Add autofix support

go.mod

@@ -9,7 +9,7 @@ require (
 	github.com/hashicorp/go-version v1.6.0
 	github.com/hashicorp/hcl/v2 v2.16.2
 	github.com/hashicorp/terraform-registry-address v0.2.0
-	github.com/terraform-linters/tflint-plugin-sdk v0.16.1
+	github.com/terraform-linters/tflint-plugin-sdk v0.16.2-0.20230521152637-98b8c1069ddb
 	github.com/zclconf/go-cty v1.13.1
 )
 

go.sum

@@ -407,8 +407,8 @@ github.com/stretchr/testify v1.7.2/go.mod h1:R6va5+xMeoiuVRoj+gSkQ7d3FALtqAAGI1F
 github.com/stretchr/testify v1.8.0/go.mod h1:yNjHg4UonilssWZ8iaSj1OCr/vHnekPRkoO+kdMU+MU=
 github.com/stretchr/testify v1.8.1 h1:w7B6lhMri9wdJUVmEZPGGhZzrYTPvgJArz7wNPgYKsk=
 github.com/stretchr/testify v1.8.1/go.mod h1:w2LPCIKwWwSfY2zedu0+kehJoqGctiVI29o6fzry7u4=
-github.com/terraform-linters/tflint-plugin-sdk v0.16.1 h1:fBfLL8KzP3pkQrNp3iQxaGoKBoMo2sFYoqmhuo6yc+A=
-github.com/terraform-linters/tflint-plugin-sdk v0.16.1/go.mod h1:ltxVy04PRwptL6P/Ugz2ZeTNclYapClrLn/kVFXJGzo=
+github.com/terraform-linters/tflint-plugin-sdk v0.16.2-0.20230521152637-98b8c1069ddb h1:7oOZV08MmoTqSyEm1C340d5AkdgTZxkK9zcBIi58Tus=
+github.com/terraform-linters/tflint-plugin-sdk v0.16.2-0.20230521152637-98b8c1069ddb/go.mod h1:ltxVy04PRwptL6P/Ugz2ZeTNclYapClrLn/kVFXJGzo=
 github.com/ulikunitz/xz v0.5.10 h1:t92gobL9l3HE202wg3rlk19F6X+JOxl9BBrCCMYEYd8=
 github.com/ulikunitz/xz v0.5.10/go.mod h1:nbz6k7qbPmH4IRqmfOplQw/tblSgqTqBwxkY0oWt/14=
 github.com/vmihailenco/msgpack/v5 v5.3.5 h1:5gO0H1iULLWGhs2H5tbAHIZTV8/cYafcFOr9znI5mJU=

rules/terraform_comment_syntax.go

@@ -79,10 +79,13 @@ func (r *TerraformCommentSyntaxRule) checkComments(runner tflint.Runner, filenam
 		}
 
 		if strings.HasPrefix(string(token.Bytes), "//") {
-			if err := runner.EmitIssue(
+			if err := runner.EmitIssueWithFix(
 				r,
 				"Single line comments should begin with #",
 				token.Range,
+				func(f *tflint.Fixer) error {
+					return f.ReplaceText(f.RangeTo("//", filename, token.Range.Start), "#")
+				},
 			); err != nil {
 				return err
 			}

rules/terraform_comment_syntax_test.go

@@ -13,6 +13,7 @@ func Test_TerraformCommentSyntaxRule(t *testing.T) {
 		Content  string
 		JSON     bool
 		Expected helper.Issues
+		Fixed    string
 	}{
 		{
 			Name:     "hash comment",
@@ -48,6 +49,7 @@ func Test_TerraformCommentSyntaxRule(t *testing.T) {
 					},
 				},
 			},
+			Fixed: `# foo`,
 		},
 		{
 			Name: "end-of-line hash comment",
@@ -82,6 +84,11 @@ variable "foo" {
 			}
 
 			helper.AssertIssues(t, tc.Expected, runner.Issues)
+			want := map[string]string{}
+			if tc.Fixed != "" {
+				want[filename] = tc.Fixed
+			}
+			helper.AssertChanges(t, want, runner.Changes())
 		})
 	}
 }

rules/terraform_deprecated_index.go

@@ -1,6 +1,7 @@
 package rules
 
 import (
+	"fmt"
 	"strings"
 
