CORE-3855: Enable parallel testing (#24)

CORE-3855. This enables using `t.Parallel()` in tests by ensuring every test
is running in its own directory.

See details in https://pkg.go.dev/github.com/gruntwork-io/terratest@v0.40.20/modules/test-structure#CopyTerraformFolderToTemp

.github/workflows/pre-commit.yaml

@@ -19,7 +19,7 @@ jobs:
  - uses: actions/setup-python@c4e89fac7e8767b327bbad6cb4d859eda999cf08 # tag=v4
  - uses: actions/setup-go@84cbf8094393cdc5fe1fe1671ff2647332956b1a # tag=v3.2.1
  with:
- go-version: 1.18.4
+ go-version: 1.21.3
 
  - name: Setup for pre-commit
  run: make setup

README.md

@@ -43,6 +43,8 @@ You can use the `DefaultOptions` function for default terraformOptions to be set
 - `TerraformDir`, set to the absolute path of the module as the tests are in a subdirectory named `tests`
 - `VarFiles` is appended the with the `.tfvars` file in `test/variables` that has the same as the running test
 
+Using `DefaultOptions` ensures that the module directory is copied so that tests can be run in parallel with `t.Parallel()`
+
 ### Stages
 
 :information_source: You need stages if you expect e.g. the `terraform plan` to fail for a test and want to validate the errors that occur, see the examples below.
@@ -64,6 +66,10 @@ Available stages are:
 
 ```go
 func TestDefaults(t *testing.T) {
+ // If the test needs to run on its own, e.g. because
+ // of quota limitations, remove this line
+ t.Parallel()
+
  helpers.RunNoValidate(t)
 }
 ```
@@ -76,6 +82,10 @@ When you need to define not only constant variables, but also dynamic ones, you
 
 ```go
 func TestWithVars(t *testing.T) {
+ // If the test needs to run on its own, e.g. because
+ // of quota limitations, remove this line
+ t.Parallel()
+
  helpers.RunOptionsNoValidate(t, &terraform.Options{
  Vars: map[string]interface{}{
  "name": uuid.New(),
@@ -92,18 +102,18 @@ If a test is expected to fail on apply, defer the `destroy` stage and pass an er
 
 ```go
 func TestS3BucketDefault(t *testing.T) {
- defer helpers.StageDestroy(t, TerraformDir)
+ t.Parallel()
+ terraformOptions := defaultOptions(t)
 
  // set everything up for the terraform apply later
- terraformOptions := terraform.WithDefaultRetryableErrors(t, &terraform.Options{
- TerraformDir: TerraformDir,
- Vars: map[string]interface{}{
- "name": uuid.New(),
- },
- })
+ terraformOptions.Vars = map[string]interface{}{
+ "name": uuid.New(),
+ }
 
- helpers.StageSetup(t, TerraformDir, terraformOptions)
- helpers.StageApply(t, TerraformDir, func(err error, stdoutStderr string) {
+ defer helpers.StageDestroy(t, terraformOptions.TerraformDir)
+
+ helpers.StageSetup(t, terraformOptions.TerraformDir, terraformOptions)
+ helpers.StageApply(t, terraformOptions.TerraformDir, func(err error, stdoutStderr string) {
  // This error is expected
  if err != nil {
  if !strings.Contains(stdoutStderr, "Error: Some expected error") {
@@ -120,21 +130,20 @@ For a test that is expected to fail on plan, use the `Cleanup` function.
 
 ```go
 func TestS3BucketBackupOnVersioningOff(t *testing.T) {
- defer helpers.Cleanup(t, TerraformDir)
+ t.Parallel()
+ terraformOptions := defaultOptions(t)
 
- terraformOptions := terraform.WithDefaultRetryableErrors(t, &terraform.Options{
- TerraformDir: TerraformDir,
- // NoColor is important for the string.Contains later
- NoColor: true,
- Vars: map[string]interface{}{
- "name": uuid.New(),
- "backup": "on",
- "versioning": "Disabled",
- },
- })
+ terraformOptions.NoColor = true
+ terraformOptions.Vars = map[string]interface{}{
+ "name": uuid.New(),
+ "backup": "on",
+ "versioning": "Disabled",
+ }
+
+ defer helpers.Cleanup(t, terraformOptions.TerraformDir)
 
  // The terraform plan is expected to fail as versioning can't be turned off with backups turned on.
- helpers.StageSetup(t, TerraformDir, terraformOptions, func(err error, stdoutStderr string) {
+ helpers.StageSetup(t, terraformOptions.TerraformDir, terraformOptions, func(err error, stdoutStderr string) {
  // This error is expected, the precondition failed
  if err != nil {
  if !strings.Contains(stdoutStderr, "Error: Resource precondition failed") || !strings.Contains(stdoutStderr, "Versioning cannot be disabled when backups are enabled") {

options.go

@@ -8,6 +8,7 @@ import (
 
  "github.com/gruntwork-io/terratest/modules/files"
  "github.com/gruntwork-io/terratest/modules/terraform"
+ test_structure "github.com/gruntwork-io/terratest/modules/test-structure"
  "github.com/stretchr/testify/assert"
 )
 
@@ -28,5 +29,9 @@ func DefaultOptions(t *testing.T, terraformOptions *terraform.Options) *terrafor
  terraformOptions.TerraformDir = filepath.Join(path, "../")
  }
 
+ // This enables parallel testing by ensuring that every TerraformDir lives in its own temporary path
+ tempTestFolder := test_structure.CopyTerraformFolderToTemp(t, terraformOptions.TerraformDir, ".")
+ terraformOptions.TerraformDir = tempTestFolder
+
  return terraform.WithDefaultRetryableErrors(t, terraformOptions)
 }

run.go

@@ -6,7 +6,7 @@ import (
  "github.com/gruntwork-io/terratest/modules/terraform"
 )
 
-func RunValidate(t *testing.T, terraformOptions terraform.Options, validateFunc func()) {
+func RunValidate(t *testing.T, _ terraform.Options, validateFunc func()) {
  RunOptionsValidate(t, &terraform.Options{}, validateFunc)
 }