From 14d625c850270ba92927833300765ab8577d753d Mon Sep 17 00:00:00 2001
From: Kristin Laemmert <mildwonkey@users.noreply.github.com>
Date: Tue, 14 May 2019 16:19:31 -0400
Subject: [PATCH] configs/configupgrade: preserve in-line comments for lists
 (#21299)

* configs/configupgrade: preserve in-line comments for lists

The configupgrade tool was not writing `LineComments` for lists. Now it
is!

Fixes #21155
---
 .../valid/inline-comments/input/main.tf       | 25 +++++++++++++++++++
 .../valid/inline-comments/want/main.tf        | 25 +++++++++++++++++++
 .../valid/inline-comments/want/versions.tf    |  3 +++
 configs/configupgrade/upgrade_expr.go         | 15 ++++++++---
 4 files changed, 64 insertions(+), 4 deletions(-)
 create mode 100644 configs/configupgrade/test-fixtures/valid/inline-comments/input/main.tf
 create mode 100644 configs/configupgrade/test-fixtures/valid/inline-comments/want/main.tf
 create mode 100644 configs/configupgrade/test-fixtures/valid/inline-comments/want/versions.tf

diff --git a/configs/configupgrade/test-fixtures/valid/inline-comments/input/main.tf b/configs/configupgrade/test-fixtures/valid/inline-comments/input/main.tf
new file mode 100644
index 000000000..82123b303
--- /dev/null
+++ b/configs/configupgrade/test-fixtures/valid/inline-comments/input/main.tf
@@ -0,0 +1,25 @@
+variable "list" {
+  type = "list"
+
+  default = [
+    "foo", # I am a comment
+    "bar", # I am also a comment
+    "baz",
+  ]
+}
+
+variable "list2" {
+  type = "list"
+
+  default = [
+    "foo",
+    "bar",
+    "baz",
+  ]
+}
+
+variable "list_the_third" {
+  type = "list"
+
+  default = ["foo", "bar", "baz"]
+}
diff --git a/configs/configupgrade/test-fixtures/valid/inline-comments/want/main.tf b/configs/configupgrade/test-fixtures/valid/inline-comments/want/main.tf
new file mode 100644
index 000000000..256dc473b
--- /dev/null
+++ b/configs/configupgrade/test-fixtures/valid/inline-comments/want/main.tf
@@ -0,0 +1,25 @@
+variable "list" {
+  type = list(string)
+
+  default = [
+    "foo", # I am a comment
+    "bar", # I am also a comment
+    "baz",
+  ]
+}
+
+variable "list2" {
+  type = list(string)
+
+  default = [
+    "foo",
+    "bar",
+    "baz",
+  ]
+}
+
+variable "list_the_third" {
+  type = list(string)
+
+  default = ["foo", "bar", "baz"]
+}
\ No newline at end of file
diff --git a/configs/configupgrade/test-fixtures/valid/inline-comments/want/versions.tf b/configs/configupgrade/test-fixtures/valid/inline-comments/want/versions.tf
new file mode 100644
index 000000000..d9b6f790b
--- /dev/null
+++ b/configs/configupgrade/test-fixtures/valid/inline-comments/want/versions.tf
@@ -0,0 +1,3 @@
+terraform {
+  required_version = ">= 0.12"
+}
diff --git a/configs/configupgrade/upgrade_expr.go b/configs/configupgrade/upgrade_expr.go
index c8668202f..0be5f1448 100644
--- a/configs/configupgrade/upgrade_expr.go
+++ b/configs/configupgrade/upgrade_expr.go
@@ -168,10 +168,17 @@ Value:
 			src, moreDiags := upgradeExpr(node, filename, interp, an)
 			diags = diags.Append(moreDiags)
 			buf.Write(src)
-			if multiline {
-				buf.WriteString(",\n")
-			} else if i < len(tv.List)-1 {
-				buf.WriteString(", ")
+			if lit, ok := node.(*hcl1ast.LiteralType); ok && lit.LineComment != nil {
+				for _, comment := range lit.LineComment.List {
+					buf.WriteString(", " + comment.Text)
+					buf.WriteString("\n")
+				}
+			} else {
+				if multiline {
+					buf.WriteString(",\n")
+				} else if i < len(tv.List)-1 {
+					buf.WriteString(", ")
+				}
 			}
 		}
 		buf.WriteString("]")