 	"github.com/hashicorp/hcl/v2"
@@ -66,15 +67,18 @@ func (r *TerraformDeprecatedIndexRule) Check(runner tflint.Runner) error {
 			r.checkLegacyTraversalIndex(runner, expr.Traversal, file.Bytes)
 		case *hclsyntax.SplatExpr:
 			if strings.HasPrefix(string(expr.MarkerRange.SliceBytes(file.Bytes)), ".") {
-				if err := runner.EmitIssue(
+				if err := runner.EmitIssueWithFix(
 					r,
 					"List items should be accessed using square brackets",
 					expr.MarkerRange,
+					func(f *tflint.Fixer) error {
+						return f.ReplaceText(expr.MarkerRange, "[*]")
+					},
 				); err != nil {
 					return hcl.Diagnostics{
 						{
 							Severity: hcl.DiagError,
-							Summary:  "failed to call EmitIssue()",
+							Summary:  "failed to call EmitIssueWithFix()",
 							Detail:   err.Error(),
 						},
 					}
@@ -92,17 +96,21 @@ func (r *TerraformDeprecatedIndexRule) Check(runner tflint.Runner) error {
 
 func (r *TerraformDeprecatedIndexRule) checkLegacyTraversalIndex(runner tflint.Runner, traversal hcl.Traversal, file []byte) hcl.Diagnostics {
 	for _, t := range traversal {
-		if _, ok := t.(hcl.TraverseIndex); ok {
+		if tn, ok := t.(hcl.TraverseIndex); ok {
 			if strings.HasPrefix(string(t.SourceRange().SliceBytes(file)), ".") {
-				if err := runner.EmitIssue(
+				if err := runner.EmitIssueWithFix(
 					r,
 					"List items should be accessed using square brackets",
 					t.SourceRange(),
+					func(f *tflint.Fixer) error {
+						// TODO: handle non-numeric indices
+						return f.ReplaceText(t.SourceRange(), fmt.Sprintf("[%s]", tn.Key.AsBigFloat().Text('f', -1)))
+					},
 				); err != nil {
 					return hcl.Diagnostics{
 						{
 							Severity: hcl.DiagError,
-							Summary:  "failed to call EmitIssue()",
+							Summary:  "failed to call EmitIssueWithFix()",
 							Detail:   err.Error(),
 						},
 					}

rules/terraform_deprecated_index_test.go

@@ -12,6 +12,7 @@ func Test_TerraformDeprecatedIndexRule(t *testing.T) {
 		Name     string
 		Content  string
 		Expected helper.Issues
+		Fixed    string
 	}{
 		{
 			Name: "deprecated dot index style",
@@ -38,6 +39,12 @@ locals {
 					},
 				},
 			},
+			Fixed: `
+locals {
+  list = ["a"]
+  value = list[0]
+}
+`,
 		},
 		{
 			Name: "deprecated dot splat index style",
@@ -64,6 +71,12 @@ locals {
 					},
 				},
 			},
+			Fixed: `
+locals {
+  maplist = [{a = "b"}]
+  values = maplist[*].a
+}
+`,
 		},
 		{
 			Name: "attribute access",
@@ -100,14 +113,14 @@ EOF
 		{
 			Name: "directive: invalid",
 			Content: `
-		locals {
-		  servers = <<EOF
-		%{ for ip in aws_instance.example.*.private_ip }
-		server ${ip}
-		%{ endfor }
-		EOF
-		}
-		`,
+locals {
+  servers = <<EOF
+%{ for ip in aws_instance.example.*.private_ip }
+server ${ip}
+%{ endfor }
+EOF
+}
+`,
 			Expected: helper.Issues{
 				{
 					Rule:    NewTerraformDeprecatedIndexRule(),
@@ -116,15 +129,24 @@ EOF
 						Filename: "config.tf",
 						Start: hcl.Pos{
 							Line:   4,
-							Column: 36,
+							Column: 34,
 						},
 						End: hcl.Pos{
 							Line:   4,
-							Column: 38,
+							Column: 36,
 						},
 					},
 				},
 			},
+			Fixed: `
+locals {
+  servers = <<EOF
+%{ for ip in aws_instance.example[*].private_ip }
+server ${ip}
+%{ endfor }
+EOF
+}
+`,
 		},
 		{
 			Name: "legacy splat and legacy index",
@@ -166,6 +188,12 @@ locals {
 					},
 				},
 			},
+			Fixed: `
+locals {
+  nested_list = [["a"]]
+  value = nested_list[*][0]
+}
+`,
 		},
 		{
 			Name: "complex expression",
@@ -192,6 +220,12 @@ locals {
 					},
 				},
 			},
+			Fixed: `
+locals {
+  create_namespace = true
+  kubernetes_namespace = local.create_namespace ? join("", kubernetes_namespace.default[*].id) : var.kubernetes_namespace
+}
+`,
 		},
 	}
 
