plugin: Drop support for TFLint v0.45 and earlier

README.md

@@ -10,7 +10,7 @@ NOTE: This plugin system is experimental. This means that API compatibility is f
 
 ## Requirements
 
-- TFLint v0.42+
+- TFLint v0.46+
 - Go v1.23
 
 ## Usage

plugin/internal/fromproto/fromproto.go

@@ -343,12 +343,6 @@ func Error(err error) error {
 	switch t := st.Details()[0].(type) {
 	case *proto.ErrorDetail:
 		switch t.Code {
-		case proto.ErrorCode_ERROR_CODE_UNKNOWN_VALUE:
-			return tflint.ErrUnknownValue
-		case proto.ErrorCode_ERROR_CODE_NULL_VALUE:
-			return tflint.ErrNullValue
-		case proto.ErrorCode_ERROR_CODE_UNEVALUABLE:
-			return fmt.Errorf("%s%w", st.Message(), tflint.ErrUnevaluable)
 		case proto.ErrorCode_ERROR_CODE_SENSITIVE:
 			return tflint.ErrSensitive
 		}

plugin/internal/host2plugin/host2plugin_test.go

@@ -245,15 +245,15 @@ func TestVersionConstraints(t *testing.T) {
 			ServerImpl: func() string {
 				return ""
 			},
-			Want:     "",
+			Want:     minTFLintVersionConstraint.String(),
 			ErrCheck: neverHappend,
 		},
 		{
 			Name: "valid constraint",
 			ServerImpl: func() string {
 				return ">= 1.0"
 			},
-			Want:     ">= 1.0",
+			Want:     fmt.Sprintf(">= 1.0,%s", minTFLintVersionConstraint),
 			ErrCheck: neverHappend,
 		},
 		{
@@ -444,7 +444,7 @@ func TestApplyGlobalConfig(t *testing.T) {
 			},
 			LegacyHost: true,
 			ErrCheck: func(err error) bool {
-				return err == nil || err.Error() != "failed to satisfy version constraints; tflint-ruleset-test_ruleset requires >= 0.42, but TFLint version is 0.40 or 0.41"
+				return err == nil || err.Error() != fmt.Sprintf("failed to satisfy version constraints; tflint-ruleset-test_ruleset requires %s, but TFLint version is 0.40 or 0.41", minTFLintVersionConstraint)
 			},
 		},
 	}

plugin/internal/host2plugin/plugin.go

@@ -4,6 +4,7 @@ import (
 	"context"
 
 	plugin "github.com/hashicorp/go-plugin"
+	"github.com/hashicorp/go-version"
 	"github.com/terraform-linters/tflint-plugin-sdk/plugin/internal/proto"
 	"github.com/terraform-linters/tflint-plugin-sdk/tflint"
 	"google.golang.org/grpc"
@@ -12,6 +13,9 @@ import (
 // SDKVersion is the SDK version.
 const SDKVersion = "0.22.0"
 
+// minTFLintVersionConstraint presents the minimum version of TFLint that this SDK supports.
+var minTFLintVersionConstraint = version.MustConstraints(version.NewConstraint(">= 0.46"))
+
 // handShakeConfig is used for UX. ProcotolVersion will be updated by incompatible changes.
 var handshakeConfig = plugin.HandshakeConfig{
 	ProtocolVersion:  11,

plugin/internal/host2plugin/server.go

@@ -5,6 +5,7 @@ import (
 	"fmt"
 
