From 0a1264c54d9b8ac842c7621c3ad6dc163aac5e2a Mon Sep 17 00:00:00 2001
From: Masayuki Morita <minamijoyo@gmail.com>
Date: Wed, 4 Sep 2019 23:19:30 +0900
Subject: [PATCH] Set a version to attribute value only if the key exists

---
 tfupdate/provider.go       | 11 +++++++++--
 tfupdate/provider_test.go  | 36 ++++++++++++++++++++++++++++++++++++
 tfupdate/terraform.go      |  9 ++++++++-
 tfupdate/terraform_test.go | 34 ++++++++++++++++++++++++++++++++++
 4 files changed, 87 insertions(+), 3 deletions(-)

diff --git a/tfupdate/provider.go b/tfupdate/provider.go
index e2b9f3f..6f641f7 100644
--- a/tfupdate/provider.go
+++ b/tfupdate/provider.go
@@ -52,7 +52,11 @@ func (u *ProviderUpdater) updateTerraformBlock(f *hclwrite.File) error {
 	if p == nil {
 		return nil
 	}
-	p.Body().SetAttributeValue(u.name, cty.StringVal(u.version))
+
+	// set a version to attribute value only if the key exists
+	if p.Body().GetAttribute(u.name) != nil {
+		p.Body().SetAttributeValue(u.name, cty.StringVal(u.version))
+	}
 
 	return nil
 }
@@ -63,7 +67,10 @@ func (u *ProviderUpdater) updateProviderBlock(f *hclwrite.File) error {
 		return nil
 	}
 
-	p.Body().SetAttributeValue("version", cty.StringVal(u.version))
+	// set a version to attribute value only if the key exists
+	if p.Body().GetAttribute("version") != nil {
+		p.Body().SetAttributeValue("version", cty.StringVal(u.version))
+	}
 
 	return nil
 }
diff --git a/tfupdate/provider_test.go b/tfupdate/provider_test.go
index aaffb45..34319ce 100644
--- a/tfupdate/provider_test.go
+++ b/tfupdate/provider_test.go
@@ -97,6 +97,42 @@ provider "aws" {
   version = "2.23.0"
   region  = "ap-northeast-1"
 }
+`,
+			ok: true,
+		},
+		{
+			src: `
+terraform {
+  required_version = "0.12.4"
+  required_providers {
+    null = "2.1.1"
+  }
+}
+`,
+			name:    "aws",
+			version: "2.23.0",
+			want: `
+terraform {
+  required_version = "0.12.4"
+  required_providers {
+    null = "2.1.1"
+  }
+}
+`,
+			ok: true,
+		},
+		{
+			src: `
+provider "aws" {
+  region = "ap-northeast-1"
+}
+`,
+			name:    "aws",
+			version: "2.23.0",
+			want: `
+provider "aws" {
+  region = "ap-northeast-1"
+}
 `,
 			ok: true,
 		},
diff --git a/tfupdate/terraform.go b/tfupdate/terraform.go
index 4b94578..c5dfbe7 100644
--- a/tfupdate/terraform.go
+++ b/tfupdate/terraform.go
@@ -26,7 +26,14 @@ func NewTerraformUpdater(version string) (Updater, error) {
 // 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))
+	if tf == nil {
+		return nil
+	}
+
+	// set a version to attribute value only if the key exists
+	if tf.Body().GetAttribute("required_version") != nil {
+		tf.Body().SetAttributeValue("required_version", cty.StringVal(u.version))
+	}
 
 	return nil
 }
diff --git a/tfupdate/terraform_test.go b/tfupdate/terraform_test.go
index 3ceebbc..919480a 100644
--- a/tfupdate/terraform_test.go
+++ b/tfupdate/terraform_test.go
@@ -62,6 +62,40 @@ terraform {
 terraform {
   required_version = "0.12.7"
 }
+`,
+			ok: true,
+		},
+		{
+			src: `
+terraform {
+  required_providers {
+    null = "2.1.1"
+  }
+}
+`,
+			version: "0.12.7",
+			want: `
+terraform {
+  required_providers {
+    null = "2.1.1"
+  }
+}
+`,
+			ok: true,
+		},
+		{
+			src: `
+provider "aws" {
+  version = "2.11.0"
+  region  = "ap-northeast-1"
+}
+`,
+			version: "0.12.7",
+			want: `
+provider "aws" {
+  version = "2.11.0"
+  region  = "ap-northeast-1"
+}
 `,
 			ok: true,
 		},