@@ -206,6 +240,11 @@ locals {
 			}
 
 			helper.AssertIssues(t, tc.Expected, runner.Issues)
+			want := map[string]string{}
+			if tc.Fixed != "" {
+				want["config.tf"] = tc.Fixed
+			}
+			helper.AssertChanges(t, want, runner.Changes())
 		})
 	}
 }

rules/terraform_deprecated_interpolation.go

@@ -60,20 +60,35 @@ func (r *TerraformDeprecatedInterpolationRule) Check(runner tflint.Runner) error
 }
 
 func (r *TerraformDeprecatedInterpolationRule) checkForDeprecatedInterpolationsInExpr(runner tflint.Runner, expr hcl.Expression) hcl.Diagnostics {
-	if _, ok := expr.(*hclsyntax.TemplateWrapExpr); !ok {
+	wrapExpr, ok := expr.(*hclsyntax.TemplateWrapExpr)
+	if !ok {
 		return nil
 	}
 
-	err := runner.EmitIssue(
+	err := runner.EmitIssueWithFix(
 		r,
 		"Interpolation-only expressions are deprecated in Terraform v0.12.14",
 		expr.Range(),
+		func(f *tflint.Fixer) error {
+			if err := f.Remove(hcl.Range{
+				Filename: expr.Range().Filename,
+				Start:    expr.Range().Start,
+				End:      wrapExpr.Wrapped.Range().Start,
+			}); err != nil {
+				return err
+			}
+			return f.Remove(hcl.Range{
+				Filename: expr.Range().Filename,
+				Start:    wrapExpr.Wrapped.Range().End,
+				End:      expr.Range().End,
+			})
+		},
 	)
 	if err != nil {
 		return hcl.Diagnostics{
 			{
 				Severity: hcl.DiagError,
-				Summary:  "failed to call EmitIssue()",
+				Summary:  "failed to call EmitIssueWithFix()",
 				Detail:   err.Error(),
 			},
 		}

rules/terraform_deprecated_interpolation_test.go

@@ -12,6 +12,7 @@ func Test_TerraformDeprecatedInterpolationRule(t *testing.T) {
 		Name     string
 		Content  string
 		Expected helper.Issues
+		Fixed    string
 	}{
 		{
 			Name: "deprecated single interpolation",
@@ -30,6 +31,10 @@ resource "null_resource" "a" {
 					},
 				},
 			},
+			Fixed: `
+resource "null_resource" "a" {
+	triggers = var.triggers
+}`,
 		},
 		{
 			Name: "deprecated single interpolation in provider block",
@@ -48,6 +53,10 @@ provider "null" {
 					},
 				},
 			},
+			Fixed: `
+provider "null" {
+	foo = var.triggers["foo"]
+}`,
 		},
 		{
 			Name: "deprecated single interpolation in locals block",
@@ -66,6 +75,10 @@ locals {
 					},
 				},
 			},
+			Fixed: `
+locals {
+	foo = var.triggers["foo"]
+}`,
 		},
 		{
 			Name: "deprecated single interpolation in nested block",
@@ -86,6 +99,12 @@ resource "null_resource" "a" {
 					},
 				},
 			},
+			Fixed: `
+resource "null_resource" "a" {
+	provisioner "local-exec" {
+		single = var.triggers["greeting"]
+	}
+}`,
 		},
 		{
 			Name: "interpolation as template",
@@ -112,6 +131,10 @@ resource "null_resource" "a" {
 					},
 				},
 			},
+			Fixed: `
+resource "null_resource" "a" {
+	triggers = [var.triggers]
+}`,
 		},
 		{
 			Name: "new interpolation syntax",
@@ -121,6 +144,37 @@ resource "null_resource" "a" {
 }`,
 			Expected: helper.Issues{},
 		},
+		{
+			Name: "nested wraps",
+			Content: `
+resource "null_resource" "a" {
+	triggers = "${"${var.triggers}"}"
+}`,
+			Expected: helper.Issues{
+				{
+					Rule:    NewTerraformDeprecatedInterpolationRule(),
+					Message: "Interpolation-only expressions are deprecated in Terraform v0.12.14",
+					Range: hcl.Range{
+						Filename: "config.tf",
+						Start:    hcl.Pos{Line: 3, Column: 13},
+						End:      hcl.Pos{Line: 3, Column: 35},
+					},
+				},
+				{
+					Rule:    NewTerraformDeprecatedInterpolationRule(),
+					Message: "Interpolation-only expressions are deprecated in Terraform v0.12.14",
+					Range: hcl.Range{
+						Filename: "config.tf",
+						Start:    hcl.Pos{Line: 3, Column: 16},
+						End:      hcl.Pos{Line: 3, Column: 33},
+					},
+				},
+			},
+			Fixed: `
+resource "null_resource" "a" {
+	triggers = var.triggers
+}`,
+		},
 	}
 
 	rule := NewTerraformDeprecatedInterpolationRule()
@@ -134,6 +188,11 @@ resource "null_resource" "a" {
 			}
 
 			helper.AssertIssues(t, tc.Expected, runner.Issues)
+			want := map[string]string{}
+			if tc.Fixed != "" {
+				want["config.tf"] = tc.Fixed
+			}
+			helper.AssertChanges(t, want, runner.Changes())
 		})
 	}
 }