Extract HCL rewrite logic into tfupdate package and updater interface

go.mod

@@ -4,6 +4,7 @@ go 1.12
 
 require (
 	github.com/hashicorp/hcl2 v0.0.0-20190809210004-72d32879a5c5
+	github.com/pkg/errors v0.8.1
 	github.com/zclconf/go-cty v1.0.0
 )
 

go.sum

@@ -31,6 +31,8 @@ github.com/mitchellh/go-wordwrap v0.0.0-20150314170334-ad45545899c7/go.mod h1:ZX
 github.com/onsi/ginkgo v1.6.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/ginkgo v1.7.0/go.mod h1:lLunBs/Ym6LB5Z9jYTR76FiuTmxDTDusOGeTQH+WWjE=
 github.com/onsi/gomega v1.4.3/go.mod h1:ex+gbHU/CVuBBDIJjb2X0qEXbFg53c61hWP/1CpauHY=
+github.com/pkg/errors v0.8.1 h1:iURUrRGxPUNPdy5/HRSm+Yj6okJ6UtLINN0Q9M4+h3I=
+github.com/pkg/errors v0.8.1/go.mod h1:bwawxfHBFNV+L2hUp1rHADufV3IMtnDRdf1r5NINEl0=
 github.com/pmezard/go-difflib v1.0.0 h1:4DBwDE0NGyQoBHbLQYPwSUPoCMWR5BEzIk/f1lZbAQM=
 github.com/pmezard/go-difflib v1.0.0/go.mod h1:iKH77koFhYxTK1pcRnkKkqfTogsbg7gZNVY4sRDYZ/4=
 github.com/sergi/go-diff v1.0.0 h1:Kpca3qRNrduNnOQeazBd0ysaKrUJiIuISHxogkT9RPQ=

main.go

@@ -8,40 +8,48 @@ import (
 
 	"github.com/hashicorp/hcl2/hcl"
 	"github.com/hashicorp/hcl2/hclwrite"
-	"github.com/zclconf/go-cty/cty"
+	"github.com/minamijoyo/tfupdate/tfupdate"
 )
 
 func main() {
 	filename := "./main.tf"
 
-	err := updateFile(filename)
+	updaterType := "terraform"
+	name := ""
+	version := "0.12.7"
+
+	// updaterType := "provider"
+	// name := "aws"
+	// version := "2.23.0"
+
+	err := updateFile(filename, updaterType, name, version)
 	if err != nil {
 		fmt.Fprintln(os.Stderr, err)
 		os.Exit(1)
 	}
 }
 
-func updateFile(filename string) error {
+func updateFile(filename string, updaterType string, name string, version string) error {
 	r, err := os.Open(filename)
 	if err != nil {
 		return fmt.Errorf("failed to open file: %+v", err)
 	}
 
-	err = update(r, filename, os.Stdout)
+	err = update(r, os.Stdout, filename, updaterType, name, version)
 	if err != nil {
 		return err
 	}
 
 	return nil
 }
 
-func update(r io.Reader, filename string, w io.Writer) error {
+func update(r io.Reader, w io.Writer, filename string, updaterType string, name string, version string) error {
 	f, err := parseHCL(r, filename)
 	if err != nil {
 		return err
 	}
 
-	err = updateHCL(f)
+	err = updateHCL(f, updaterType, name, version)
 	if err != nil {
 		return err
 	}
@@ -78,34 +86,11 @@ func writeHCL(f *hclwrite.File, w io.Writer) error {
 	return nil
 }
 
-func updateHCL(f *hclwrite.File) error {
-	err := updateTerraform(f)
-	if err != nil {
-		return err
-	}
-
-	err = updateProvider(f)
+func updateHCL(f *hclwrite.File, updaterType string, name string, version string) error {
+	u, err := tfupdate.NewUpdater(updaterType, name, version)
 	if err != nil {
 		return err
 	}
 
-	return nil
-}
-
-func updateTerraform(f *hclwrite.File) error {
-	tf := f.Body().FirstMatchingBlock("terraform", []string{})
-	tf.Body().SetAttributeValue("required_version", cty.StringVal("0.12.6"))
-
-	return nil
-}
-
-func updateProvider(f *hclwrite.File) error {
-	tf := f.Body().FirstMatchingBlock("terraform", []string{})
-	providers := tf.Body().FirstMatchingBlock("required_providers", []string{})
-	providers.Body().SetAttributeValue("null", cty.StringVal("2.1.2"))
-
-	aws := f.Body().FirstMatchingBlock("provider", []string{"aws"})
-	aws.Body().SetAttributeValue("version", cty.StringVal("2.23.0"))
-
-	return nil
+	return u.Update(f)
 }

tfupdate/provider.go

@@ -0,0 +1,69 @@
+package tfupdate
+
+import (
+	"github.com/hashicorp/hcl2/hclwrite"
+	"github.com/pkg/errors"
+	"github.com/zclconf/go-cty/cty"
+)
+
+// ProviderUpdater is a updater implementation which updates the provider version constraint.
+type ProviderUpdater struct {
+	name    string
+	version string
+}
+
+// NewProviderUpdater is a factory method which returns an ProviderUpdater instance.
+func NewProviderUpdater(name string, version string) (Updater, error) {
+	if len(name) == 0 {
+		return nil, errors.Errorf("failed to new provider updater. name is required.")
+	}
+
+	if len(version) == 0 {
+		return nil, errors.Errorf("failed to new provider updater. version is required.")
+	}
+
+	return &ProviderUpdater{
+		name:    name,
+		version: version,
+	}, nil
+}
+
+// Update updates the provider version constraint.
+// Note that this method will rewrite the AST passed as an argument.
+func (u *ProviderUpdater) Update(f *hclwrite.File) error {
+	if err := u.updateTerraformBlock(f); err != nil {
+		return err
+	}
+
+	if err := u.updateProviderBlock(f); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (u *ProviderUpdater) updateTerraformBlock(f *hclwrite.File) error {
+	tf := f.Body().FirstMatchingBlock("terraform", []string{})
+	if tf == nil {
+		return nil
+	}
+
+	p := tf.Body().FirstMatchingBlock("required_providers", []string{})
+	if p == nil {
+		return nil
+	}
+	p.Body().SetAttributeValue(u.name, cty.StringVal(u.version))
+
+	return nil
+}
+
+func (u *ProviderUpdater) updateProviderBlock(f *hclwrite.File) error {
+	p := f.Body().FirstMatchingBlock("provider", []string{u.name})
+	if p == nil {
+		return nil
+	}
+
+	p.Body().SetAttributeValue("version", cty.StringVal(u.version))
+
+	return nil
+}

