fix: GitHub Repository Update might fail when Pages enabled (#1716)

Co-authored-by: Keegan Campbell <[email protected]>

github/resource_github_repository.go

@@ -725,7 +725,16 @@ func resourceGithubRepositoryUpdate(d *schema.ResourceData, meta interface{}) er
 	if d.HasChange("pages") && !d.IsNewResource() {
 		opts := expandPagesUpdate(d.Get("pages").([]interface{}))
 		if opts != nil {
-			_, err := client.Repositories.UpdatePages(ctx, owner, repoName, opts)
+			pages, res, err := client.Repositories.GetPagesInfo(ctx, owner, repoName)
+			if res.StatusCode != http.StatusNotFound && err != nil {
+				return err
+			}
+
+			if pages == nil {
+				_, _, err = client.Repositories.EnablePages(ctx, owner, repoName, &github.Pages{Source: opts.Source, BuildType: opts.BuildType})
+			} else {
+				_, err = client.Repositories.UpdatePages(ctx, owner, repoName, opts)
+			}
 			if err != nil {
 				return err
 			}
@@ -827,17 +836,26 @@ func expandPages(input []interface{}) *github.Pages {
 		return nil
 	}
 	pages := input[0].(map[string]interface{})
-	pagesSource := pages["source"].([]interface{})[0].(map[string]interface{})
-	source := &github.PagesSource{
-		Branch: github.String(pagesSource["branch"].(string)),
-	}
-	if v, ok := pagesSource["path"].(string); ok {
-		// To set to the root directory "/", leave source.Path unset
-		if v != "" && v != "/" {
-			source.Path = github.String(v)
+	var source *github.PagesSource
+	if pagesSource, ok := pages["source"].([]interface{})[0].(map[string]interface{}); ok {
+		if v, ok := pagesSource["branch"].(string); ok {
+			if v != "" {
+				source.Branch = github.String(v)
+			}
+		}
+		if v, ok := pagesSource["path"].(string); ok {
+			// To set to the root directory "/", leave source.Path unset
+			if v != "" && v != "/" {
+				source.Path = github.String(v)
+			}
 		}
 	}
-	return &github.Pages{Source: source}
+	var buildType *string
+	if v, ok := pages["build_type"].(string); ok {
+		buildType = github.String(v)
+	}
+
+	return &github.Pages{Source: source, BuildType: buildType}
 }
 
 func expandPagesUpdate(input []interface{}) *github.PagesUpdate {
@@ -854,21 +872,24 @@ func expandPagesUpdate(input []interface{}) *github.PagesUpdate {
 		update.CNAME = github.String(v)
 	}
 
+	// Only set the github.PagesUpdate BuildType field if the value is a non-empty string.
+	if v, ok := pages["build_type"].(string); ok && v != "" {
+		update.BuildType = github.String(v)
+	}
+
 	// To update the GitHub Pages source, the github.PagesUpdate Source field
 	// must include the branch name and optionally the subdirectory /docs.
 	// e.g. "master" or "master /docs"
-	pagesSource := pages["source"].([]interface{})[0].(map[string]interface{})
-	sourceBranch := pagesSource["branch"].(string)
-	sourcePath := ""
-	if v, ok := pagesSource["path"].(string); ok {
-		if v != "" && v != "/" {
+	// This is only necessary if the BuildType is "legacy".
+	if update.BuildType == nil || *update.BuildType == "legacy" {
+		pagesSource := pages["source"].([]interface{})[0].(map[string]interface{})
+		sourceBranch := pagesSource["branch"].(string)
+		sourcePath := ""
+		if v, ok := pagesSource["path"].(string); ok && v != "" {
 			sourcePath = v
 		}
+		update.Source = &github.PagesSource{Branch: &sourceBranch, Path: &sourcePath}
 	}
-	update.Source = &github.PagesSource{Branch: &sourceBranch, Path: &sourcePath}
-
-	pagesBuildType := pages["build_type"].(string)
-	update.BuildType = &pagesBuildType
 
 	return update
 }