Merge pull request #25381 from hashicorp/alisdair/013upgrade-preserves-more-comments

command: Fix 0.13upgrade to preserve more comments

Author: alisdair

command/013_config_upgrade.go

@@ -404,7 +404,18 @@ command and dealing with them before running this command again.
 			} else {
 				attributesObject = cty.EmptyObjectVal
 			}
-			body.SetAttributeValue(localName, attributesObject)
+			// If this block already has an entry for this local name, we only
+			// want to replace it if it's semantically different
+			if existing := body.GetAttribute(localName); existing != nil {
+				bytes := existing.Expr().BuildTokens(nil).Bytes()
+				expr, _ := hclsyntax.ParseExpression(bytes, "", hcl.InitialPos)
+				value, _ := expr.Value(nil)
+				if !attributesObject.RawEquals(value) {
+					body.SetAttributeValue(localName, attributesObject)
+				}
+			} else {
+				body.SetAttributeValue(localName, attributesObject)
+			}
 
 			// If we don't have a source attribute, manually construct a commented
 			// block explaining what to do

command/testdata/013upgrade-preserves-comments/expected/main.tf

@@ -9,8 +9,15 @@ terraform {
       source  = "hashicorp/bar"
       version = "0.5.0"
     }
+    # An explicit requirement
+    baz = {
+      # Comment inside the block should stay
+      source = "foo/baz"
+    }
+    # Foo is required
     foo = {
-      source = "hashicorp/foo"
+      source  = "hashicorp/foo"
+      version = "1.0.0"
     }
   }
 }

command/testdata/013upgrade-preserves-comments/input/main.tf

@@ -6,5 +6,15 @@ terraform {
   required_providers {
     # Pin bar to this version
     bar = "0.5.0"
+    # An explicit requirement
+    baz = {
+      # Comment inside the block should stay
+      source = "foo/baz"
+    }
+    # Foo is required
+    foo = {
+      # This comment sadly won't make it
+      version = "1.0.0"
+    }
   }
 }