthorName  string `json:"authorName"`
-	AuthorEmail string `json:"authorEmail"`
+	AuthorName  string `json:"authorName,omitempty"`
+	AuthorEmail string `json:"authorEmail,omitempty"`
 }

internal/campaigns/executor.go

@@ -85,12 +85,13 @@ func (ts *TaskStatus) IsCompleted() bool {
 type executor struct {
 	ExecutorOpts
 
-	cache   ExecutionCache
-	client  api.Client
-	logger  *LogManager
-	creator *WorkspaceCreator
-	tasks   sync.Map
-	tempDir string
+	cache    ExecutionCache
+	client   api.Client
+	features featureFlags
+	logger   *LogManager
+	creator  *WorkspaceCreator
+	tasks    sync.Map
+	tempDir  string
 
 	par           *parallel.Run
 	doneEnqueuing chan struct{}
@@ -99,12 +100,13 @@ type executor struct {
 	specsMu sync.Mutex
 }
 
-func newExecutor(opts ExecutorOpts, client api.Client) *executor {
+func newExecutor(opts ExecutorOpts, client api.Client, features featureFlags) *executor {
 	return &executor{
 		ExecutorOpts:  opts,
 		cache:         opts.Cache,
 		creator:       opts.Creator,
 		client:        client,
+		features:      features,
 		doneEnqueuing: make(chan struct{}),
 		logger:        NewLogManager(opts.TempDir, opts.KeepLogs),
 		tempDir:       opts.TempDir,
@@ -208,7 +210,7 @@ func (x *executor) do(ctx context.Context, task *Task) (err error) {
 				diff = result.Commits[0].Diff
 			}
 
-			spec := createChangesetSpec(task, diff)
+			spec := createChangesetSpec(task, diff, x.features)
 
 			status.Cached = true
 			status.ChangesetSpec = spec
@@ -267,7 +269,7 @@ func (x *executor) do(ctx context.Context, task *Task) (err error) {
 	}
 
 	// Build the changeset spec.
-	spec := createChangesetSpec(task, string(diff))
+	spec := createChangesetSpec(task, string(diff), x.features)
 
 	status.ChangesetSpec = spec
 	x.updateTaskStatus(task, status)
@@ -305,16 +307,18 @@ func reachedTimeout(cmdCtx context.Context, err error) bool {
 	return errors.Is(err, context.DeadlineExceeded)
 }
 
-func createChangesetSpec(task *Task, diff string) *ChangesetSpec {
+func createChangesetSpec(task *Task, diff string, features featureFlags) *ChangesetSpec {
 	repo := task.Repository.Name
 
 	var authorName string
 	var authorEmail string
 
 	if task.Template.Commit.Author == nil {
-		// user did not provide author info, so use defaults
-		authorName = "Sourcegraph"
-		authorEmail = "campaigns@sourcegraph.com"
+		if features.includeAutoAuthorDetails {
+			// user did not provide author info, so use defaults
+			authorName = "Sourcegraph"
+			authorEmail = "campaigns@sourcegraph.com"
+		}
 	} else {
 		authorName = task.Template.Commit.Author.Name
 		authorEmail = task.Template.Commit.Author.Email

internal/campaigns/executor_test.go

@@ -144,7 +144,7 @@ func TestExecutor_Integration(t *testing.T) {
 				opts.Timeout = 5 * time.Second
 			}
 
-			executor := newExecutor(opts, client)
+			executor := newExecutor(opts, client, featuresAllEnabled())
 
 			template := &ChangesetTemplate{}
 			for _, r := range tc.repos {

internal/campaigns/features.go

@@ -0,0 +1,32 @@
+package campaigns
+
+import (
+	"github.com/pkg/errors"
+	"github.com/sourcegraph/src-cli/internal/api"
+)
+
+// featureFlags represent features that are only available on certain
+// Sourcegraph versions and we therefore have to detect at runtime.
+type featureFlags struct {
+	includeAutoAuthorDetails bool
+	useGzipCompression       bool
+}
+
+func (ff *featureFlags) setFromVersion(version string) error {
+	for _, feature := range []struct {
+		flag       *bool
+		constraint string
+		minDate    string
+	}{
+		{&ff.includeAutoAuthorDetails, ">= 3.20.0", "2020-09-10"},
+		{&ff.useGzipCompression, ">= 3.21.0", "2020-10-12"},
+	} {
+		value, err := api.CheckSourcegraphVersion(version, feature.constraint, feature.minDate)
+		if err != nil {
+			return errors.Wrap(err, "failed to check version returned by Sourcegraph")
+		}
+		*feature.flag = value
+	}
+
+	return nil
+}

internal/campaigns/features_test.go

@@ -0,0 +1,8 @@
+package campaigns
+
+func featuresAllEnabled() featureFlags {
+	return featureFlags{
+		includeAutoAuthorDetails: true,
+		useGzipCompression:       true,
+	}
+}

internal/campaigns/service.go

@@ -17,9 +17,9 @@ import (
 )
 
 type Service struct {
-	allowUnsupported   bool
-	client             api.Client
-	useGzipCompression bool
+	allowUnsupported bool
+	client           api.Client
+	features         featureFlags
 }
 
 type ServiceOpts struct {
@@ -71,17 +71,11 @@ func (svc *Service) DetermineFeatureFlags(ctx context.Context) error {
 		return errors.Wrap(err, "failed to query Sourcegraph version to check for available features")
 	}
 
-	supportsGzip, err := api.CheckSourcegraphVersion(version, ">= 3.21.0", "2020-10-12")
-	if err != nil {
-		return errors.Wrap(err, "failed to check version returned by Sourcegraph")
-	}
-	svc.useGzipCompression = supportsGzip
-
-	return nil
+	return svc.features.setFromVersion(version)
 }
 
 func (svc *Service) newRequest(query string, vars map[string]interface{}) api.Request {
-	if svc.useGzipCompression {
+	if svc.features.useGzipCompression {
 		return svc.client.NewGzippedRequest(query, vars)
 	}
 	return svc.client.NewRequest(query, vars)
@@ -201,7 +195,7 @@ type ExecutorOpts struct {
 }
 
 func (svc *Service) NewExecutor(opts ExecutorOpts) Executor {
-	return newExecutor(opts, svc.client)
+	return newExecutor(opts, svc.client, svc.features)
 }
 
 func (svc *Service) NewWorkspaceCreator(dir string, cleanArchives bool) *WorkspaceCreator {