 	"github.com/hashicorp/go-plugin"
+	"github.com/hashicorp/go-version"
 	"github.com/terraform-linters/tflint-plugin-sdk/internal"
 	"github.com/terraform-linters/tflint-plugin-sdk/logger"
 	"github.com/terraform-linters/tflint-plugin-sdk/plugin/internal/fromproto"
@@ -73,7 +74,18 @@ func (s *GRPCServer) GetRuleNames(ctx context.Context, req *proto.GetRuleNames_R
 // GetVersionConstraint returns a constraint of TFLint versions.
 func (s *GRPCServer) GetVersionConstraint(ctx context.Context, req *proto.GetVersionConstraint_Request) (*proto.GetVersionConstraint_Response, error) {
 	s.constraintChecked = true
-	return &proto.GetVersionConstraint_Response{Constraint: s.impl.VersionConstraint()}, nil
+	constraints := version.Constraints{}
+	var err error
+	if s.impl.VersionConstraint() != "" {
+		constraints, err = version.NewConstraint(s.impl.VersionConstraint())
+		if err != nil {
+			return nil, status.Error(codes.Internal, err.Error())
+		}
+	}
+	// Append a minimum supported version constraint
+	constraints = append(constraints, minTFLintVersionConstraint...)
+
+	return &proto.GetVersionConstraint_Response{Constraint: constraints.String()}, nil
 }
 
 // GetSDKVersion returns the SDK version.
@@ -90,7 +102,7 @@ func (s *GRPCServer) GetConfigSchema(ctx context.Context, req *proto.GetConfigSc
 func (s *GRPCServer) ApplyGlobalConfig(ctx context.Context, req *proto.ApplyGlobalConfig_Request) (*proto.ApplyGlobalConfig_Response, error) {
 	// TFLint v0.41 and earlier does not check version constraints.
 	if !s.constraintChecked {
-		return nil, status.Error(codes.FailedPrecondition, fmt.Sprintf("failed to satisfy version constraints; tflint-ruleset-%s requires >= 0.42, but TFLint version is 0.40 or 0.41", s.impl.RuleSetName()))
+		return nil, status.Error(codes.FailedPrecondition, fmt.Sprintf("failed to satisfy version constraints; tflint-ruleset-%s requires %s, but TFLint version is 0.40 or 0.41", s.impl.RuleSetName(), minTFLintVersionConstraint))
 	}
 
 	if req.Config == nil {

plugin/internal/plugin2host/plugin2host_test.go

@@ -1761,45 +1761,6 @@ func TestEvaluateExpr(t *testing.T) {
 				return err == nil || err.Error() != "unexpected error"
 			},
 		},
-		{
-			Name:       "server returns an unknown error",
-			Expr:       hclExpr(`1`),
-			TargetType: reflect.TypeOf(0),
-			ServerImpl: func(hcl.Expression, tflint.EvaluateExprOption) (cty.Value, error) {
-				return cty.Value{}, fmt.Errorf("unknown%w", tflint.ErrUnknownValue)
-			},
-			Want:        0,
-			GetFileImpl: fileExists,
-			ErrCheck: func(err error) bool {
-				return !errors.Is(err, tflint.ErrUnknownValue)
-			},
-		},
-		{
-			Name:       "server returns a null value error",
-			Expr:       hclExpr(`1`),
-			TargetType: reflect.TypeOf(0),
-			ServerImpl: func(hcl.Expression, tflint.EvaluateExprOption) (cty.Value, error) {
-				return cty.Value{}, fmt.Errorf("null value%w", tflint.ErrNullValue)
-			},
-			Want:        0,
-			GetFileImpl: fileExists,
-			ErrCheck: func(err error) bool {
-				return !errors.Is(err, tflint.ErrNullValue)
-			},
-		},
-		{
-			Name:       "server returns a unevaluable error",
-			Expr:       hclExpr(`1`),
-			TargetType: reflect.TypeOf(0),
-			ServerImpl: func(hcl.Expression, tflint.EvaluateExprOption) (cty.Value, error) {
-				return cty.Value{}, fmt.Errorf("unevaluable%w", tflint.ErrUnevaluable)
-			},
-			Want:        0,
-			GetFileImpl: fileExists,
-			ErrCheck: func(err error) bool {
-				return !errors.Is(err, tflint.ErrUnevaluable)
-			},
-		},
 		{
 			Name:       "server returns a sensitive error",
 			Expr:       hclExpr(`1`),