Fix crash when passed --only with a configured rule

cmd/inspect.go

@@ -17,6 +17,11 @@ func (cli *CLI) inspect(opts Options, dir string, filterFiles []string) int {
 		cli.formatter.Print(tflint.Issues{}, tflint.NewContextError("Failed to load TFLint config", err), map[string][]byte{})
 		return ExitCodeError
 	}
+	if len(opts.Only) > 0 {
+		for _, rule := range cfg.Rules {
+			rule.Enabled = false
+		}
+	}
 	cfg = cfg.Merge(opts.toConfig())
 
 	// Setup loader

cmd/version.go

@@ -18,6 +18,11 @@ func (cli *CLI) printVersion(opts Options) int {
 		log.Printf("[ERROR] Failed to load TFLint config: %s", err)
 		return ExitCodeOK
 	}
+	if len(opts.Only) > 0 {
+		for _, rule := range cfg.Rules {
+			rule.Enabled = false
+		}
+	}
 	cfg = cfg.Merge(opts.toConfig())
 
 	cli.loader, err = tflint.NewLoader(afero.Afero{Fs: afero.NewOsFs()}, cfg)

integrationtest/bundled/bundled_test.go

@@ -75,6 +75,11 @@ func TestBundledPlugin(t *testing.T) {
 			Command: "tflint --enable-rule aws_s3_bucket_name --format json --force",
 			Dir:     "rule-config",
 		},
+		{
+			Name:    "rule config with --only",
+			Command: "tflint --only aws_s3_bucket_name --format json --force",
+			Dir:     "rule-config",
+		},
 	}
 
 	dir, _ := os.Getwd()

langserver/handler.go

@@ -26,6 +26,11 @@ func NewHandler(configPath string, cliConfig *tflint.Config) (jsonrpc2.Handler,
 	if err != nil {
 		return nil, nil, err
 	}
+	if cliConfig.DisabledByDefault {
+		for _, rule := range cfg.Rules {
+			rule.Enabled = false
+		}
+	}
 	cfg = cfg.Merge(cliConfig)
 
 	// AWS plugin is automatically enabled for the backward compatibility.

tflint/config.go

@@ -147,7 +147,7 @@ func (c *Config) Merge(other *Config) *Config {
 	ret.Varfiles = append(ret.Varfiles, other.Varfiles...)
 	ret.Variables = append(ret.Variables, other.Variables...)
 
-	ret.Rules = mergeRuleMap(ret.Rules, other.Rules, other.DisabledByDefault)
+	ret.Rules = mergeRuleMap(ret.Rules, other.Rules)
 	ret.Plugins = mergePluginMap(ret.Plugins, other.Plugins)
 
 	return ret
@@ -332,27 +332,8 @@ func mergeBoolMap(a, b map[string]bool) map[string]bool {
 	return ret
 }
 
-func mergeRuleMap(a, b map[string]*RuleConfig, bDisabledByDefault bool) map[string]*RuleConfig {
+func mergeRuleMap(a, b map[string]*RuleConfig) map[string]*RuleConfig {
 	ret := map[string]*RuleConfig{}
-	if bDisabledByDefault {
-		for bK, bV := range b {
-			configRuleFound := false
-			for aK, aV := range a {
-				if aK == bK {
-					ret[bK] = bV
-					ret[bK].Body = aV.Body
-					ret[bK].Enabled = true
-					configRuleFound = true
-				}
-			}
-			if !configRuleFound {
-				ret[bK] = bV
-				ret[bK].Enabled = true
-			}
-		}
-		return ret
-	}
-
 	for k, v := range a {
 		ret[k] = v
 	}

tflint/config_test.go

@@ -385,7 +385,7 @@ func Test_Merge(t *testing.T) {
 					},
 					"aws_instance_invalid_ami": {
 						Name:    "aws_instance_invalid_ami",
-						Enabled: true,
+						Enabled: false,
 						Body:    file1.Body,
 					},
 				},
@@ -455,6 +455,11 @@ func Test_Merge(t *testing.T) {
 						Enabled: true,
 						Body:    hcl.EmptyBody(),
 					},
+					"aws_instance_invalid_ami": {
+						Name:    "aws_instance_invalid_ami",
+						Enabled: false,
+						Body:    file1.Body,
+					},
 				},
 				Plugins: map[string]*PluginConfig{
 					"foo": {