fix small pr suggestions

Signed-off-by: Andrei Ciobanu <andrei.ciobanu@opentofu.org>

internal/backend/local/backend_local.go

@@ -446,7 +446,7 @@ func (b *Local) interactiveCollectVariables(ctx context.Context, existing map[st
 		rawValue, err := uiInput.Input(ctx, &tofu.InputOpts{
 			Id:          fmt.Sprintf("var.%s", name),
 			Query:       fmt.Sprintf("var.%s", name),
-			Description: variableInputDescription(vc),
+			Description: vc.InputPrompt(),
 			Secret:      vc.Sensitive,
 		})
 		if err != nil {
@@ -461,21 +461,6 @@ func (b *Local) interactiveCollectVariables(ctx context.Context, existing map[st
 	return ret
 }
 
-// variableInputDescription compiles a message for the description when the variable input is needed.
-// This is returning only the configs.Variable#Description if the variable is not deprecated,
-// or it returns both, the description and the deprecation message in one string to be able to
-// notify the user about the deprecation of the variable.
-func variableInputDescription(v *configs.Variable) string {
-	switch {
-	case v.Description != "" && v.DeprecatedSet:
-		return fmt.Sprintf("%s.\nVariable is marked as deprecated with the following message: %s", v.Description, v.Deprecated)
-	case v.DeprecatedSet:
-		return fmt.Sprintf("Variable is marked as deprecated with the following message: %s", v.Deprecated)
-	default:
-		return v.Description
-	}
-}
-
 // stubUnsetVariables ensures that all required variables defined in the
 // configuration exist in the resulting map, by adding new elements as necessary.
 //

internal/command/meta_config.go

@@ -164,18 +164,11 @@ func (m *Meta) getInput(ctx context.Context, variable *configs.Variable) (string
 		return "", fmt.Errorf("input is disabled")
 	}
 
-	varDesc := variable.Description
-	switch {
-	case variable.Description != "" && variable.DeprecatedSet:
-		varDesc = fmt.Sprintf("%s.\nVariable is marked as deprecated with the following message: %s", variable.Description, variable.Deprecated)
-	case variable.DeprecatedSet:
-		varDesc = fmt.Sprintf("Variable is marked as deprecated with the following message: %s", variable.Deprecated)
-	}
 	uiInput := m.UIInput()
 	rawValue, err := uiInput.Input(ctx, &tofu.InputOpts{
 		Id:          fmt.Sprintf("var.%s", variable.Name),
 		Query:       fmt.Sprintf("var.%s", variable.Name),
-		Description: varDesc,
+		Description: variable.InputPrompt(),
 		Secret:      variable.Sensitive,
 	})
 	if err != nil {

internal/configs/config_test.go

@@ -709,6 +709,25 @@ func TestConfigImportProviderWithNoResourceProvider(t *testing.T) {
 	})
 }
 
+func TestConfigWithDeprecatedVariables(t *testing.T) {
+	src, err := os.ReadFile("testdata/variable-empty-deprecated/main.tf")
+	if err != nil {
+		t.Fatal(err)
+	}
+
+	parser := testParser(map[string]string{
+		"main.tf": string(src),
+	})
+
+	_, diags := parser.LoadConfigFile("main.tf")
+	// The lack of a diagnostic for the "without_deprecated" variable validates also that a variable without any "deprecated" field specified
+	// is parsed correctly
+	assertExactDiagnostics(t, diags, []string{
+		`main.tf:1,10-33: Invalid deprecated value; The variable name "with_empty_deprecated" 'deprecated' field is defined but is empty.`,
+		`main.tf:7,10-39: Invalid deprecated value; The variable name "with_deprecated_only_spaces" 'deprecated' field is defined but is empty.`,
+	})
+}
+
 func TestTransformForTest(t *testing.T) {
 
 	str := func(providers map[string]string) string {

internal/configs/module_merge.go

@@ -51,9 +51,8 @@ func (v *Variable) merge(ov *Variable) hcl.Diagnostics {
 		v.Sensitive = ov.Sensitive
 		v.SensitiveSet = ov.SensitiveSet
 	}
-	if ov.DeprecatedSet {
+	if ov.Deprecated != "" {
 		v.Deprecated = ov.Deprecated
-		v.DeprecatedSet = ov.DeprecatedSet
 	}
 	if ov.Default != cty.NilVal {
 		v.Default = ov.Default

internal/configs/module_merge_test.go

@@ -31,7 +31,6 @@ func TestModuleOverrideVariable(t *testing.T) {
 			DescriptionSet: true,
 			Default:        cty.StringVal("b_override"),
 			Deprecated:     "b_override deprecated",
-			DeprecatedSet:  true,
 			Nullable:       false,
 			NullableSet:    true,
 			Type:           cty.String,
@@ -57,7 +56,6 @@ func TestModuleOverrideVariable(t *testing.T) {
 			DescriptionSet: true,
 			Default:        cty.StringVal("b_override partial"),
 			Deprecated:     "b_override deprecated",
-			DeprecatedSet:  true,
 			Nullable:       true,
 			NullableSet:    false,
 			Type:           cty.String,

internal/configs/named_values.go

@@ -7,6 +7,7 @@ package configs
 
 import (
 	"fmt"
+	"strings"
 
