From 1bb47ab9a56f8cc2aa08706d88887bc888cbd063 Mon Sep 17 00:00:00 2001
From: Martin Atkins <mart@degeneration.co.uk>
Date: Tue, 16 Apr 2019 13:28:12 -0700
Subject: [PATCH] configs/configupgrade: Preserve comments on items in object
 exprs

The expression upgrade functionality mostly ignores comments because in
the old language the syntax prevented comments from appearing in the
middle of expressions, but there was one exception: object expressions.

Because HCL 1 used ObjectType both for blocks and for object expressions,
that is the one situation where something we consider to be an expression
could have inline attached comments in the old language.

We migrate these here so we don't lose these comments that don't appear
anywhere else. Other comments get gathered up into a general comments
set maintained inside the analysis object and so will be printed out as
required _between_ expressions, just as they did before.
---
 .../test-fixtures/valid/noop/input/resources.tf     |  5 +++++
 .../test-fixtures/valid/noop/want/resources.tf      |  5 +++++
 configs/configupgrade/upgrade_expr.go               | 13 +++++++++++++
 3 files changed, 23 insertions(+)

diff --git a/configs/configupgrade/test-fixtures/valid/noop/input/resources.tf b/configs/configupgrade/test-fixtures/valid/noop/input/resources.tf
index 29ceef046..17f3f8c88 100644
--- a/configs/configupgrade/test-fixtures/valid/noop/input/resources.tf
+++ b/configs/configupgrade/test-fixtures/valid/noop/input/resources.tf
@@ -1,5 +1,10 @@
 
 resource "test_instance" "example" {
+  tags = {
+    # Thingy thing
+    name = "foo bar baz" # this is a terrible name
+  }
+
   connection {
     host = "127.0.0.1"
   }
diff --git a/configs/configupgrade/test-fixtures/valid/noop/want/resources.tf b/configs/configupgrade/test-fixtures/valid/noop/want/resources.tf
index 29ceef046..17f3f8c88 100644
--- a/configs/configupgrade/test-fixtures/valid/noop/want/resources.tf
+++ b/configs/configupgrade/test-fixtures/valid/noop/want/resources.tf
@@ -1,5 +1,10 @@
 
 resource "test_instance" "example" {
+  tags = {
+    # Thingy thing
+    name = "foo bar baz" # this is a terrible name
+  }
+
   connection {
     host = "127.0.0.1"
   }
diff --git a/configs/configupgrade/upgrade_expr.go b/configs/configupgrade/upgrade_expr.go
index 2f525a3b1..5d62643ba 100644
--- a/configs/configupgrade/upgrade_expr.go
+++ b/configs/configupgrade/upgrade_expr.go
@@ -192,9 +192,22 @@ Value:
 			diags = diags.Append(moreDiags)
 			valueSrc, moreDiags := upgradeExpr(item.Val, filename, interp, an)
 			diags = diags.Append(moreDiags)
+			if item.LeadComment != nil {
+				for _, c := range item.LeadComment.List {
+					buf.WriteString(c.Text)
+					buf.WriteByte('\n')
+				}
+			}
+
 			buf.Write(keySrc)
 			buf.WriteString(" = ")
 			buf.Write(valueSrc)
+			if item.LineComment != nil {
+				for _, c := range item.LineComment.List {
+					buf.WriteByte(' ')
+					buf.WriteString(c.Text)
+				}
+			}
 			buf.WriteString("\n")
 		}
 		buf.WriteString("}")