feat(tfvars): Add function to get .tfvars files from a directory

pkg/scenario/client.go

@@ -1,10 +1,15 @@
 package scenario
 
 import (
+	"fmt"
 	"path/filepath"
 	"testing"
 	"time"
 
+	"github.com/Excoriate/tftest/pkg/utils"
+
+	"github.com/Excoriate/tftest/pkg/tfvars"
+
 	"github.com/Excoriate/tftest/pkg/cloudprovider"
 	"github.com/Excoriate/tftest/pkg/validation"
 
@@ -118,6 +123,38 @@ func WithVarFiles(workdir string, varFiles ...string) OptFn {
 	}
 }
 
+func WithScannedTFVars(workdir, fixturesDir string) OptFn {
+	return func(o *Options) error {
+		if err := validation.IsValidTFDir(workdir); err != nil {
+			return err
+		}
+
+		fixturesDirPath := filepath.Join(workdir, fixturesDir)
+
+		if err := validation.IsValidTFDir(fixturesDirPath); err != nil {
+			return err
+		}
+
+		hasTFVars, err := validation.HasTFVarFiles(fixturesDirPath)
+		if err != nil {
+			return err
+		}
+
+		if !hasTFVars {
+			return fmt.Errorf("the Terraform module %s with this fixtures directory %s does not have any .tfvars files", workdir, fixturesDir)
+		}
+
+		tfVarsPath, tfVarsErr := tfvars.GetTFVarsFromWorkdir(workdir)
+		if tfVarsErr != nil {
+			return tfVarsErr
+		}
+
+		o.varFiles = utils.MergeSlices(o.varFiles, tfVarsPath)
+
+		return nil
+	}
+}
+
 func NewWithOptions(t *testing.T, workdir string, opts ...OptFn) (*Client, error) {
 	o := &Options{}
 	for _, opt := range opts {

pkg/tfvars/tfvars.go

@@ -0,0 +1,34 @@
+package tfvars
+
+import (
+	"fmt"
+	"os"
+	"path/filepath"
+)
+
+// GetTFVarsFromWorkdir scans the provided workdir directory for all .tfvars files
+// and returns their filenames. If workdir is empty, it returns an error.
+func GetTFVarsFromWorkdir(workdir string) ([]string, error) {
+	if workdir == "" {
+		return nil, fmt.Errorf("workdir cannot be empty")
+	}
+
+	var tfvarFiles []string
+
+	// Use filepath.Walk to traverse the directory tree rooted at workdir
+	err := filepath.Walk(workdir, func(path string, info os.FileInfo, err error) error {
+		if err != nil {
+			return err
+		}
+
+		if filepath.Ext(path) == ".tfvars" {
+			// If it does, add its filename to the slice
+			tfvarFiles = append(tfvarFiles, filepath.Base(path))
+		}
+
+		// Return nil to continue the walk
+		return nil
+	})
+
+	return tfvarFiles, err
+}

pkg/utils/data.go

@@ -0,0 +1,11 @@
+package utils
+
+func MergeSlices(slices ...[]string) []string {
+	var merged []string
+
+	for _, slice := range slices {
+		merged = append(merged, slice...)
+	}
+
+	return merged
+}

pkg/validation/terraform.go

@@ -79,3 +79,18 @@ func IsValidTFModuleDir(path string) error {
 
 	return nil
 }
+
+// HasTFVarFiles checks if the given directory has Terraform variable files.
+// If the directory does not have any Terraform variable files, it returns an error.
+func HasTFVarFiles(path string) (bool, error) {
+	if path == "" {
+		return false, nil
+	}
+
+	files, err := filepath.Glob(filepath.Join(path, "*.tfvars"))
+	if err != nil {
+		return false, fmt.Errorf("failed to list files in directory: %v", err)
+	}
+
+	return len(files) > 0, nil
+}

test/examples/simple/with_options_test.go

@@ -53,3 +53,11 @@ func TestWithRetryOptions(t *testing.T) {
 
 	s.Stg.PlanStage(t, s.GetTerraformOptions())
 }
+
+func TestWithScannedTFVars(t *testing.T) {
+	workdir := "../../data/tf-random"
+	s, err := scenario.NewWithOptions(t, workdir, scenario.WithScannedTFVars(workdir, "fixtures"))
+	assert.NoErrorf(t, err, "Failed to create scenario: %s", err)
+
+	s.Stg.PlanStage(t, s.GetTerraformOptions())
+}