 	"github.com/hashicorp/hcl/v2"
 	"github.com/hashicorp/hcl/v2/ext/typeexpr"
@@ -42,7 +43,6 @@ type Variable struct {
 
 	DescriptionSet bool
 	SensitiveSet   bool
-	DeprecatedSet  bool
 
 	// Nullable indicates that null is a valid value for this variable. Setting
 	// Nullable to false means that the module can expect this variable to
@@ -127,8 +127,15 @@ func decodeVariableBlock(block *hcl.Block, override bool) (*Variable, hcl.Diagno
 
 	if attr, exists := content.Attributes["deprecated"]; exists {
 		valDiags := gohcl.DecodeExpression(attr.Expr, nil, &v.Deprecated)
+		if strings.TrimSpace(v.Deprecated) == "" {
+			diags = append(diags, &hcl.Diagnostic{
+				Severity: hcl.DiagError,
+				Summary:  "Invalid deprecated value",
+				Detail:   fmt.Sprintf("The variable name %q 'deprecated' field is defined but is empty.", v.Name),
+				Subject:  &block.LabelRanges[0],
+			})
+		}
 		diags = append(diags, valDiags...)
-		v.DeprecatedSet = true
 	}
 
 	if attr, exists := content.Attributes["nullable"]; exists {
@@ -288,6 +295,22 @@ func (v *Variable) Required() bool {
 	return v.Default == cty.NilVal
 }
 
+// InputPrompt returns the text that will be shown during prompting for the variable input when required but on value given.
+// This method is meant to return also the deprecated message together with the description when both exists or only the
+// deprecated info when the description is missing.
+// Other than these 2 cases, the method is keeping the default behavior in case of both (deprecated and description missing),
+// by returning the description. This will keep the previous behavior where during prompting will be shown only the
+// variable name.
+func (v *Variable) InputPrompt() string {
+	switch {
+	case v.Description != "" && v.Deprecated != "":
+		return fmt.Sprintf("%s.\nVariable is marked as deprecated with the following message: %s", v.Description, v.Deprecated)
+	case v.Deprecated != "":
+		return fmt.Sprintf("Variable is marked as deprecated with the following message: %s", v.Deprecated)
+	}
+	return v.Description
+}
+
 // VariableParsingMode defines how values of a particular variable given by
 // text-only mechanisms (command line arguments and environment variables)
 // should be parsed to produce the final value.

internal/configs/testdata/variable-empty-deprecated/main.tf

@@ -0,0 +1,16 @@
+variable "with_empty_deprecated" {
+  type = string
+  description = "variable that is having the deprecated field specified but is having no value"
+  deprecated = ""
+}
+
+variable "with_deprecated_only_spaces" {
+  type = string
+  description = "variable that is having the deprecated field specified only with blank characters"
+  deprecated = "   "
+}
+
+variable "without_deprecated" {
+  type = string
+  description = "no deprecated field defined so it should work fine"
+}

internal/tofu/eval_variable.go

@@ -480,7 +480,7 @@ You can correct this by removing references to sensitive values, or by carefully
 
 // evalVariableDeprecation checks if a variable is deprecated and if so it returns a warning diagnostic to be shown to the user
 func evalVariableDeprecation(addr addrs.AbsInputVariableInstance, config *configs.Variable, expr hcl.Expression, ctx EvalContext) tfdiags.Diagnostics {
-	if !config.DeprecatedSet {
+	if config.Deprecated == "" {
 		log.Printf("[TRACE] evalVariableDeprecation: variable %s is having no deprecation configured", addr)
 		return nil
 	}
@@ -490,7 +490,7 @@ func evalVariableDeprecation(addr addrs.AbsInputVariableInstance, config *config
 		return nil
 	}
 	val := ctx.GetVariableValue(addr)
-	if val.IsNull() {
+	if val == cty.NilVal || val.IsNull() {
 		log.Printf("[TRACE] evalVariableDeprecation: variable %s is marked as deprecated null value given", addr)
 		return nil
 	}