configs: Custom variable validation is no longer experimental

All of the feedback from the experiment described enhancements that can
potentially be added later without breaking changes, so this change simply
removes the experiment gate from the feature as originally implemented
with no changes to its functionality.

Further enhancements may follow in later releases, but the goal of this
change is just to ship the feature exactly as it was under the experiment.

Most of the changes here are cleaning up the experiment opt-ins from our
test cases. The most important parts are in configs/experiments.go and in
experiments/experiment.go .

Author: apparentlymart

configs/experiments.go

@@ -139,18 +139,5 @@ func checkModuleExperiments(m *Module) hcl.Diagnostics {
 		}
 	*/
 
-	if !m.ActiveExperiments.Has(experiments.VariableValidation) {
-		for _, vc := range m.Variables {
-			if len(vc.Validations) != 0 {
-				diags = diags.Append(&hcl.Diagnostic{
-					Severity: hcl.DiagError,
-					Summary:  "Custom variable validation is experimental",
-					Detail:   "This feature is currently an opt-in experiment, subject to change in future releases based on feedback.\n\nActivate the feature for this module by adding variable_validation to the list of active experiments.",
-					Subject:  vc.Validations[0].DeclRange.Ptr(),
-				})
-			}
-		}
-	}
-
 	return diags
 }

configs/testdata/invalid-files/variable-validation-bad-msg.tf

@@ -1,8 +1,3 @@
-
-terraform {
-  experiments = [variable_validation]
-}
-
 variable "validation" {
   validation {
     condition     = var.validation != 4

configs/testdata/invalid-files/variable-validation-condition-badref.tf

@@ -1,8 +1,4 @@
 
-terraform {
-  experiments = [variable_validation]
-}
-
 locals {
   foo = 1
 }

configs/testdata/invalid-files/variable-validation-condition-noref.tf

@@ -1,8 +1,4 @@
 
-terraform {
-  experiments = [variable_validation]
-}
-
 variable "validation" {
   validation {
     condition     = true # ERROR: Invalid variable validation condition

configs/testdata/invalid-modules/variable-validation-without-optin/variable-validation-without-optin.tf

@@ -1,7 +1,3 @@
-terraform {
-  experiments = [variable_validation] # WARNING: Experimental feature "variable_validation" is active
-}
-
 variable "validation" {
   validation {
     condition     = var.validation == 5

…-files/variable_validation_experiment.tf …tdata/valid-files/variable_validation.tfconfigs/testdata/warning-files/variable_validation_experiment.tf renamed to configs/testdata/valid-files/variable_validation.tf configs/testdata/warning-files/variable_validation_experiment.tf renamed to configs/testdata/valid-files/variable_validation.tf

@@ -19,7 +19,7 @@ const (
 func init() {
 	// Each experiment constant defined above must be registered here as either
 	// a current or a concluded experiment.
-	registerCurrentExperiment(VariableValidation)
+	registerConcludedExperiment(VariableValidation, "Custom variable validation can now be used by default, without enabling an experiment.")
 }
 
 // GetCurrent takes an experiment name and returns the experiment value

experiments/experiment.go

@@ -1371,14 +1371,6 @@ func TestContext2Validate_variableCustomValidationsRoot(t *testing.T) {
 	// altogether. (Root module variables are never known during validation.)
 	m := testModuleInline(t, map[string]string{
 		"main.tf": `
-# This feature is currently experimental.
-# (If you're currently cleaning up after concluding the experiment,
-# remember to also clean up similar references in the configs package
-# under "invalid-files" and "invalid-modules".)
-terraform {
-  experiments = [variable_validation]
-}
-
 variable "test" {
   type = string
 

terraform/context_validate_test.go

@@ -1,11 +1,3 @@
-# This feature is currently experimental.
-# (If you're currently cleaning up after concluding the experiment,
-# remember to also clean up similar references in the configs package
-# under "invalid-files" and "invalid-modules".)
-terraform {
-  experiments = [variable_validation]
-}
-
 variable "test" {
   type = string