support empty repositories w/o a single commit

docs/data-sources/repository.md

@@ -27,8 +27,8 @@ data "git_repository" "repository" {
 
 ### Read-Only
 
-- `branch` (String) The current branch of the given Git repository. Note that repositories in detached state might not have a branch associated with them.
+- `branch` (String) The name of the current branch of the given Git repository. Note that repositories in detached state might not have a branch associated with them.
 - `id` (String) The same value as the `directory` attribute.
-- `sha1` (String) The current SHA1 of the `HEAD` of the given Git repository.
+- `sha1` (String) The SHA1 of the current `HEAD` of the given Git repository.
 
 

internal/provider/data_source_git_repository.go

@@ -7,6 +7,7 @@ package provider
 
 import (
 	"context"
+	"github.com/go-git/go-git/v5/plumbing"
 	"github.com/hashicorp/terraform-plugin-framework-validators/stringvalidator"
 	"github.com/hashicorp/terraform-plugin-framework/datasource"
 	"github.com/hashicorp/terraform-plugin-framework/diag"
@@ -47,12 +48,12 @@ func (r *dataSourceGitRepositoryType) GetSchema(_ context.Context) (tfsdk.Schema
 				Computed:            true,
 			},
 			"branch": {
-				Description: "The current branch of the given Git repository. Note that repositories in detached state might not have a branch associated with them.",
+				Description: "The name of the current branch of the given Git repository. Note that repositories in detached state might not have a branch associated with them.",
 				Type:        types.StringType,
 				Computed:    true,
 			},
 			"sha1": {
-				MarkdownDescription: "The current SHA1 of the `HEAD` of the given Git repository.",
+				MarkdownDescription: "The SHA1 of the current `HEAD` of the given Git repository.",
 				Type:                types.StringType,
 				Computed:            true,
 			},
@@ -67,10 +68,9 @@ func (r *dataSourceGitRepositoryType) NewDataSource(_ context.Context, p provide
 }
 
 func (r *dataSourceGitRepository) Read(ctx context.Context, req datasource.ReadRequest, resp *datasource.ReadResponse) {
-	tflog.Debug(ctx, "Reading Git repository")
+	tflog.Debug(ctx, "Read git_repository")
 
 	var inputs dataSourceGitRepositorySchema
-	var state dataSourceGitRepositorySchema
 
 	diags := req.Config.Get(ctx, &inputs)
 	resp.Diagnostics.Append(diags...)
@@ -85,27 +85,31 @@ func (r *dataSourceGitRepository) Read(ctx context.Context, req datasource.ReadR
 		return
 	}
 
+	var state dataSourceGitRepositorySchema
+	state.Directory = inputs.Directory
+	state.Id = inputs.Directory
+
 	head, err := repository.Head()
-	if err != nil {
+	if err == plumbing.ErrReferenceNotFound {
+		state.SHA1 = types.String{Null: true}
+		state.Branch = types.String{Null: true}
+	} else if err != nil {
 		resp.Diagnostics.AddError(
 			"Error reading HEAD reference",
 			"Could not read HEAD of ["+directory+"] because of: "+err.Error(),
 		)
 		return
-	}
-
-	tflog.Trace(ctx, "read HEAD reference", map[string]interface{}{
-		"directory": directory,
-		"head":      head.String(),
-	})
-
-	state.Directory = inputs.Directory
-	state.Id = inputs.Directory
-	state.SHA1 = types.String{Value: head.Hash().String()}
-	if head.Name().IsBranch() {
-		state.Branch = types.String{Value: head.Name().Short()}
 	} else {
-		state.Branch = types.String{Null: true}
+		tflog.Trace(ctx, "read HEAD reference", map[string]interface{}{
+			"directory": directory,
+			"head":      head.String(),
+		})
+		state.SHA1 = types.String{Value: head.Hash().String()}
+		if head.Name().IsBranch() {
+			state.Branch = types.String{Value: head.Name().Short()}
+		} else {
+			state.Branch = types.String{Null: true}
+		}
 	}
 
 	diags = resp.State.Set(ctx, &state)

internal/provider/data_source_git_repository_test.go

@@ -69,6 +69,31 @@ func TestDataSourceGitRepository_Detached(t *testing.T) {
 	})
 }
 
+func TestDataSourceGitRepository_Empty(t *testing.T) {
+	t.Parallel()
+	directory, _ := testRepository(t)
+	defer os.RemoveAll(directory)
+
+	resource.UnitTest(t, resource.TestCase{
+		ProtoV6ProviderFactories: testProviderFactories(),
+		Steps: []resource.TestStep{
+			{
+				Config: fmt.Sprintf(`
+					data "git_repository" "test" {
+						directory = "%s"
+					}
+				`, directory),
+				Check: resource.ComposeAggregateTestCheckFunc(
+					resource.TestCheckResourceAttr("data.git_repository.test", "directory", directory),
+					resource.TestCheckResourceAttr("data.git_repository.test", "id", directory),
+					resource.TestCheckNoResourceAttr("data.git_repository.test", "branch"),
+					resource.TestCheckNoResourceAttr("data.git_repository.test", "sha1"),
+				),
+			},
+		},
+	})
+}
+
 func TestDataSourceGitRepository_InvalidRepository(t *testing.T) {
 	t.Parallel()
 	resource.UnitTest(t, resource.TestCase{