tfupdate/provider_test.go

@@ -0,0 +1,128 @@
+package tfupdate
+
+import (
+	"reflect"
+	"testing"
+
+	"github.com/hashicorp/hcl2/hcl"
+	"github.com/hashicorp/hcl2/hclwrite"
+)
+
+func TestNewProviderUpdater(t *testing.T) {
+	cases := []struct {
+		name    string
+		version string
+		want    Updater
+		ok      bool
+	}{
+		{
+			name:    "aws",
+			version: "2.23.0",
+			want: &ProviderUpdater{
+				name:    "aws",
+				version: "2.23.0",
+			},
+			ok: true,
+		},
+		{
+			name:    "",
+			version: "2.23.0",
+			want:    nil,
+			ok:      false,
+		},
+		{
+			name:    "aws",
+			version: "",
+			want:    nil,
+			ok:      false,
+		},
+	}
+
+	for _, tc := range cases {
+		got, err := NewProviderUpdater(tc.name, tc.version)
+		if tc.ok && err != nil {
+			t.Errorf("NewProviderUpdater() with name = %s, version = %s returns unexpected err: %+v", tc.name, tc.version, err)
+		}
+
+		if !tc.ok && err == nil {
+			t.Errorf("NewProviderUpdater() with name = %s, version = %s expects to return an error, but no error: %+v", tc.name, tc.version, err)
+		}
+
+		if !reflect.DeepEqual(got, tc.want) {
+			t.Errorf("NewProviderUpdater() with name = %s, version = %s returns %#v, but want = %#v", tc.name, tc.version, got, tc.want)
+		}
+	}
+}
+
+func TestUpdateProvider(t *testing.T) {
+	cases := []struct {
+		src     string
+		name    string
+		version string
+		want    string
+		ok      bool
+	}{
+		{
+			src: `
+terraform {
+  required_version = "0.12.4"
+  required_providers {
+    null = "2.1.1"
+  }
+}
+`,
+			name:    "null",
+			version: "2.1.2",
+			want: `
+terraform {
+  required_version = "0.12.4"
+  required_providers {
+    null = "2.1.2"
+  }
+}
+`,
+			ok: true,
+		},
+		{
+			src: `
+provider "aws" {
+  version = "2.11.0"
+  region  = "ap-northeast-1"
+}
+`,
+			name:    "aws",
+			version: "2.23.0",
+			want: `
+provider "aws" {
+  version = "2.23.0"
+  region  = "ap-northeast-1"
+}
+`,
+			ok: true,
+		},
+	}
+
+	for _, tc := range cases {
+		u := &ProviderUpdater{
+			name:    tc.name,
+			version: tc.version,
+		}
+		f, diags := hclwrite.ParseConfig([]byte(tc.src), "", hcl.Pos{Line: 1, Column: 1})
+		if diags.HasErrors() {
+			t.Fatalf("unexpected diagnostics: %s", diags)
+		}
+
+		err := u.Update(f)
+		if tc.ok && err != nil {
+			t.Errorf("Update() with src = %s, name = %s, version = %s returns unexpected err: %+v", tc.src, tc.name, tc.version, err)
+		}
+		if !tc.ok && err == nil {
+			t.Errorf("Update() with src = %s, name = %s, version = %s expects to return an error, but no error", tc.src, tc.name, tc.version)
+		}
+
+		got := string(hclwrite.Format(f.BuildTokens(nil).Bytes()))
+		if got != tc.want {
+			t.Errorf("Update() with src = %s, name = %s, version = %s returns %s, but want = %s", tc.src, tc.name, tc.version, got, tc.want)
+		}
+	}
+}

tfupdate/terraform.go

@@ -0,0 +1,32 @@
+package tfupdate
+
+import (
+	"github.com/hashicorp/hcl2/hclwrite"
+	"github.com/pkg/errors"
+	"github.com/zclconf/go-cty/cty"
+)
+
+// TerraformUpdater is a updater implementation which updates the terraform version constraint.
+type TerraformUpdater struct {
+	version string
+}
+
+// NewTerraformUpdater is a factory method which returns an TerraformUpdater instance.
+func NewTerraformUpdater(version string) (Updater, error) {
+	if len(version) == 0 {
+		return nil, errors.Errorf("failed to new terraform updater. version is required.")
+	}
+
+	return &TerraformUpdater{
+		version: version,
+	}, nil
+}
+
+// Update updates the terraform version constraint.
+// Note that this method will rewrite the AST passed as an argument.
+func (u *TerraformUpdater) Update(f *hclwrite.File) error {
+	tf := f.Body().FirstMatchingBlock("terraform", []string{})
+	tf.Body().SetAttributeValue("required_version", cty.StringVal(u.version))
+
+	return nil
+}