github_branch_default: send only fields that changed. Fixes #625 #620. (#666)

* github_branch_default: send only fields that changed. Fixes #625 #620.

* fix failing test and update docs

Co-authored-by: Jeremy Udit <[email protected]>

Author: dee-kryvenko

github/resource_github_branch_default.go

@@ -4,6 +4,7 @@ import (
 	"context"
 	"log"
 
+	"github.com/google/go-github/v32/github"
 	"github.com/hashicorp/terraform-plugin-sdk/helper/schema"
 )
 
@@ -38,14 +39,11 @@ func resourceGithubBranchDefaultCreate(d *schema.ResourceData, meta interface{})
 	repoName := d.Get("repository").(string)
 	defaultBranch := d.Get("branch").(string)
 
-	ctx := context.Background()
-
-	repository, _, err := client.Repositories.Get(ctx, owner, repoName)
-	if err != nil {
-		return err
+	repository := &github.Repository{
+		DefaultBranch: &defaultBranch,
 	}
 
-	repository.DefaultBranch = &defaultBranch
+	ctx := context.Background()
 
 	log.Printf("[DEBUG] Creating branch default: %s (%s/%s)", defaultBranch, owner, repoName)
 	if _, _, err := client.Repositories.Edit(ctx, owner, repoName, repository); err != nil {
@@ -87,17 +85,14 @@ func resourceGithubBranchDefaultDelete(d *schema.ResourceData, meta interface{})
 	repoName := d.Id()
 	defaultBranch := d.Get("branch").(string)
 
-	ctx := context.Background()
-
-	repository, _, err := client.Repositories.Get(ctx, owner, repoName)
-	if err != nil {
-		return err
+	repository := &github.Repository{
+		DefaultBranch: nil,
 	}
 
-	repository.DefaultBranch = nil
+	ctx := context.Background()
 
 	log.Printf("[DEBUG] Removing branch default: %s (%s/%s)", defaultBranch, owner, repoName)
-	_, _, err = client.Repositories.Edit(ctx, owner, repoName, repository)
+	_, _, err := client.Repositories.Edit(ctx, owner, repoName, repository)
 	return err
 }
 
@@ -108,14 +103,11 @@ func resourceGithubBranchDefaultUpdate(d *schema.ResourceData, meta interface{})
 	repoName := d.Id()
 	defaultBranch := d.Get("branch").(string)
 
-	ctx := context.Background()
-
-	repository, _, err := client.Repositories.Get(ctx, owner, repoName)
-	if err != nil {
-		return err
+	repository := &github.Repository{
+		DefaultBranch: &defaultBranch,
 	}
 
-	repository.DefaultBranch = &defaultBranch
+	ctx := context.Background()
 
 	log.Printf("[DEBUG] Updating branch default: %s (%s/%s)", defaultBranch, owner, repoName)
 	if _, _, err := client.Repositories.Edit(ctx, owner, repoName, repository); err != nil {

github/resource_github_branch_default_test.go

@@ -65,30 +65,30 @@ func TestAccGithubBranchDefault(t *testing.T) {
 
 	})
 
-	t.Run("can be configured to override the default_branch of the repository", func(t *testing.T) {
+	t.Run("replaces the default_branch of a repository", func(t *testing.T) {
 
 		config := fmt.Sprintf(`
 			resource "github_repository" "test" {
 				name      = "tf-acc-test-%s"
-				default_branch = "main"
 				auto_init = true
 			}
-
-			resource "github_branch_default" "test" {
-				repository     = github_repository.test.name
-				branch         = "override"
+			
+			resource "github_branch" "test" {
+				repository = github_repository.test.name
+				branch     = "test"
+			}
+			  
+			resource "github_branch_default" "test"{
+				repository = github_repository.test.name
+				branch     = github_branch.test.branch
 			}
 
 		`, randomID)
 
 		check := resource.ComposeTestCheckFunc(
 			resource.TestCheckResourceAttr(
 				"github_branch_default.test", "branch",
-				"override",
-			),
-			resource.TestCheckResourceAttr(
-				"github_branch_default.test", "repository",
-				fmt.Sprintf("tf-acc-test-%s", randomID),
+				"test",
 			),
 		)
 

website/docs/r/branch_default.html.markdown

@@ -11,19 +11,15 @@ Provides a GitHub branch default resource.
 
 This resource allows you to set the default branch for a given repository. 
 
+Note that use of this resource is incompatible with the `default_branch` option of the `github_repository` resource.  Using both will result in plans always showing a diff.
+
 ## Example Usage
 
 ```hcl
 resource "github_repository" "example" {
   name        = "example"
   description = "My awesome codebase"
-
-  visibility = "private"
-
-  template {
-    owner = "github"
-    repository = "terraform-module-template"
-  }
+  auto_init   = true
 }
 
 resource "github_branch" "development" {